Document V35VByk1xzzqg8VeYvO231ga8

) American Water Works Association ANSI/AWWA C401-83 (Revision of AWWA C401-77) AWWA STANDARD PRACTICE tor THE SELECTION OF ASBESTOS-CEMENT DISTRIBUTION PIPE 4 IN. THROUGH 16 IN. (100 mm THROUGH 400 mm), FOR WATER AND OTHER LIQUIDS eMCAN NATIONAL] * STANOAADI First edition approved by A WWA Board of Directors Jan 27, 1964. This edition approved Jan. 30, 1983. Approved by American National Standards Institute. Inc., June 21. 1983. AMERICAN WATER WORKS ASSOCIATION 6666 West Quincy Avenue, Denver, Colorado 80235 CTD031609 > Committee Personnel The Standards Committee on Asbestos-Cement Pressure Pipe, which reviewed and approved this standard, had the following personnel at the time of approval: R.S. Bryant, Chairman J.L. Warden, Vice-Chairman T.R. Gillen, Secretary Consumer Members S.C. B aker, Naval Facilities Engineering Command, Alexandria, Va. (NAVFAC) Gi envvood BRETZ.* USNCBC CESO, Port Hueneme. Calif. (NAVFAC) R.S. Bryvnt. Department of Water and Power, Los Angeles, Calif. (AWWA) Roger Graff, City of San Diego. San Diego, Calif. (AWWA) J.L. Wvrden, US Bureau of Reclamation, Denver, Colo. (BUREC) ) General Interest Members G C Anderson, Insurance Services Offices, New York. N.Y. R.A Barrows. C.E. Maguire. Inc., Waltham. Mass. Y.R. B ICR EL. Department of Environmental Health, Albuquerque. NM S L. Bishop.* Metcalf & Eddy. Boston, Mass. T.J Brown Jr.. Factory Mutual Research Corporation. Norwood. Mass. * F V C AM arda. Crown Point. Ind. C W Cl i.ne. Thompson & Litton, Inc.. Norton. Va. L .1 Do.nedlo, Underwriters' Laboratories. Northbrook. 111. C I. FRICK,* Insurance Services Office. Atlanta. Ga. (ISO) INEWWA) (APWA) (N'EWWA) (FMR) ( AWWA) ( AWWA) (UL) (ISO) Copyright 8 1983 by American Water Works Association Printed in USA CTD031610 ASBESTOS-CEMENT DISTRIBUTION PIPE ^ R.S. Holmgren Jr.. James M. Montgomery Consulting Engineers, Pasadena. Calit. (AWWA) L.L Lues. W.M. Lyles Company. Visalia. Calif. (AWWA) F. V OBERC Metcalf & Eddy. Inc.. Boston. Mass. (WPCF) M R. Si CHOMEL.* Underwriters' Laboratories. Northbrook. 111. (UL) D.F. Thom as. Waterous Company. South St. Paul. Minn. (MSS) J.R. Wiliiwis. Fairfax. Va. (AWWA) Producer Members J.F. Baker. Certain-Teed Products Corporation. Valley Forge, Pa. T.R. Gillen.* Asbestos-Cement Pipe Producers Association. Lakewood, Colo. Glstavo Herrera, Asbestos Monterrey, S.A. Monterrey. N.L.. Mexico J.C. J \CKSON. Asbestos-Cement Pipe Producers Association. Arlington. Va. S.G. LEVSHOCK. Cement Asbestos Products. Birmingham. Ala. H L. Olson, Johns-Manville Sales Corporation. Denver. Colo. (AWWA) (ACPPA) (AWWA) (ACPPA) .(AWWA) (AWWA) " Micrnaie t CTD031611 Table of Contents SEC Foreword P*GE I. History of Standard ........................... II Major Revisions ............................... v v Standard 1 General............................................... II Scope...................................................... 1 2 References.............................................. 1.3 Symbols and Abbreviations............ 2 General Design ................................ 2.1 Strength and Design Factors........... 2 2 Combined Loading Theory............. 2.3 Three-Edge Vee-Shaped Bearing Load................................................... 3 External Loads................................ 3 I Introduction....................................... 3.2 Earth Loads...................................... 3 3 Superimposed Loads.......................... 4 Hydrostatic Pressure........................ 4.1 introduction....................................... 4 2 Operating Pressure............................ 4 3 Surge Pressure.................................... 5 Design Criteria and Use of Pipe Selection Charts .......................... 5 I Combined Loading Curves................. 5 2 Safety Factors....................................... 5 3 Lse of Selection Charts for Economical Design...................... 5.4 Discussion............................................ 5 5 Illustrative Problem on Pipe Selection............................................ I I I 2 4 4 6 7 7 7 7 17 20 20 20 20 20 20 21 21 21 22 Tablet F. I Conversion Factors.............................. 1 Recommended Safe Design Values of t for Tunnel Conditions........... 2 Impact Factors (F)............................. v 17 17 SEC 3 4 5 6 C.l Values of Load Coefficients Cf for Concentrated and Distributed Superimposed Loads Centered Vertically Over Conduit.......... Superimposed (Wheel) Load -- Single Wheel = 16000 1b (7250 kg).................................... Design Internal Pressure and Design External Load................ Design External Earth Load Present Worth of an Income of $ 1.00 per Year for the Next .V Years............................ . PACE 18 19 37 50 Figure# 1 Classes of Bedding for Conduits in Trench........................................ 2 Load Pressure Curve...................... 3 Assembly for Three-Edge Vee- Shaped Crushing Strength Test.............................................. 4 Classification of Construction Techniques.................................. 5 Values of Q for Trench Conditions.................................. 6 Embankment Conditions.............. 7 Values of C( for Positive Projecting Pipe ............................................ 8 Values of Bd B( at Which the Trench and Positive Projecting Pipe Equations Give Equal Loads .......................................... 9 Values of C,, for Negative Projecting Pipe and Imperfect Ditch Conditions........................ 10a Positive Projecting Pipe Projection X Ratio = -- B................................... 5 6 7 8 9 10 11 13 14 15 III CTD031612 asbestos-cement distribution pipe iv (Ob Negative Projecting Pipe Projection V Ratio = -- 3,.......................... 11 Projection Ratio p' for the Imperfect Trench Embankment Condition.......................................... 12 Values of CT for Tunnel Conditions........................................ 13 Superimposed Loads.......................... 14a Selection Curves for 4-in Asbestos-Cement Pipe.................. 14b Selection Curves for 6-in. Asbestos-Cement Pipe.................. 14c Selection Curves for 8-in. 15 15 16 19 23 24 Asbestos-Cement Pipe....... 32 !4D(m> Selection Curves for 250-mm Asbestos-Cement Pipe....... 33 !4E(m) Selection Curves for 300-mm Asbestos-Cement Pipe....... 34 !4F(m) Selection Curves for 350-mm Asbestos-Cement Pipe....... 35 14c (m) Selection Curves for 400-mm Asbestos-Cement Pipe....... 36 B. I Time (T) =* Effective for Full Cut Off Uniformiyat Maximum Rate.................................................. 42 C. I Yearly Power Cost to Compensate for Friction Loss of Head............ 48 Asbestos-Cement Pipe.................. 25 14r> Selection Curves for 10-in. Appendices Asbestos-Cement Pipe.................. 26 !4e Selection Curves for 12-in. A Friction Loss of Head Chart-- Asbestos-Cement Pipe.................. 27 Coefficient of Flow, C - 140 .... 39 O O O n-- Tf !4f Selection Curves for !4-m. B Surge Pressure Analysis ... Asbestos-Cement Pipe.................. 28 B.! Water Hammer or Surge .. !4g Selection Curves for !6-in. B.2 Water Hammer Analysis .. Asbestos-Cement Pipe.................. 29 B.3 Valve Closure .................... 14a (m) Selection Curves for lOO-mm B.4 Pumped Systems................ Asbestos-Cement Pipe......... 30 B.5 Methods of Control .......... 148 (m) Selection Curves for 150-mm B.6 Surge Calculation Example Asbestos-Cement Pipe......... 31 B 7 Air in Pipelines.................. 14c {ml Selection Curves for 200-mm C Frictional Power Requirements .... 47 CTD031613 Foreword This foreword is for information onl\ and is not a part of A WWA C40I. f. History of Standard The information contained in this stan dard was first published as A WWA Hand book H2. with AWWA Board of Direc tors' approval on Jan. 17, 1964. The designation was laterchanged to, AWWA C401-64. Originally, it covered sizes 4-36 in. (100-900 mm) although the design was primarily based on service conditions generally related to smaller (4-16 in. f 100 --f00 mm]) distribution sizes. In 1977 the standard was revised. The title was changed to indicate the pipe is intended lor use in distribution systems, and the size range was changed to limit the maxi mum size covered by this standard to 16in. (400-mm) diameter pipe. II. Major Revisions Major revisions in this edition consist ol the following: I. The lormat has been completely rev lsed so that the various sections in this standard correspond to the numbered sec tions in AWWA C403. Standard Practice for the Selection of Asbestos-Cement Transmission and Feeder Main Pipe, Sizes 18 in. Through 42 in. 2. Bedding condition descriptions and load factors used in calculating earth loads have been revised to correspond to those contained in ASCE Manual of Engineering Practice No. 37, Design and Construction of Sanitary and Storm Sewers (1976). 3. The three-edge vee-shaped bearing method of ASTM C500 has been speci fied for crush testing. 4. The appendix has been enlarged to present data on flow calculations using the Hazen and Williams formula and data on surge pressure analysis. 5. The impact factor table was revised to conform with impact factors recom mended by the American Association of State Highway and Transportation Offi ces (AASHTO). 6. Metric conversion of all dimen sions and physical requirements are in cluded in this standard (Table F. I). Metric dimensions are direct conversions of cus tomary US inch-pound units and are not those specilied in International Standards Organization (ISO) standards. Table F. I Conversion Factors Inch-Pound System Multiply By To Obtain 1nches Feet Pounds Per Square Inch Pounds Pounds Per Foot Pounds Per Square Fool Pounds Per Cubic Fool 25 4 0 3048 6 894757 4.44822 0 014594 0 0478803 16 0185 Millimetres Metres Kilopascals Newtons Kilonewtons Per Metre Kilonewtons Per Square Metre Kilograms Per Cubic Metre J American Water Works Association ANSI/AWWA C401-83 (Revision of AWWA C40I-77) A WWA Standard Practice for The Selection of Asbestos-Cement Distribution Pipe, 4 in. Through 16 in. (100 mm Through 400 mm), for Water and Other Liquids Section 1--General Sec. 1.1 Scope This standard has been prepared so that design engineers may quickly deter) mine the correct pressure classilication ot asbestos-cement distribution pipe to use under various combinations of internal pressure (static, operating, and surge) and external load (earth and superimposed live loads). Combined loading curves de picting the relationship between hydro static loading and external loading capa bilities are included to expedite the selec tion ol the correct pipe strength classiflcation. Note: Inlormation to assist the engi neer in selecting the most economical size ol pipe is in the appendices. Appendix A contains a t net ion loss ot head chart based on the Hazen and Williams formula. Appendix B is a detailed analysis of surge pressure lactors. Appendix C includes tables to assist the engineer in determining the yearly power costs to overcome fric tion loss of head. The appendices are for inlormation only and are not part of AWWAC40I. k III Pressure< lasses. Pipe pressure ' class designations ot 100. 150. and 200 refer to the similarly numbered classes specified in AWWA C400, Standard lor Asbestos-Cement Distribution Pipe.4 in. Through 16 in. (100 mm Through 400 mm) NIPS. for Water and Other Liquids." 1.1.2 installation. Detailed coverage of the installation ot asbestos-cement pipe can be found in AWWA C603, Standard for Installation of AsbestosCement Pressure Pipe. Sec. 1.2 References This standard references the following documents. They form a part of this standard to the extent specified herein. In any case ot conflict, the requirements of this standard shall prevail. SCHL.ICK, W. J. Supporting Strengths for Cast-Iron Pipe for Water and Gas Service. Bull. 146. Iowa State Col. Engrg. Exp. Sta. (June 1940). Design and Construe tion of Sanitary and Storm Sessers. Manual of Engrg. Prac. No. 37. Amer. Soc. Civ Engrs. New York (1976). KERR. S. L. Practical Aspects ot Water Hammer. Jour. A WWA. 40:6.699 (June 1948). I CTD031615 AWWA C40I-83 M arston. Anson. The Theory of External Loads on Closed Conduits in the Light of Latest Experiments. Bull. 96. Iowa State Col. Engrg. Exp. Sta. (1930). ASTM* C500, Methods of Testing Asbestos-Cement Pipe. Sec. 1.3 Symbols and Abbreviations Bc = Outside diameter of a pipe, in feet (metres). Bd -- Width of trench measured at the top of pipe, in feet (metres). B. F. = Bedding factor, which is a load factor correlating three-edge vee-shaped bearing test loads to field loads associated with specific bedding conditions. Bt = Maximum width of a tunnel excavation, in feet (metres). c = Coefficient of soil cohesion, in pounds per square foot (kilonewtons per square metre). Cc -- Load coefficient lor the posi tive projecting embankment condition. It is a function of the ratio HI Bc, the projection ratio p, and the settlement ratio rsd. Cd = Load coefficient for the trench condition. It is a function of the ratio Hj Bj and the backfill material. C, = Load coefficient for the nega tive projecting embankment condition, as well as the im perfect ditch condition. It is a function of the ratio H/ Bd. the projection ratiop'. and the set tlement ratio r,d. Cs = Load coefficient for concen trated or distributed superim posed loads. It is a function of the ratio Bc: 2H and the ratio L.2H for concentrated loads, or the ratio D2H and the Vmencan Society lor Testing and Materials. 1916 Race Si.. Philadelphia, PA 19103 ratio MI2H for distributed loads. Ct -- Load coefficient for tunnel con ditions. It is a function of the ratio HI Bt and the type of soil surrounding the tunnel. D -- Width of the area over which the distributed superimposed load acts, in feet (metres). F -- Impact factor. H = Depth of cover, in feet (me tres), for all conditions except the tunnel condition. For the tunnel condition, H is the dis tance from the ground surface to the top of the tunnel excava tion. in feet (metres). k = Rankine's ratio of lateral earth pressure to vertical pressure. L -- Effective length of the pipe, in feet (metres). For pipe less than 3 ft (I m), the actual length of the section should be used. For all other lengths, an effective length of 3 ft (1 m) should be used. M = Length of the area over which the distributed superimposed load acts, in feet (metres). P = Internal pressure, in pounds per square inch (kilopascals), that the pipe will withstand when no external load exists. Pc = Concentrated loads, in pounds (kilonewtonsf). Pd = Distributed load, in pounds per square foot (kilonewtons per square metref). P0 = Static, working, or operating pressure, in pounds per square inch (kilopascals). Pc = Surge pressure or water ham mer, in pounds per square inch (kilopascals). *Note: P, and Pj are loads measured as a mass. However, to use them in equations using SI units the mass unit must be converted to force by multiplying times 9.807 (g. the acceleration ol gravity). ASBESTOS-CEMENT DISTRIBUTION PIPE 3 PT = Total internal pressure, in pounds per square inch (kilopascals). above which, in com bination with some external load WT applied in three-edge vee-shaped bearing, the pipe will withstand. p = Projection ratio lor the posi tive projecting embankment condition. It is defined as the ratio of the distance that the top of the pipe projects above the original ground surface in feet (metres) to the outside diameter of the pipe in feet (metres). (See Figure 10a.) p' = Projection ratio for the nega tive projecting and imperfect ditch condition. It is defined as the ratio of the vertical dis tance from the original ground surface down to the top of the pipe, in feet (metres), divided by the width of the trench, in feet (metres), for negative pro jection, and as the ratio of the vertical distance from the top of the excavated trench down to the top of the pipe, in feet (metres), divided by the diam eter ol the pipe, in feet (me tres). for the imperfect ditch condition. (See Figure lOBand Figure II.) r,d = Settlement ratio for positive projection, negative projection, and imperfect ditch condi tions. S.F. = Safety factor. n = The coefficient of internal fric tion ol backfill material, ju' = The coefficient ot friction be tween backfill material and the trench wall. If = External load, in pounds per linear toot (kilonewtons per metre), of pipe in the threeedge vee-shaped bearing test that the pipe will withstand when no hydrostatic pressure exists. WE = Total earth load, in pounds per linear foot (kilonewtons per metre), to which the pipe is subjected. Ws = Total superimposed load, in pounds per linear foot (kilo newtons per metre), of pipe transmitted through the bur ial environment to the pipe by factors other than the earth loads. W,, = The concentrated superim posed load, in pounds per linear toot (kilonewtons per metre), of pipe transmitted through the burial environ ment to the pipe by factors other than the earth loads. Wsd = Distributed superimposed load, in pounds per linear foot (kilonewtons per metre), of pipe transmitted through the burial environment to the pipe by factors other than the earth loads. WT = Total external load, in pounds per linear foot (kilonewtons per metre), of pipe applied in three-edge vee-shaped bearing above which, in combination with some internal pressure PT, the pipe will withstand. mv = Weight ol earth, in pounds per cubic toot (kilonewtons per cubic metre*). "Density, as used in the equations m this stand ard. refers to torceexerted per unit volume underthe acceleration ot gravity, rather than mass per unit volume Where true density is known in pounds per cubic toot, that value should be used in equations using IS customary units, where true density is known in kilograms per cubic metre, it must be converted to newtons per cubic metre by multiplying times 9 807 (g. the acceleration ot gravity) bet ore the value is used in equations using SI units. CTD031617 AWWA C40 1-83 Section 2--General Design I Sec. 2.1 Strength and Design sity! backlill; and 3.4 lor reinlorced con Factors crete with/; =0.4 percent, in whichp is the The strength ot asbestos-cement distri bution pipe must be sufficient to with stand the combined forces of all types ot internal pressures (static, operating, and surge) and external loadings (earth. h\e. and impact!. Sound engineering practice also requires that adequate safety factors be applied to strength requirements to ensure performance under other than ideal or calculated loading conditions. The magnitude ot these safety factors is in\ersel> proportional to the confidence that the designer has in engineering esti mates ot actual operating conditions. Safe ty factors are included under Sec. 5. 2.1.1 Bedding londmons. The bed ding conditions described below and shown in Figure I have been selected as representative ot typical installation con ditions encountered in the field. 2 1.1 I Class A--concrete cradle or concrete arch bedding. This class of bed ding mas take either ol two forms: 2.1.1.1.1 Concrete cradle. The pipe shall be bedded in a monolithic cradle ot plain or reinforced concrete havinga min ratio of the area ot steel to the area at the invert. 2 1.1.1.2 Concrete arch. The pipe shall be bedded in carefully compacted granu lar material having a minimum thickness ot one-fourth the outside pipe diameter (minimum of 4 in. [100 mm]) between barrel and bottom of trench excavation and extending hallway up the sides ot the pipe. The top hall ol the pipe shall be covered with a monolithic plain or reinlorced concrete arch having a minimum thickness of one-lourth the outside diame ter (minimum ot 4 in. [100 mm]) at the crown and having a minimum width equal to the outside pipe diameter plus X in. (200 mm). The load factor for Class A concrete arch type bedding is 2.8 lor plain concrete; up to 3.4 lor reinforced concrete with p = 0.4 percent; and up to 4.8 tor W reinforced concrete with p = 1.0 percent, in w hich p is the ratio ot the area ot steel to the area ot concrete at the crown. 2.1.1.2 Class B--lirst class bedding. Class B bedding may be achieved bv either ot two construction methods. imum thickness ot one-lourth the outside 2.1 1.2.1 Shaped bottom with care pipe diameter (minimum ot 4 in. [100 fully compacted backlill. The bottom of mm]) under the barrel and extending up the trench excavation shall be shaped to the sides lor a height equal to one-lourth conform to a cylindrical surlace with a the outside diameter. The cradle shall radius at least 2 in. 150 mm) greater than ha\ e a w idth at least equal to the outside the radius to the outside of the pipe and diameter ol the pipe barrel plus X in. (200 with a width sufficient to allow six-tenths mmi. Backfill shall be compacted above ot the width ot the pipe barrel to be the cradle and extending to 12 in (300 bedded in tine granular till placed in the mmi above the crown ol the pipe The shaped excavation Carefully compacted load (actor tor Class \ concrete cradle backlill shall be placed at the sides ot the bedding is 2 2 lor plain concrete with pipe to a thickness ol at least 12 in (300 lightly compacted (85 percent to 95 per mm) above the top ol the pipe. Shaped cent proctor or 40 percent to '0 percent trench bottoms are difficult to achieve relative density) backlill: 2.8 tor plain under current construction techniques. concrete with carefully compacted (95 2.1.1.2.2 Compacted granular bed- A percent proctor or 70 percent relative den ding with carefully compacted backlill. W CTD031618 ASBESTOS-CEMENT DISTRIBUTION PIPE 5 Shaped bottom with tamped backfill, load factor 1 9 CLASS B Compacted granular bedding, load factor 1.9 Flat bottom, load factor 1.1, impermissible bedding, not recommended loose backf<ll 'Carefully compacled backfill 95% proctor or 70% relative density Lightly compacted backfill 85-95% proctor or 40-70% relative density Figure 1. Classes of Bedding for Conduits in Trench \ o TE. In roi k (reru h. e xcaui te ai least 6 in (150 mm) below the c ouphng of the pipe e xcept where concrete cradle :s used Revised and reprinted with permission from ASCE, Manual 37, D9tign and Construction ot Sanitary and Storm Sewara. 1976. CTD031619 A W W A C401-83 I ho pipe shall ho bedded in compacted granular material placed on a Hat trench bottom. The granular bedding shall have a minimum thickness ol one-tourth the outside pipe diameter (minimum ot 4 in. [100 mm]) and shall extend haltway up the pipe barrel at the side. The remainder ot the baektill to a minimum depth ot 12 in (.'00 mmloverthetopol the pipe shall be lilled unh highly compacted material. 2.1.1.2.2 The load lactor tor either construction method is 1.9, 2.1.1.2 Class C--ordinary bedding. Class C ordinary bedding may be achieved by either ot two construction methods: 2.1.1.2.1 Shaped bottom. The pipe shall be bedded with "ordinary"care in an earth foundation lormed in the trench bottom by a shaped excavation that will tit the pipe barrel with reasonable close ness lor a width ot at least 50 percent ot the outside pipe diameter. The side tills and area over the pipe to a minimum depth ol 6 in. (150 mml above the top ol the pipe shall be tilled with lightly com pacted till. The shaped bottom bedding is not recommended tor pipeline construc tion because it is impractical and costly. 2.1.1.2.2 Compacted granular bed ding with a lightly compacted baektill. The pipe shall be bedded in compacted granular material placed on a flat trench bottom. The granular bedding shall have a minimum thickness ol 4 in. (100 mm) under the barrel and shall extend onetenth to one-sixth ol the outside diameter up the pipe barrel at the sides. The remainder ot the backfill to a minimum depthot6in.(l50mm)overthetopolthe pipe shall be tilled with lightly compacted backfill. 2.1 1.2 2 The load (actor tor either construction method is I 5. 2.1 1.4 Class D--Hat bottom trench, impermissible bedding. In this class ot bedding, the bottom ot the trench is left Hat. and no care is taken to secure com paction ot baektill at the sides and imme diately over the pipe. The load lactor tor Class D bedding is I. I. 2.1.1.4.1 Class D bedding is not rec ommended tor pipeline construction. Under present construction conditions. Class B or C bedding with a compacted granular bedding is generally a more prac tical and economical method ol installa tion. Sec. 2.2 Combined Loading Theory Tests of asbestos-cement pipe under various combinations ol internal pressure and external crush load applied in threeedge vee-shaped bearing (see Sec. 2.2) shows that there is a relationship between the combined loads at the point of pipe fracture. This relationship can be repre sented by a parabolic curve as shown in Figure 2. The equation for the load pres sure parabolic curve, which is known as the Schlick formula, may beexpressed as: P represents the internal pressure; W the external load. Figure 2. Load Pressure Curve CTD031620 \SBESTOS CEMENT DISTRIBUTION PIPE 7 Sec. 2.3 Three-Edge Vee-Shaped Bearing Load T he combined loading curve shown in Figure 2 is calculated on the basis ot crush strengths determined by laboratory tests employing the three-edge vee-shaped hearing test method I see \STM C500. Methods ol Testing \sbestos-Cement Pipe and Figure el. Because the Iteld-supporting strength ol a pipe is inlluenced by the bedding conditions and by the lateral pressure acting against the sides ol the pipe, it is necessary to apply a bedding load laetor to the laboratory three-edge vee-shaped bearing loads to correlate them to the actual field loads. Since the external load equals the bedding laetor times the vee-shaped bearing load, the bedding fac tor equals the external load divided by the three-edge vee-shaped bearing load. Fig ure 1 shows the load factors to be applied lor each bedding class. 12"(305mm) minimum 12'(305mm) minimum Figure 3. Assembly for Three-Edge Vee-Shaped Crushing Strength Test Section 3--External Loads Sec. 3.1 Introduction For the design ol asbestos-cement dis tribution pipe, external loads IT'r are detined by the following equation: - wy _, Hr= -7FFT X(SF| E<2 Sec. 3.2 Earth Loads Earth loads W to which pipe is sub jected are a function ol the soil density, pipe diameter, depth ol cover, and con struction techniques employed in laying the pipeline. They depend on the interplay between the weight ot the prism ot earth directly over the pipe, called the interior prism, and the frictional shearing forces, plus or minus, transterred to that interior prism by the adjacent outside prisms of earth. The magnitude ol earth loads varies with the construction technique employed. There are two major construction tech niques normally encountered: trench and embankment. Another technique, the tun nel condition, is not normally tound. but nevertheless, has unique design methods, which make its inclusion in thisdiscussion necessary. Figure 4 shows these three con struction techniques. 8 XVVWA C401-83 32 1 \lar\ion\ equation. For asbes tos cement distribution pipe design, earth loads are calculated b> the general form of Marston's equation: H f = Cu.fi/ Eq 3 NOTE: Density as used in this equation and the following equations actually re fers to lorce exerted per unit volume I pounds percubic loot or kilonewtons per metrel under the acceleration ol'gravity, rather than mass per unit volume. Where true densitv is known in pounds percubic foot, that value should be used in equa tions using US customary units; where true density is known in kilograms per cubic metre, it must be converted to new tons per cubic metre by multiply ing times 9.807 (g, the acceleration ofgravity) before the value is used in equations using SI units. Soil densities n\. range in value trom 100 to 135 lb cu It (16 to 21 k\ mJ). In the absence ot actual site information, a value of 120 lb cu It (19 kN m') is recommended for asbestos-cement dis tribution pipe design. 3.2.1.1 C is a coefficient that is de pendent on: 1. Ratio of the height of fill to the width o( trench or pipe diameter. 2. Shearing forces between the inte rior and adjacent earth prisms. 3. Direction and amount of relative settlement between interior and adjacent earth prisms tor embankment conditions. The calculations used to find the value B, *itrnn required hmit. otherwise conduit i$ positive proiectmg Figure 4. Classification of Construction Techniques Reprinted with permission trom ASCE, Manual 37, Design and Construction ot Sanitary and Storm Sawars. 1976. XSBESTOS-CEVIENT DISTRIBUTION PIPE 9 Values ol coefficient Cd or C, Figure 5. Values of C,/ for Trench Conditions Reprinted with permission from ASCE, Manual 37. Design and Construction of Sanitary and Storm Sewers. 1976. ol the coefficient vs ill depend on the instal lation conditions emplosed in las in it the pipe. 3.2 I 2 Values tor B, and C must be determined to calculate earth loads hs Eq 3 lor the trench, embankment, and tunnel construction techniques The tollossing subsections describe the different condi tions and explain the methods tor finding the salues needed to use Vlarston's equa tion tor soil loading. 3 2 2 Trent h t omhtion. \ trench con dition is delined as that in sshich the pipe is installed in a narross trench, generally CTD031623 10 AWWA C40I-83 less than two to three diameters in width, cut in undisturbed ground, and backfilled to the original ground surface, as illus trated in Figure 4. For this condition. Eq 3 is rewritten as: We = Cjh\ Bs Eq 4 3.2.2.1 The values of Gare obtained from Figure 5, in which curves A. B. C. D. and E take into account the friction coef ficient between the backfill and the sides of the trench for the various soil composi tions likely to be encountered. Curve A is for granular materials without cohesions. Curve B is for sand and gravel. Curve C is tor saturated topsoil. Curve D is for clay. Curve E is for saturated clay. 3.2.3 Embankment condition. An embankment condition is defined as either that condition where the pipe is installed in a trench that is wider than two to three pipe diameters and that is cut in undis turbed ground, or that condition where the pipe is covered with fill above the original ground surtace. Embankment conditions are further subdivided into positive and negative projecting pipe cat egories. depending on the location of the top ot the pipe relative to the original undisturbed ground. A special case where compressible material is used as part of the backfill, called an imperfect trench. also is classified as an embankment condi tion. The various embankment conditions are illustrated in Figures 4 and 6. 3.2.4 Positive projecting pipe condi tion. A positive projecting pipe condi tion is defined as either that condition where the pipe is installed in a trench cut in undisturbed ground that is wider than two to three pipe diameters, or that condi tion where the top of the pipe is above the adjacent original ground surface and cov ered with fill above the original ground surface. For this condition, Eq 3 is rewrit ten as: W = Cm,Bp Eq 5 3.2.4.1 The values of O are obtained from Figure 7. C. also may be obtained from Eq 6 when the following conditions exist simultaneously: 1. The ratio Hi B, is greater than 1.3 2. The product p (r,j) = 0.7 C = 1.892//. B, - 0.96 Eq 6 3.2.4.2 The recommended value for the settlement ratio r,j is +0.7 for asbes tos-cement distribution pipe design. 3.2.5 Transition width. It will be noted from the preceding discussion that under construction conditions where a trench is cut in undisturbed ground two methods of computing the earth load are :renck equation i Eq 4) cc The trench width is the transition width; earth loads are computed by either Eq 4 or Eq 5. 'id and ee The trench width is greater than the transition width; earth loads are computed by the positive projecting pipe embankment equation {Eq. 5). For a given depth of cover the earth loads resulting from trench widths cc, dd, and ee are equal. Figure 6. Embankment Conditions ASBESTOS-CEMENT DISTRIBUTION PIPE II o w (O > Figure 7. Values of C, for Positive Projecting Pipe Reprinted with permission from ASCE, Manual 37, Design and Construction otSsnltsry and Storm Sewers. 1976. available (I) the trench condition and (2) width is theoretically the maximum exter the positive projecting pipe embankment nal earth load that can be transmitted to condition. The method chosen is depend the pipe lor any given depth of cover. For ent on the ratio ol the trench width to the all trench widths greater than the transi pipe diameter. As previously stated, w hen tion width, earth loads are computed by the trench width is less than two to three the positive projecting pipe embankment times the pipe diameter, earth loads are condition equation (Eq 5). In this latter computed by the trench condition equa case and lor a given depth ol cover, the tion ( Eq 4). The width ol trench at which earth loads are equal to the load that both methods ol computation give equal results at the transition width and that is j loads is called the transition width. The computed by the trench condition equa earth load computed at the transition tion (Eq 4). (See Figure 6.) CTD031625 i: AWWA C40I-83 3.2.5 I The transition width is deter mined from Figure 8 by multiplying the applicable ratio B.i, B, by the applicable pipe outside diameter Bc. The applicable ratio of trench width to pipe outside diameter. Bj B,, can be obtained from Figure 8 tor any given ratio of backfill height to pipe outside diameter. HI Bt. 1 2.6 Xegaiive projei tingpipe embank ment londinon. A negative projecting pipe condition is defined as that condition where the pipe is installed in a relatively shallow trench wherein the top of the pipe is at some elevation below the original ground surface. The trench is then back filled and compacted, and embankment is constructed thereon to finished grade (Figure 4). For this condition. Eq 3 is rewritten as: W'f = C,,u,Bs Eq 7 3.2.6.1 The various values of C,, are obtained from Figure 9. For asbestoscement pipe design the recommended value lor the settlement ratio r,,/ is zero. 3 2.6.2 When calculating earth loads under negative projecting pipe embank ment conditions, consideration must be given to the transition width as defined in Sec. 3.2.5. For values of the ratio BjI B, less than those given in Figure 8. the load on a pipe is determined Irom Eq 7 tor negative projecting pipes. However, as the trench width increases and the ratio Bj! B, becomes greater than that given in Figure 8. the earth load should be determined from Eq 5 for positive projecting pipes. Adherence to the preceding rule will result in the most realistic earth loads tor design purposes. 3 2.7 Imperfect treni h condition. The imperfect trench condition occurs rather infrequently and is included (or general information. The imperfect trench embank ment condition refers to that construction technique wherein the pipe is first in stalled as a positive projecting pipe. A portion of the embankment is then built up to some elevation above the pipe top and thoroughly compacted as it is placed. A trench the same width as the pipe is then excavated directly over the pipe down to or near to its top and subsequently back filled with loose compressible material. The remainder of the embankment is then built up to final elevation (Figure I I). For this condition. Eq 3 is rewritten as: | Wc = Eq 8 3.2.7.1 The various values of C,, are obtained from Figure 9. For asbestoscement pipe design the recommended value for the settlement ratio rSd is equal to -0.3. 3.2.8 Tunnel conditions. There are two types of tunnel construction encoun tered in normal pipe laying operation. 3.2 8.1 The first type is the most Irequently encountered and occurs when a sleeve of a larger diameter than the speci fied pipe is first jacked through an em bankment. The pipe is then placed into the sleeve without becoming an integral part of the tunnel construction. In this example, the sleeve supports the entire earth load and the pipe contained therein is not subjected to crushing loads. When selecting the required pipe classification lor this condition, only the internal pres sure needs to be considered for design. * 3.2.8.2 The second type of tunnel condition is rarely encountered in distri bution pipe work but is discussed here lor completeness. It occurs when the pipe itself must carry the entire load. The area through which the pipeline must pass is bored and braced with the necessary sup ports. The pipe then is placed in the tun nel. and the void between the pipe and tunnel braces is backfilled with compacted earth, grout, or concrete. Once this opera- j. tion is completed, the earth load automat- " CTD031626 R e p rin te d w ith p e rm issio n from ASCE, M anual 37, D e sig n a n d Construction otSonltsry and S to rm Sewers. 1976. CTD031627 u AWWA C401-83 ) Coefficient C,, Figure 9. V alues of Cn for Negative Projecting Pipe and Imperfect Ditch Conditions Reprinted with permission from ASCE, Manual 37, Design and Construction ot Sanitary and Storm Sawors. 1976. CTD031628 V.SBESTOS CEMENT DISTRIBUTION PIPE 15 Figure 10Positive Projecting Pipe Projection Ratio = __1_ S, Figure 10b. Negative Projecting Pipe Projection Ratio =__ 1_ Bj Top of embankment / Compressible backfill Proiection ratio = - 3c f x 1__ i Figure II. Projection Ratio p for the Imperfect Trench Embankment Condition CTD031629 16 AWWA C40I-83 I Values of H /B t 0 1 2 345 Values of coefficient Cj Figure 12. Values of Cj for Tunnel Conditions Reprinted with permlsaion from ASCE. Manual 37,0tlgnin<IConttnicttonofStnlt*ry*ndStormSw*n. 197*. ( CTD031630 ASBESTOS-CEMENT DISTRIBUTION PIPE 17 ically transfers from the tunnel supports to the pipe itself. For this condition, Eq 3 is rewritten as: Wt = CtBt{h,Bt -- 2c) Eq 9 3.2.8.3 Values of Cr for different types ot soil are obtained from Figure 12. If the value for the coefficient of cohesion is not available from laboratory tests, then the recommended safe design values in Table I are to be used. Table 1 Recommended Safe Design Values of c for Tunnel Conditions Materials Clav. very soft Clav. medium Clay, hard Sand, loose drv Sand, stItv Sand, dense Top soil, saturated Values or ( Ik;ft ' (k S!m2) 40 (1.63) 250(10.19) 1000 (40.77) 0(0) 100(4.007) 300(12.23) 100 (4.007) 3.2.8.4 When, in tunnel construction, the excav ation becomes excessive, or when the void surrounding the pipe or tunnel lining is not carefully filled, or when the cohesion of the undisturbed material a bove the tunnel construction is destroyed by soil saturation or vibration, the earth load should be calculated using Eq 4 for trench conditions. Since it can be exceed ingly difficult to either predict or assess whether the tunnel excavation is exces sive. it is recommended that Eq 4 be used for most installations for safe asbestoscement pipe design. 3.2 8.5 It should be noted that the preceding discussion is based on the pre mise that the tunnel would be constructed in homogeneous soils that do not create unusual pressures and stresses. Tunnel construction should not be utilized through materials that tend to squeeze or swell, such as some types of clay or shale, or through blocky and seamy rock. Under these conditions, the construction method described in Sec. 3.2.8.1 is recommended. Sec. 3.3 Superimposed Loads Superimposed loads Ws are external loads other than the normal earth loads transmitted to the pipe. There are two types of superimposed loads as illustrated in Figure 13:(l)concentrated H/!i,and(2) distributed Wa. Superimposed loads are frequently referred to as live loads. 3.3.1 Concentrated loads. A concen trated load is a load caused by a single force, which may be either static or dy namic in nature. In normal pipe design, vehicular wheel loads are the most fre quently encountered concentrated loads. The magnitude of the load produced by concentrated superimposed forces is deter mined by: C.P F wu = Eq '0 (see Tables 2 and 3) 3.3.2 Distributed load. A distributed load is a load caused by a uniform force distributed equally over a given area. The load may be either static or dynamic in nature. The magnitude of the load pro duced by distributed forces is determined by: Wo = C.PjFB (see Table 4) Eq I I Table 2 Impact Factors F Depth of Cover fl(ni) Impact Factor F 1 0-2.0 (0.3 0 6) 2.0-3 0 (0 6-1.0) 3 0 or greater (1.0 or greater) 12 l1 10 IS AWWA C40I-8.1 0.0015 0 002 0.003 0.0035 0 004 0.005 0.0055 o c X rs i--, s r- 30 > *T 8888838 bbbbb S o V C 30 l> - W iA SSi?o3o rs o b d d do < O ^ O 30 - 3 dd 8 (2 44) O' n r- M a o 5T 1 O -- -- <n m n n dd sz c. C a-, r* ^ r * o d d d 5 rw -- ~ r-j cm -- A3 n n a o r odd d r*j ^-O-XiNO- r-i Tt r cm 5 d dddd - A N 5 (N A f' O' dodddd - C c -c r- t N rj o r c- <c A> d ri sn -- r ^ r- <r O 3s r~, r~~ -- IA5 1 j ' 7. - \Ai 5A Vi - - N (N n ^ ? c 36 o <n n o t I CTD031632 ASBESTOS-CEMENT DISTRIBUTION PIPE Table 4 Superimposed (Wheel) Load--Single Wheel = 16 000 lb (7250 kg) 19 Pipe Diameter--in imm) Cover Over Top ol Pipe u (m) 2 (0 611 2 5 (0 76) 3 (0 91) 4 (1 22) 5 II 52) 6 11 83) 8 (2 44) 10 13.05) 12 13 66) 16 (4 87) 20 (6.09) 6(150)* 797 (| | 6) 693(10.1) 425 (6.20) 256 (3 73) 176 (2.56) 149 (2 17) 69 (1,00) 43 (0.63) 37 (0.54) 21 (0.39) 5(0.07) 8 COO) 932 ( 13.6) 907(13 2) 544(7 93) 331 (4 83) 218(3 18) 197(2.87) 91 (1.33) 59 (0 861 48 (0 70) 27 (0.39) II (0.16) 10(250) 12(300) 14 (350) 16(400) Wheel Load -- Ih fi (K V m) 1272 (18 5) 1076(15.7) 693(10 1) 421 (6.14) 277 (4 04) 245(3 57) 112(1 63) 74 (1 08) 53 (0 77) 32 (0 47) 16 (0 23) 1488 (21.7) 1167(17.0) 816 (11.9) 490 (7.15) 330 (4.81) 235 (3.43) 139 (2.03) 85 (1.24) 59 (0 86) 37 (0.53) 21 (0.30) 1691 (24.7) 1237 (18.0) 933 (13.6) 565 (8.24) 378 (5.51) 267 (3.89) 160 (2.33) 96 (1 40) 69 (1 01) 43 (0.62) 26 (0.38) 1888 (27.5) 1382 (20.2) 1048 (15.3) 645 (9 41) 432 (6.30) 304 (4,44) 181 (2.64) 112(1.63) 80(1.17) 48 (0.70) 29 (0.42) For 4-m 1100-mm) pipe use same value as for 6-m (I50*mm) pipe Concentrated superimposed load, wsi, vertically centered over pipe. Distributed superimposed load, ws:, vertically centered over pipe. Figure 13. Superimposed Loads CTD031633 :o AWWA C401-83 Section 4--Hydrostatic Pressure Sec. 4.1 Introduction For t he design of asbestos-cement dis tribution pipe, the internal hydrostatic pressure Pr is defined by: Pt = (P* ~ P.) S.F. Eq 12 S.F. is the design safety factor. Safety factors are based on judgment, past expe riences. and sound engineering principles. For asbestos-cement distribution pipe, a safety factor of 4 is recommended when surge or water hammer is not calculated and added to operating pressure. Sec. 4.2 Operating Pressure The operating pressure P,, is the pres sure that exists under normal or steady conditions of operation. The pressure may be induced by pumps, gravity (such as the head created by a reservoir or ele vated water tank), or a combination of both pumps and gravity. Under a 100 per cent gravity situation, the pressure in the line at a given point is somewhat higher when there is no How and conditions are static. Under static conditions, the pres sure at a given point, measured in feet (metres) of head, is equal to the difference between the elevation of that point and the water surface level at the reservoir. Under Rowing conditions, the pressure at a given point is reduced by the amount of friction and other energy losses resulting from the How of water from the reservoir to that point. The magnitude of this head loss may be found by using the Hazen and Williams chart in Appendix A. In piping systems that have long runs with relatively few fittings and accessories, the recom mended value of C (coefficient of How) is 140. Sec. 4.3 Surge Pressure Surge pressures Ps are of a transient nature and are caused by unsteady or changing conditions in the pipeline. The terms water hammer, surge, or transient pressure are often used interchangeably to refer to these pressures, which are of brief duration but often of considerable magni tude. A variety of conditions may cause surge pressures. These include a valve opening or closing, sudden movement of air in a line, or a pump starting or stop ping. Surge pressures in a distribution sys tem can be of considerable magnitude, particularly when fire hydrants are rapidly opened or closed. The magnitude of this surge is difficult to determine and it is generally beyond the control of the design engineer as it depends on the speed at which the firemen open or close the hydrants. For this reason, design criteria for asbestos-cement distribution pipe in corporate a large minimum fixed safety factor of 4 to the operating or pressure class of the pipe to allow for an unknown amount of surge pressure that will occur in the system. Appendix B presents a dis cussion of surge pressures and how they may be controlled for the engineer who determines that surge should be incorpo rated in hydrostatic design calculations. Section 5--Design Criteria and Use Of Pipe Selection Charts Sec. 5.1 Combined Loading Curves Extensive testing and application of statistical analysis have shown that the strength characteristics of asbestos-ce ment pipe conform to the principles ol the combined loading theory developed by the late W.J. Schlick. This theory, com monly discussed in terms of the Schlick formula represented graphically as a pa rabola. is used as the basis for the design CTD031634 ASBESTOS-CEMENT DISTRIBUTION PIPE 21 and class selection of asbestos-cement distribution pipe. [See Figures 14a through l4Gand Figures l4A(m)through 14dm).] 5.1.1 Curve development. The fam ilies of selection curves presented in this standard were developed using the Schlick formula that establishes a functional rela tionship between external load and inter nal pressure. The external and internal load intercepts are tabulated in Table 5. Sec. 5.3 Use of Selection Charts for Economical Design The charts may be used conveniently by entering them through the depth of cover and bedding condition scale. The scales are correlated to the three-edge vee-shaped bearing equivalent of 2.5 times the earth load calculated using a soil density of 120 lb/cu ft (19 kN/m3) and a trench width equal to the inside diameter of the pipe plus 2 ft (0.6 m) (or the positive projecting conduit condition if lesser). Sec. 5.2 Safety Factors In the smaller diameters, the effect of water hammer generated by the opening and closing of fire hydrants can be of significant magnitude because of the high v elocities generated by open hydrant tlow conditions on small-diameter lines in dis tribution systems. It is difficult to evaluate accurately the magnitude of surges, and if calculated, it would be impractical to attempt to control the surge by the use of surge tanks or other devices. Rather than employ a rule-of-thumb surge allowance based on an assumed velocity change, a large minimum safety factor of 4 is app lied to the class pressure rating of the pipe to take into account the undetermined surges. 5.2.1 Design criteria. The design criteria for asbestos-cement distribution pipe is based on a design point on the combined loading parabolic curve where the following minimum conditions are met: (1) a factor of safety of 4 times the pressure class of the pipe (2) a factor of safety of 2.5 times the three-edge veeshaped bearing equivalent of an earth load calculated as 5 ft (1.52 ml depth of cover, a trench width equal to pipe inside diameter plus 2 ft (0.6 m) (or a positive projecting conduit condition if lesser), a soil density of 120 lb cu ft (19 kN mJ). and Class C bedding condition. 5.3.1 Design earth loads. Table 6 gives the design earth load values, which are obtained by calculating the external earth load based on a trench width equal to the I.D. of the pipe plus 2 ft (0.6 m) (or the positive projecting conduit condition if lesser). The earth load is then divided by the appropriate bedding factor for the class of bedding and multiplied by a safety factor of 2.5. The design earth load values from Table 6 can then be used to enter the selection curve charts using the design external load values given at the top of the selection curve charts. The field support ing strength listed for pipe so selected has been proved conservative during many years of performance under various field conditions. When there is an external condition that would warrant considering all external loading factors and/or a change in the safety factor, the equivalent external load should be determined and the selection chart entered at the proper value of the design external load scale found at the top of the chart. Sec. 5.4 Discussion AWWA C403, Standard Practice for the Selection of Asbestos-Cement Transmission and Feeder Main Pipe. Sizes 18 in. Through 42 in., is a standard contain ing information similar to that contained herein but dealing with larger diameter pipes. In AWWA C403 the design is based 21 AWWA C401-83 on evaluation of all design conditions including surge pressures. Adequate fac tors of safety are applied to the combina tion of loads to which the pipeline will be subjected. The primary differences be tween AWWA C40I and AWWA C403 are those of differing methods of design ing pipelines to account for interal and external load conditions. In the smaller sizes covered by AWWA C40I, surge pressures can be of great magnitude and are difficult or impractical for the engi neer to control in design. A large min imum safety factor of 4 is suggested to compensate for the unknown. In the larger sizes covered in AWWA C403, the design is based on an evaluation of surge pressure, which can be controlled in de sign. Calculated surge pressure is added to operating pressure before a safety factor of 2 is applied. For external loads, AWW A C401 considers only earth loads and a recommended safety factor of 2.5 is app lied. In AWWA C403, both earth loads and live loads are added before a factor of safety of 1.5 is applied to the combination of these external loads. In summary. AWWA C403 design is based on a more detailed evaluation of the magnitude of surge pressure and live loadings, and fac tors of safety based on this more precise knowledge of actual operating conditions are applied. Sec. 5.5 Illustrative Problem on Pipe Selection The application of the curves to design is shown in the following problem: Required: A 6-in. pipe to operate at a pressure of 120 psi at 8 ft depth of cover, bedding condition Class C, soil weight 120 Ib/cu ft. Solution: Enter the selection curve for 6-in. pipe at bedding condition Class C, 8-ft cover. The intersection of the 8-ft cover line with the 120-psi operating pres sure line falls between pipe classes 100 and 150. Use 6 in.. Class 150. The intersection of the 8-ft cover line with the Class 150 curve is at 140-psi operating pressure, or 560-psi design pressure. Therefore, the pressure safety factor equals 560/120 = 4.66, with a safety factor of 2.5 for exter nal earth load. | f t CTD031636 ASBESTOS-CEMENT DISTRIBUTION PIPE Dctlgn External load-lb./lln.ft. 23 Bedding C onditions Figure 14a. Selection Curves for 4-in. Asbestos-Cement Pipe CTD031637 B edding C o n d itio n * Design P r* iiu r* -p a l 24 AWWA C40I-83 Design External Load-lb/lln It Figure 14b. Selection Curves for 6-in. Asbestos-Cement Pipe CTD031638 ASBESTOS-CEMENT DISTRIBUTION PIPE 25 2 SO --i 2,000 Design External load-lb/lln ft 4.000 6,000 8,000 1 ----------1--------- ----------1---------- ----------1 10,000 ------ 1,000 Claes 200\ - 150 Class ISON Claes 10o\ 800 -- 00 -- 400 -- Bedding C onditions ______ 1______ i \ ______ l \ ______ 1______ i\ 2.5 5 8 III 12 16 20 III 2.5 SB 12 18 20 ____ 1_____ 1________1______LJ____________________________________ Oepth of Cover-ft Figure 14c. Selection Curves for 8-in. Asbestos-Cement Pipe CTD031639 26 AWWA C40I-83 02,0004,000 1 Design External Load-lb/Hn ft 6,0006,000 l ------------ 1------------ i i 10,000 i Bedding C onditions D esign P reeeure-pel Class 20<^^ Class 15(TS. Claes 100\ -- -- -- \-- - 2.5 5 11 A_ _________ l________ i 8 12 16 20 1 1 11 _______ i_______ 2.5 5 8 12 16 20 _____ 1_______ 1_________ 1__________1_____ LJ________________________________________ Depth of Cover-ft Figure 14D. Selection Curves for 10-in. Asbestos-Cement Pipe e CTD03164Q ASBESTOS-CEMENT DISTRIBUTION PIPE 27 Design External Load-lb/lln.tt. 0 2,000 4,000 6,000 8,000 10,000 Bedding C onditions Figure 14E. Selection Curves for 12-in. Asbestos-Cement Pipe CTD031641 28 AWWA C401-83 0*algn External Load-lb/lln ft 1 O perating Preeure~psi eelgn Preeeure-pel Figure 14f. Selection Curves for 14-in. Asbestos-Cement Pipe CTD031642 ASBESTOS-CEMENT DISTRIBUTION PIPE D<ign External i.oad-16/lln ft 29 Figure 14C. Selection Curves for 16-in. Asbestos-Cement Pipe CTD031643 10 0 AWWA C40I-83 Design External Load-kN/m 20 30 40 50 60 70 O perating Preeaura-kPa Daalgn Praseura~kPa Figure 14A(m). Selection Curves for 100-mm Asbestos-Cement Pipe CTD031644 ASBESTOS-CEMENT DISTRIBUTION PIPE 31 Oealgn External Load-kN/m 0 10 20 30 40 50 80 70 80 CTD031645 32 AWWA C40I-83 Daaign External load-kN/m I DilQn P rtu u rfk P a Figure 14r(m). Selection Curves for 200-mm Asbestos-Cement Pipe CTD031646 ASBESTOS-CEMENT DISTRIBUTION PIPE D*lgn External Load-kN/m 33 Figure 14D(m). Selection Curves for 250-mm Asbestos-Cement Pipe CTD031647 34 AWWA C40I-83 D**ln External Load-kN/m f O perating Pra*aura~kPa Figure 14E(m). Selection Curves for 300-mm Asbestos-Cement Pipe CTD031648 ASBESTOS-CEMENT DISTRIBUTION PIPE Daalgn External Load-kN/m 35 O perating P raaaura-kP a D atlgn Praaaura-kPa Figure 14F(m). Selection Curves for 350-mm Asbestos-Cement Pipe CTD031649 D ttiflR P ftllu rt-k P i 36 AWWA C401-83 D*algn External Load-kN/m Figure Nc(m|. Selection Curves for 400-mm Asbestos-Cement Pipe CTD031650 Table 5 Design In te rn a l Pressure am I Design E xternal L o a d ' 8 700 (127) 0 000(136) 0 300 (136) 11 000 (161) 11 800(172) 13 500(197) 15 400(225) ASBESTOS-CEMENT DISTRIBUTION PIPE ,5a "Ca x>>. < r-i 73 J c 3 8fpgggg -- 9A n /) 1/3 V5 /) 95 2 ? a c o c v3 Sc 3 30 30 30 30 30 s 0 -v -- ~ (N -- >0 rt ac 5 S p- x - - - -- - agga gz'. gogogcgin s *3 3^ sggggii - aaaaaaa a -O <N C*3 o X 'T 5 c O O >0 'C -O 'O o b oO 93 93 ^a Po'' Po- a Sg|3338 - a a a a 93 /I 93 -- 3< 3 u fl oo 15 o 0 o 3 o 0 o 0 o5 - <"-4 r**3 <""3 <*, h") a cu = ca car P 3a 9i-3 w8> --a ? 3. 5 2w-- 90--) C00M 9C03N Cc 9r0*"3, 05a 0 x 0 C4 ar >c i 37 CTD031651 AWWA C401-83 CTD031652 ASBESTOS -CEMENT DISTRIBUTION PIPE 39 Appendix A Friction Loss of Head Chart--Coefficient of Flow, C = 140 This appendix is (or information only and i.s not a part of A WWA C40I. Pipe Oiameter. inches Eo S-- oO v1 (JOOO oo55 * n0o (ro0t o*0- ^n- : O 4! ;' a; O 4) 2- o E a <j o 5oo iCfNli cn caCmno c^m --O _XJQ >co --yO) J5 n ya -O o 2t oo rc 2 fM9U| Mild CTD031653 40 AWWA C401-83 Appendix B Surge Pressure Analysis This appendix is for information only and is not a pari of A WWA C401. B.1 Water Hammer or Surge The slowing down or stopping of any moving mass requires a force or forces to counterbalance the kinetic energy that keeps the mass in motion. The faster a mass is decelerated and brought to a halt, the greater the force that is required. B.I.I Forces involved. It is some what of an oversimplification, but water hammer, or surge, can be defined in these terms: the closing of a valve or the stop ping of a pump causes a moving column of water in the pipeline to slow down and stop. The forces that bring about this deceleration are exerted radially on the moving water column by the pipeline walls. Conversely, the water exerts added pressure on the pipe, and the hoop stresses in the pipe walls thus increase over the normal operating pressure values. The faster the column of water is brought to a halt, the higher these stresses rise. B.1.2 Rate of velocity fluctuation. The pipe wall stresses are thus developed by. and increase in direct proportion to, the internal pressure that builds up as the column ol water decelerates. The slower the deceleration, the less the pressure builds up and the less the pipe wall stresses increase. It is. therefore, of importance to the pipe designer to know how to control the rate of velocity fluctuation, since by controlling this rate he controls the mag nitude of the pressure variations during the transitional periods. By such control he can keep the pipe wall stresses during surge to a predetermined value that will allow an economical installation. B.1.3 Wave motion. Water, being liquid, will act ina fairly complex manner when undergoing acceleration or deceler ation. Pressure waves are set up, which move along the pipeline at a rate of 2500-4500 ft/sec (760-1370 m/sec), the rate depending on the pipe wall material.. The waves will continue until they en counter a boundary condition, such as a reservoir, a closed valve, or a change in pipe diameter, at which point they will reflect back in the opposite direction. The wave motion will oscillate back and forth in the pipe until it is dampened out by the friction effects of the pipe walls. B. 1.4 Causes. The two major causes of water hammer or surge are: 1. The closing or opening, fully or partially, of a valve in a pipeline system. The valve may be in the line for one of a number of purposes. It could be a gate valve, float valve, pressure-reducing valve. or serve some other function. 2. The starting up or shutting down of a pump (switch or power failure). It can be seen that both of these occurrences cause changes in the velocity, and conse quently in the quantity, of water flowing in the pipeline. B. 1.5 Effects. Ignoring the effects of surge in the pipeline can lead to difficul ties after the line is in operation. Surge can result in damaged equipment and serious ly reduced capacity. B.2 Water Hammer Analysis The elastic wave theory for surge analy sis has been empirically established to be correct by many experiments, the first of w hich were performed as early as 1890. Its application to pipeline problems will yield results which are accurate and which may be relied upon for adequate analysis. B.2.1 Wave velocitv. Water ham- % CTD031654 ASBESTOS-CEMENT DISTRIBUTION PIPE 41 mer pressures are a function of the maxi mum rate ofchange of flow. When a valve is closed or a pump stops, a pressure wave is propagated along a pipeline. The veloc ity of the wave is the same as the velocity of sound in water, modified by physical characteristics of the pipeline: it is des cribed by the following equation: yt a-- ' per second (metres per second) g = acceleration due to gravity, 32.2 ft; sec2 (9.81 m/s2) B.2.3 Critical time. The longest elapsed time before final flow stoppage that will still permit this maximum pres sure to occur is called the critical time; it is simply the total length that the pressure wave travels in one cycle divided by the velocity of the wave. It is given by the following equation: Where a -- pressure wave velocity, in feet per second (metres per second) k = modulus of compression of water. 300 000 psi (2070 MPa) d = internal diameter of pipe, in inches (millimetres) E = modulus ol elasticity of asbes tos-cement pipe. 3 400 000 psi (23 400 MPa) e = wall thickness, in inches (milli metres) P, = velocity of sound in water, 4660 ft sec (1420 m. s) B.2.2 Maximum pressure. If the pressure wave is reflected back from a boundary condition, such as a reservoir, and returns to its initial position after the How in the line is completely stopped, then maximum water hammer pressure for those conditions will result. Stopping of the How may be effected by closing a valve or bv a pump stoppage. The magnitude of that maximum pressure is given by h=-- .? Eq B2 Where h = surge pressure, in feet of water (metres of water) I = velocity ol water in the pipeline during normal conditions, in leet per second (metres per second) a = pressure wave velocity, in feet U = --a Eq B3 Where V = critical time, in seconds L = distance within the pipeline that the pressure wave moves before it is reflected back by a boundary condition, in feet (metres) a = pressure wave velocity, in feet per second (metres per second) B.3 Valve Closure A valve in a water line may be of several different varieties, including gate, cone, and globe valves. When closing a valve, the area of the cross section of the pipeline that is progressively cut off is not gener ally proportional to the reduction in flow. In Figure Bl. Graph I presents a plot of stem travel versus How in the line for three types of valves. Note that the first 30-40 percent of stem travel has little effect on the flow in the pipeline. B.3.1 Effective time. As stated pre viously, water hammer pressure is a func tion of the maximum rate of change of flow. Therefore, if tangents to the curves in Figure Bl are drawn at the fastest rate of change(or steepest slope), the effective time of closure 77 is obtained. (See the curves in Figure Bl with tangents plotted and values of 77 determined.) This effec tive time 77 is the time that is used in water hammer calculations. In most cases, it is about one halt of the actual valve 42 AWWA C40I-83 closing time. This indicates that if the crit ical time of a certain installed valve is calculated from Eq B3 and found to be x seconds, then the actual time forcomplete valve closure that will cause maximum pressure to occur will be approximately 2x seconds. B.3.2 Relation to surge control. In the design ol a water system, one of the major considerations in the selection of a pipe is the design internal pressure that the pipe will be required to carry in service. The design internal pressure is the operat ing pressure plus the water hammer pres sure. In order to keep the water hammer or surge pressures at a controlled level, calculations must be made to determine the valve closure times that will be required to stay within the design pressure level. B.3.3 Determining effective time. Figure Bl presents a convenient threestep method for determining effective valve closure times for a given percentage of the maximum pressure (surge pressure when valve is closed in less than the criti cal time). Time --(Te) = Effective For Full Cut Off Uniformly at Maximum Rate Full Area Gate, 39.2%Tr Reduced Area Globe. W-------------------Te = 51.7% Tt -- l'4-Full Area Cone. TE = 48.6% Tt-*( * Open Percent Time of Valve Stem Travel - Tr ' Closed Percent of hmail (Instantaneous Closure) Percent Full Flow Figure B.l Time (Tf) = Effective for Full Cut Off Uniformly at Maximum Rate Reprinted by permission of the Johns-Manvllle Seles Corporation. ASBESTOS-CEMENT DISTRIBUTION PIPE 43 1. Determine the pipeline constant K given by Where K = pipeline constant a = pressure wave velocity, in feet per second (metres per second) V = velocity ol water in the How line under normal conditions, in feet per second (metres per second) g = acceleration due to gravity. 32.2 It sec- (9.81 m s;) h,, = operating pressure in the line under normal conditions, in feet ot water (metres of water) 2. Determine the maximum head that might be developed from the surge by using the formula hma, = aVfg. 3. Determine the percentage of hmax ( and find the corresponding effective clos ing time shown on the horizontal axis. This is given in units of 2Lfa, which represents the critical time for the pipe line. Note that the time determined is the effective closing time, and the actual time of valve stem travel is about twice as long. The reason lor this is that the first half of the closing ol the valve has little effect on the stoppage ol the How. It is the closing ol the final hall of the valve stem travel that closes ott the How. The second half is the etlective closing time. Therefore, two times the elfective closing time is the actual time ol the valve stem travel. B.4 Pumped Systems In relation to water hammerand surge, the most important elements in a system are pumps and valves. In a gravity system, only valves have to be considered. Both pumpsand valves must be considered in a pumped system. ^ B.4 I Complexit\. The surge anal' ysis ol a pumped system is more complex than in a 100-percent gravity system because 1. In a pumped system, the problem begins in the slowing down of the rising water column when the pump is shut off (because of power failure or otherwise). Consideration must be given to the time required for the pump to stop and for the flow to come to a halt. This involves the inertia of the motor and any llywheel in the assembly. Provisions normally should be made for slow opening and closing of pump control valves on pump systems. In a gravity system, the hydraulic problem consists only of stopping the descending water column. 2. In a pumped system, the pipeline profile is usually irregular, with successive high and low points and variable slopes. These conditions may give rise to water column separation, causing severe surges and operational troubles. Surges from water column separation do not follow a standard pattern and they have been mea sured at many times the calculated values. B.4.2 Alternative layouts. The de sign of a pumped system may involve the consideration of alternative layouts to keep surges and the consequent opera tional difficulties to a minimum. This work should be directed toward reducing the magnitude of surges and toward reduc ing the risk of water column separation that may be caused by the shutdown of a pump. B.4.3 Water column separation. Water column separation can be serious due to the large magnitude of the surges developed when the water column rejoins. It can occur: 1. At pump locations at the start of a steep main. 2. When the pressure at a high point falls below atmospheric, and air enters the line through air valves that may be located at a high point. 3. When the pressure falls to below the vapor pressure of water. 44 AW'WA C40I-83 B 4.4 Entrapped air. Waiercolumn separation can cause difficulties not only because of the before-mentioned surges set up by the rejoining of the water column, but because of the difficulties in getting air out ot the line on subsequent start-up. e\en with air valves. Entrapped air can cause How fluctuations and can seriously reducethecapacity of thesystem. B.S Methods ot Control The two types of surge to be controlled are negative surge and positive surge. The type is determined, ot course, by whether the surge pressures developed are below or above the normal static level. B.S. I Sedative surges. Negative surges in themselves are usually not dan gerous. except when they cause water column separation. If this occurs, extreme ly high positive surges result when the cavity closes, and this Irequently causes serious problems. The control ot both negative and positive surges should be given consideration. B.5.2 Surge control devices. Limit ing negative and positive surges is ac complished by several types ot surge con trol devices These devices include: I. Controlled valves. This is one ol the most elfecme means tor controlling positive surges. As explained previously, the rate ol opening and closing ot a valve can be calculated to allow an acceptable level ol surge. 2 Fly w heel on pump motor. In the event ot a power outage, the inertia ol the lly vvheel will keep the pump running lor a period ol time, during which it will gradu ally slow to a stop. This means that the water column in the pipeline will also be brought to a gradual stop, thus reducing the risk ol water column separation. 3 Standpipe. This is generally a tank with the surtace ol the water at atmospheric pressure It is. therelore. onlv practical at low heads. At a pump stop page and consequent reduced pressure. the reserve ot water in the tank Hows into the pipe and reduces the risk of water column separation. For positive surge control, the tank provides an outlet tor the built-up pressure in the system. 4. Air vessel or surge tank. This is an enclosed vessel containing air and water. It functions similarly to a stand pipe. with water reentering the line during negative surge and leavingduring positive surge. The major difference is that the air in the vessel is under pressure and much higher heads can be employed in the pipe system. 5. One-way surge tank. This is an adaptation ol the surge tank. It contains a check valve that permits watertoenterthe line during negative surge, but will not permit water to leave during positive surge. It is, therelore. only lor control of negative surges and is very ellective. 6. Reservoir ol water. This is sim ilar to the one-way surge tank, but pro- -s vides some control ol positive surge by permitting the slow entrance of water into the reservoir during a positive surge. 7. Suction pipe. This is a bypass around the pump Irom the suction side. It contains a check valve to prevent backtlow into the reservoir. It effectively redu ces negativ e pressure adjacent to the pump. 8. Surge relief valve. This is used lor controlling positive and negative surges The valve opens at a certain pressure and discharges water to relieve a surge --posi tive or negative. It must be carelullv designed and controlled in order to be effective. 9. Nonreturn valve. This is a check, strategically placed in a line, that can bring a small measure of relief to positive pressure. However, unless properly placed, it can lead to higher rather than lower surge. 10. Reversal ol pump. At pump stoppage, the column ol water reverses^^ itself. II the pump will not run backward to permit water to How back through it. VSBESTOS CEMENT DISTRIBUTION PIPE 45 then positive surges will be developed bv the sudden slopping ol the hackllovving column ol water. The pump should be designed to run reversed without damage to itsell. Design ol pumps that can run reversed without damage is a significant problem Other measures mav have to be taken B 5 3 Fuonomu < on\nleranon\. Prom an economic standpoint, it is usuallv worthwhile to properlv evaluate the surge potential in a svstem under design. The cost ol control devices may be bal anced against the added strength ol pipe, valves, and other equipment that will be needed it surges are not controlled, and the most advantageous conclusion reached. Manufacturers of surge control equip ment or consultants in this field should be sought lor advice in complex situations. 4660________ _ j X 10? X 24 3.4 X I O'- X 1.5 -- 3000 It sec. 2. Determine maximum surge pres sure if the valve closes within the critical time , of 3000 X 5 T= = 465 It ol water (300 psi| 3. Determine the critical time 2 L 2 X 5000 L a 3000 B.6 Surge Calculation Example The following example problem illus trates the calculation that may be fol lowed to determine valve closing time lor the control ol surge within prescribed limits. Problem: A 24-in. gravity transmis sion line is to operate at a pressure of 100 psi \ elocitv in the line is to be 5 ft sec. A valve is to be included in the line at a distance ol 5000 It Irom the reservoir. If positive surge pressure is to be controlled within 50 psi. determine the minimum nme tor valve closure. Assume that the ellective closing time is one hall of the actual valve stem travel time. IE lorasbeslos cement pipe = 3.4 X I06. wall thick ness is I 5 in . k tor water = 3 X 10s.) 'SolutionI. Determine surge wave velocity t, 4. Determine constant K for use in Graph 2 (Figure BI) of _ 3000 X 5 2gh,, ~ 2 X 32.2 X 231 10 5. Determine percent ot maximum surge pressure that should not be exceeded in the svstem 50 X 100 = 25 percent 6. Enter Graph 2 (Figure Bl) with percent ot (25 percent). Go horizon tally to the curves where K = 1.0. Read the effective closing time along the hori zontal axis. This value is 2.6 and is given in units ot 2L!a sec. The effective closing time in seconds would be 2L, a X 2.6 = 3.33X2.6 = 8.7 sec. The actual valve stem travel time would be twice this amount, or 17.4 sec. This calculated time (17.4 sec), therefore, represents the fastest allowable time the valve can be dosed in order to keep the surge pressure below the desired control level ol 50 psi. 46 A WWA C40I-83 B.7 Air in Pipelines Air in pipelines can cause serious oper ational difficulties, including reduction in capacity because of reduced cross-sec tional area and fluctuation in flow caused by expanding and contracting air in the line. These fluctuations in flow cause sud den movements of the air from one loca tion to another, followed by slugs of water, and this can cause serious surges. B.7:l Entrance of air. Air can enter a pipeline in many ways. It may enter at the intake. Entry may be caused by release of air from waterdue to temperature and pressure variation, or it may be caused by draining the line, or by draining parts of the line during normal shut-down. Nega tive surges may cause air to enter at air valves. Air should be prevented from entering the line in the first place. This is very important in order to reduce opera tional difficulties. Suggested solutions for control are as follows: 1. Intake. Correct design proce dures. provide low water-level pump cut off. 2. Release of air. Air is entrained in the water at intake and its release cannot be prevented. However, the quantities are not large and provisions for exhausting can be made by means of air valves. There are various types of air valves with differ ent functions, and the selection of the proper type and location for installation is essential. 3. Draining the line. Air cannot be prevented from entering the line on drain ing. of course. Large orifice air valves should be prov ided for exhausting the air during refilling. Draining and then refil ling does not often occur: therefore, long tilling times may be satisfactory. 4. Drainage during shut down. This can be a serious problem. Open stand pipes can be provided for air entry and exhaust. Sweeping air out using high velocities is another method. 5. Negative surges. The best way to prevent air from entering under these conditions is to design out the possibility of water column separation. Large vol umes of air may be involved here and can cause serious problems. Any one of the negative surge control devices described in Sec. B.5.2 will normally be adequate. B.7.2 Recommendations to combat air entrapment. Colorado State Univer sity has conducted studies to determine the effect of air entrapment in pipelines. The result of the studies proved that sud denly released entrapped air, under ap parently static conditions, creates a situa tion similar to that of classic water ham mer. Pressures are generated that may be on the order of 15 times the pipeline test pressure. Any pipeline material is serious ly affected by this rapid magnitude of load increase. Hydrostatic failure due to defec tive pipe may in all probability be traced to suddenly released entrapped air. The initial filling and testing of a pipeline is often the most critical period of its service life. Recommendations to combat air entrapment were made as follows: 1. Pipeline should be laid to grade wherever possible. 2. Automatic continual acting air re lease valves should be used at all high points. 3. Air should be bled from pipeline slowly. 4. Limit filling velocity in the pipeline to I ft, sec (3 m/s) or less. 5. Use dj D = 1 /10 to I /100. Where d -- diameter of air release valve. D = pipe diameter. The results of this study, together with the recommendations, have been found to be most useful to contractors in perform ing pipeline tests. Such recommenda tions also have been found to be useful to engineers from the standpoint of design J ing pipelines to minimize air problems. ^ ASBESTOS-CEMENT DISTRIBUTION PIPE 47 I Appendix C Frictional Power Requirements This appendix is for information only and is not a part of A WWA C401. The chart shown in Figure Cl permits rapid calculations of the yearly power costs to overcome friction loss of head. This chart is based on continuous pump ing operation (24 hours per day and 365 days per year), a power cost of SO.01 per kW-h. and a motor-pump efficiency of 100 percent. For actual operating condi tions and local power costs, appropriate factors must be applied to the values shown in the chart. By calculating power costs to overcome friction in two pipe sizes, or for two different types ot pipe having different flow coefficients, an an nual power cost savings can be deter mined. Economic justification for going \to a larger pipe diameter with lower -annual power costs can be determined by establishing the present worth of the annual savings using Table CI *, which is based on the discounted cash flow method. If the present worth of the annual savings based on established interest rates exceeds the added costs for the installation of a different size or type of material, then economicjustification exists for theadded capital expenditure. Nomograph values tor Figure Cl are based on the following: Cost per 1000 ft of pipe per year, in dollars Power cost = $0.01 kW-h Motor-pump efficiency (combined) = 100 percent Friction coefficient C -- 140 Continuous operation. NOTE: Yearly power cost values de rived in Figure Cl are for coefficient of flow C -- 140. They may be converted to yearly power cost values for other coeffi cients of flow by means of the following multiplying factors: 1.15 for C = 130 1.34 for C -- 120 1.57 for C= 110 1.86 for C= 100 2.26 for C = 90 2.83 for C = 80 4.82 for C = 60 Diameters derived from Figure Cl are for coefficient of flow C = 140. These may be converted to other diameters for other coefficients of How by means of the fol lowing multiplying factors: 1.033 for C = 130 1.063 for C -- 120 1.100 for C= 110 I 142 for C= 100 1.185 for C = 90 1.261 for C = 80 1.365 for C = 60 Applv the following formula to Table Cl. Mhix uble is reprinted b\ permission ol the J nnns-Man ville Sates Corporation trom I heir pubh\j!ii*n "Discounted Cash Flow, Method ot Investmv.-nt Nppraisul Ml m M'' Where r = rate of yield in percent V = number ot years Irom present D erived fro m the Hazen and W illia m s fo rm u la V - 1 318 C R 63S 54 ra le of h o w - 500 g p m 11893 L / m m i, p o w e r co st - $0 0 2 /kW h 48 AWWA C40I-83 a. a o e o(Z) <T5 O 8 0) a oucV>v 0a 1 t0Ort a1; o o. uJ z 1 CTD031662 Figure ( .1 Yearly P ow er Cost to C om pensate fo r F ric tio n Loss o f H ead XSBESTOS-CEMENT DISTRIBUTION PIPE 49 Euimp/t'- When usinga 10 percent rate of yield, an income of S1.00 occurring each year for the next five years has a present worth of S3.791: for the next seven vears. S4.868: for the next 10 vears. S6.145; etc. The present worth (PW) of a regular pattern ot savings in the future is found as follows: Total years of operation--25 Amount of annual savings--S5000.00 PW lactor at 10 percent--9.077 Total present worth ( PW)--$45 385.00 When expenditure, cash income, and life are known, and income is the same each year, the PW factor can be computed by dividing expenditure by annual cash income. Yield can then be determined by looking for the factor on the line for known life in Table Cl. CTD031663 50 AWWA C40I-83 TABLE Cl Present Worth of an Income of $1.00 per Year for the Next N Years Im H 1.0* 19* 2.0* 25* 3.0* 15* 4.0* 4.9* 9.0* Trt X .995 .990 .985 .980 .976 2 1.985 1.970 1.956 1.9L2 1.927 3 2.970 2.9L1 2.912 2.88b 2.856 li 3.950 3.902 3.8SL 3.808 3.762 5 L.926 L.853 b.783 b.713 b.6b6 .971 1.913 2.829 3.717 b.580 .966 1.900 2.802 3.673 b.515 .962 1.886 2.775 3.630 b.L52 .957 1.873 2.7L9 3.588 b.390 .952 1.859 2.723 3.SL6 L.329 1 2 3 b 5 6 5.896 5.795 5.697 5.601 5.508 7 6.862 6.728 6.598 6.L72 6.3h9 8 7.823 7.652 7.L86 7.325 7.170 9 8.779 8.566 8.361 8062 7.971 10 9.730 9.L71 9.222 8.983 8.752 S.bl7 6.230 7.020 7.786 8.530 5.329 6015 6.87b 7.608 8.317 5.2L2 6.002 6.733 7.L35 8.111 5.158 5.893 6.596 7.269 7.913 5.076 5.786 6.L63 7.108 7.722 6 7 8 9 10 n 10.68 10.37 10.07 9.787 9.51b 12 11.62 11.26 10.91 10.58 10.26 13 12.56 12.13 11.73 11.35 10,98 111 13Ji9 13.00 12. Sh 12.11 11.69 15 1L.L2 13.87 13.3b 12.85 12.38 9.253 9.95b 10.6b 11.30 11.9b 9.002 9.663 10.30 10.92 U.S2 8.760 9.385 9.986 10.56 11.12 8.529 9.119 9.683 10.22 10.7b 8.306 8.863 9.39b 9.899 10.38 11 12 13 lb IS 14 15.3L lh.72 lb. 13 13.58 13.06 17 16.26 15.56 lb.91 lb.29 13.71 18 17.17 16 .LO 15.67 lb.99 lb. 35 19 18.08 17.23 16.L3 15.68 lb.98 20 18.99 18.05 17.17 16.35 15.59 12.56 13.17 13.75 lb. 32 lb. 88 12.09 12.65 13.19 13.71 lh.21 11.65 12.17 12.66 13.13 13.59 11.23 11.71 12.16 12.59 13.01 10.8b 11.27 11.65 12.09 12 .b6 16 17 18 19 20 21 19.89 18.86 17.90 17.CE 16.19 22 20.78 19.66 18.62 17.66 16.77 23 21.68 20.L6 19.33 18.29 17.33 21i 22.56 21.2L 20.03 18.91 17.89 25 23.L5 22.02 20.72 19.52 18.L2 15 .b2 15.9b 16.bb 16.9b 17.hi lb.70 1507 15.62 16.06 16.b8 lb.03 1L.L5 lb. 86 15.25 15.62 13.bl 13.78 lb.15 lb. 50 lb. 83 12.82 13.16 13 .b9 13.60 lb. 09 21 22 . 23 2b 25 26 2L.32 22.80 21.L0 20.12 18.95 27 25.20 23.56 22.07 20.71 19. h6 26 26.07 2L.31 22.73 21.28 19.97 29 26.93 25.07 23.38 21.8b 20. L5 30 27.79 25.81 2L.02 22. bO 20.93 31 28.65 26.5h 2L.65 22.9b 21.bO 32 29.50 27.27 25.27 23.b7 21.85 33 30.35 27.99 25.88 23.99 22.29 3!i 31.20 28.70 26. h8 2b.50 22.72 35 32.0L 29. hi 27.08 25.00 23.15 36 32.87 30.11 27.66 25. b9 23.56 37 33.70 30.80 28.2b 25.97 23.96 38 3L.53 31.L9 28.81 26.LL 2b.35 39 35.35 32.16 29.37 26.90 2b.73 hO 36.17 32.ah 29.92 27.36 25.10 LI 36.99 33.50 30. u6 27.30 25. h7 L2 37.80 3L.16 30.99 28.2b 25.82 L3 38.61 3h.81 31.52 28.66 2607 LL 39.hi 35.L6 32.0b 29.08 26.50 LS ho.a 36.09 32.55 29.L9 26.83 L6 hi.00 36.73 33.06 29.89 27 05 L7 hi. 79 37.35 33.55 30.29 27.L7 he L2.58 37.97 3b.Ob 30.67 27.77 LS L3.36 38.59 3b.53 31.05 28.07 50 hii.lh 39.20 35.00 31.L2 28.36 17.88 18.33 18.76 1909 19.60 16.89 17.29 17.67 18.0b 18.39 15.98 16.33 16.66 16.98 17.29 15.15 15. LS 15.7b 16.02 16.29 lb.36 lb. 6b lb.90 15.1b IS.37 26 27 28 29 30 20.00 20.39 20.77 21.13 21.b9 18.7b 19.07 19.39 19.70 20.00 17.59 17.87 18.15 18. hi 18.67 16.5b 16.79 17.02 17.25 17 .L6 15.59 15.80 16.00 16.19 16.37 31 32 33 3h 35 21.83 22.17 22.b9 22.81 23.12 20.29 20.57 20.8b 2100 21.36 18.91 19.1b 19.37 19.58 19.79 17.67 17.86 18.05 18.23 18.bO 16.55 16.71 16.87 17.02 17.16 36 37 38 39 bo 23.10 23.70 23.98 2b.25 2b. S2 21.60 21.8b 22.06 22.28 22.50 19.99 20.19 20.37 20.55 20.72 18.57 18.72 18.87 19.02 19.16 17.29 17. b2 17.55 17.66 17.77 bl b2 L3 bb LS 2b.78 25.03 25.27 25.50 25.73 22.70 22.90 23.09 23.28 23. L6 20.89 21.Qb 21.20 21.3b 21.b8 19.29 19. b2 19.5b 19.65 19.76 17.88 17.98 18.08 18.17 18.26 L6 Jh b7 W L8 h9 50 r CTD031664 rm 5 3% ASBESTOS-CEMENT DISTRIBUTION PIPE 51 TABLE Cl (continued) 4.0% 4.3% 7.0% 7.J% 8.0% 8.9% 9.0% f.9% 10.0% Yw* 1 .916 .913 .939 .935 .930 .926 .922 .917 .913 .909 1 2 1.816 1.833 1.821 1.808 1.796 1.783 1.771 1.759 1.717 1.736'- 2 1 u 2.698 2.673 2.616 2.621 2.6C1 2.577 2.551 2.531 2.509 2.187 3.505 3.165 3.126 3.387 3.319 3-312 3.276 3.210 3.201 3.170 3 1 c 1.270 1.212 1.156 1.100 1.016 3.993 3.911 3.890 3.810 3.791 5 6 1.996 1.917 i.au 1.767 1.691 1.623 U.551 1.186 1.120 1.355 6 7 5.683 5.582 5.185 5.389 S.297 5.206 S.U9 5.033 1.950 1.868 7 e 6.335 6.210 6.089 5.971 5.357 5.717 5.639 5.535 5.133 5.335 8 9 6.952 6.802 6.656 6.515 6.379 6.217 6.U9 5.995 5.875 5.759 9 10 7.538 7.360 7.189 7.021 6.861 6.710 6.561 6.118 6.279 6.115 10 n 8.093 7.887 7.689 7.199 7.315 7.139 6.969 6.805 6.617 6.195 U 12 8.619 8.381 3.159 7.913 7.735 7.536 7.315 7.161 6.981 6.811 12 13 9.117 6.853 8.600 8.358 8.126 7.901 7.691 7.187 7.291 7.103 13 11 9.590 9.295 9.011 8.715 8.189 8.211 8.010 7.786 7.572 7.367 11 15 10.01 9.712 9.103 9.108 8.827 8.559 8.301 8.061 7.828 7.606 IS 16 10.16 10.11 9.768 9.117 9.112 8.851 8.575 8.313 8.062 7.821 16 17 10.87 10.18 10.11 9.763 9.131 9.122 8.825 8.511 8.276 8.022 17 18 11.25 10.83 10.13 10.06 9.706 9.372 9.055 8.756 8.171 8.201 18 19 11.61 11.16 10.71 10.31 9.959 9.601 9.268 8.950 8.650 8.365 19 20 11.95 11.17 11.02 10.59 10.19 9.818 9.163 9.129 8.812 8.511 20 21 12.28 11.76 11.29 10.81 10.11 10.02 9.611 9.292 8.961 8.619 21 22 12.58 12.01 U.51 11.06 10.62 10.20 9.810 9.112 9.097 8.772 22 23 12.88 12.30 11.77 11.27 10.81 10.37 9.963 9.S80 9.221 8.883 23 21 13.15 12.55 11.99 11.17 10.98 10.53 10.10 9.707 9.331 8.985 21 25 13 .U 12.78 12.20 11.65 11.15 10.68 10.23 9.823 9.138 9.07? 25 26 13.66 13.00 12.39 11.83 11.30 10.81 10.35 9.929 9.532 9.161 26 27 13.90 13.21 12.58 11.99 11.11 10.91 10.17 10.03 9.618 9.237 27 28 11.12 13.11 12.75 12.11 11.57 11.05 10.57 10.12 9.697 9.307 28 29 11.33 13.59 12.91 12.28 11.70 11.16 10.66 10.20 9.769 9.370 29 30 11.53 13.77 13.06 12.11 11.31 11.26 10.75 10.27 9.835 9.127 30 31 11.72 13.93 13.20 12.53 11.92 11.35 10.83 10.31 9.895 9.179 31 32 11.90 11.08 13.33 12.65 12.02 U.ll 10.90 10.11 9.950 9.526 32 33 15.08 11.23 13.16 12.75 12.11 U.51 10.97 10.16 10.00 9.569 33 31 15.21 11.37 13.58 12.85 12.19 U.59 11.03 10.52 10.05 9.609 31 35 15.39 11.50 13-69 12.95 12.27 U.66 11.09 10.57 10.09 9.611 35 36 15.51 11.62 13.79 13.01 12.35 11.72 U.ll 10.61 10.13 9.677 36 37 15.67 11.71 13.89 13.12 12.12 11.78 U.19 10.65 10.16 9.706 37 38 15.81 11.85 13.98 13.19 12.18 U.83 U.21 10.69 10.19 9.733 38 39 15.93 11.95 11.07 13.27 12.51 11.88 U.28 10.73 10.22 9.757 39 10 16.05 15.05 11.15 13.33 12.59 11.93 11.32 10.76 10.25 9.779 10 u 16.16 15.11 11.22 13.39 12.65 11.97 U.35 10.79 10.27 9-7T9 11 U2 16.26 15.23 11.29 13.15 12.69 12.01 U.38 10.81 10.29 9.817 12 13 16.36 15.31 11.36 13.51 12.71 12.01 U.ll 10.81 10.31 9.831 13 tit 16.16 15.38 11.12 13.56 12.78 12.08 U.ll 10.86 10.33 9.819 11 u5 16.55 15.16 11.18 13.61 12.82 12.11 U.17 10.88 10.35 9.863 IS 16 16.63 15.52 1U. 51 13.65 12.86 12.11 U.19 10.90 10.36 9.875 16 17 18 16.71 15.59 11.59 13.69 12.89 12.16 U.51 10.92 10.38 9.887 17 16.79 15.65 11.61 13.73 12.92 12.19 U.53 10.93 10.39 9.897 18 19 50 16.86 15.71 11.68 13.77 12.95 12.21 U.55 10.95 10.10 9.906 19 16.93 15.76 11.73 13.80 12.98 12.23 U.57 10.96 10.11 9.915 50 CTD031665 52 AWWA C40I-83 TABLE Cl (continued) Yiart 10.5% 11.0* 11.9* 120* 119* 13.0* 13.S* 14. OX 14.5% 15.0* Ywi 1 .905 .901 .897 .893 .889 2 1.726 1.713 1.701 1.690 1.679 3 2.665 2.666 2.623 2.602 2.381 6 3-136 3.102 3.070 3.037 3.006 5 3.763 3.696 3.650 3.605 3.561 6 6.292 6.231 6.170 6.111 6.056 7 6.789 6.712 6.637 6.566 6.692 8 5.239 5.166 5.056 6.968 6.882 9 5.666 5.537 5.631 5.328 5.228 10 6.015 5.889 5.768 5.650 5.536 .805 1.668 2.361 2.976 3.517 .881 1.657 2.3a 2.966 3.675 .877 1.667 2.322 2.916 3.633 .873 1.636 2.302 2.886 3.392 .870 1.626 2.283 2.855 3.352 3.998 6.623 6.799 5.132 5.626 3.9a 6.355 6.718 5.038 5.320 3.889 6.288 6.639 6.966 5.216 3.836 6.226 6.562 6.858 5.116 3.786 6.160 6.687 6.772 5.019 1 2 3 6 5 6 7 a 9 10 11 6.368 6.207 6.070 5.938 5.810 12 6.650 6.692 6.361 6.196 6.053 13 6.923 6.750 6.583 6.626 6.270 16 7.170 6.982 6.801 6.628 6.662 15 7.396 7.191 6.997 6.811 6.633 16 7.596 7.379 7.172 6.976 6.785 17 7.779 7.569 7.329 7.120 6.920 18 7.965 7.702 7.670 7.250 7.060 19 8.095 7.839 7.596 7.366 7.167 20 8.231 7.963 7.710 7.669 7.2^ 21 8.356 6.075 7.811 7.562 7.326 22 8.665 8.176 7.903 7.665 7.601 23 8.566 8.266 7.986 7.718 7.667 26 8.657 8.366 8.058 7.786 7.526 25 3.739 8.622 8.126 7.863 7.579 5.687 5.918 6.122 6.302 6.662 5.568 5.787 5.979 6.169 6.299 5.653 5.660 5.862 6.002 6.162 S.3a 5.538 5.710 S.861 5.992 5.236 5.621 5.583 5.726 5.867 6.606 6.729 6.860 6.938 7.025 6.631 6.567 6.669 6.739 6.819 6.265 6.373 6.667 6.550 6.623 6.106 6.206 6.296 6.370 6.a7 5.956 6.067 6.128 6.198 6.259 7.102 7.170 7.230 7.283 7.330 6.889 6.951 7.005 7.053 7.095 6.687 6.7a 6.792 6.835 6.873 6.695 6.566 6.590 6.629 6.663 6.312 6.359 6.399 6.636 6.666 11 12 13 16 15 16 17 18 19 20 21 22 23 26 25 J 26 8.816 8.688 8.183 7.896 7.626 27 8.881 8.568 8.236 7.963 7.667 28 8.962 8.602 8.283 7.986 7.706 29 8.997 8.650 8.326 3.022 7.737 30 9.067 8.696 8.366 3.055 7.766 31 9.093 6.733 6.398 8.085 7.792 32 9.136 8.769 8.629 8.112 7.815 33 9.171 8.801 8.656 8.135 7.636 3L 9.206 8.829 8.681 3.157 7.856 35 9.235 8.855 8.503 8.176 7.870 36 9.262 8.879 8.523 8.192 7.835 37 9.287 8.900 8.5a 6.208 7.898 38 9.309 8.919 8.557 8.221 7.909 39 9.330 8.936 8.571 8.233 7.919 60 9-368 8.951 8.536 8.266 7.928 a 9.365 8.965 8.595 8.253 7.936 62 9.380 8.977 8.606 6.262 7.963 63 9.396 8.989 8.615 8.270 7.969 66 9.606 8.999 8.623 8.276 7.955 65 9.617 9.008 8.631 8.283 7.960 66 9.627 9.016 8.637 8.288 7.965 67 9.637 9-026 8.663 8.293 7.968 68 9.665 9-030 8.669 8.297 7.972 69 9.652 9.036 8.656 3.301 7.975 50 9.659 9.062 8.658 8.306 7.978 7.372 7.609 7.6a 7.670 7.696 7.132 7.165 7.196 7.219 7.262 6.906 6.935 6.961 6.983 7.003 6.693 6.718 6.7a 6.761 6.778 6.691 6.516 6.536 6.551 6.566 26 27 28 29 30 7.518 7.538 7.556 7.572 7.586 7.261 7.279 7.296 7.307 7.319 7.020 7.035 7.068 7.060 7.070 6.793 6.306 6.817 6.827 6.836 6.579 6.591 6.600 6.609 6.617 7.598 7.609 7.618 7.627 7.636 7.330 7.339 7.367 7.356 7.361 7.079 7.087 7.096 7.100 7.105 6.866 6.851 6.356 6.861 6.866 6.623 6.629 6.636 6.638 6.662 31 32 33 36 35 36 37 38 39 60 7.6a 7.667 7.652 7.657 7.6a 7.366 7.371 7.375 7.379 7.383 7.110 7.116 7.117 7.120 7.123 6.870 6.873 6.876 6.879 6.881 6.665 6.668 6.650 6.652 6.656 a 62 63 66 65 7.666 7.668 7.671 7.673 7.675 7.386 7.388 7.390 7.392 7.396 7.126 7.128 7.130 7.131 7.133 6.883 6.885 6.836 6.837 6.889 6.656 6.657 6.659 6.660 6.661 66 67 t 68 1 69 50 CTD031666 ASBESTOS-CEMENT DISTRIBUTION PIPE 53 TABLE Cl (continued) 15, J* 16 0% 16. 17.0* 17.5* OX 19.0X 19.J* X.0% Yw 1 .866 .062 .358 .855 .851 2 1.615 1.605 1.595 1.585 1.575 3 2.26a 2.2a6 2.228 2.210 2.192 6 2.826 2.798 2.770 2.763 2.716 5 3.313 3.271 3.236 3.199 3.163 6 3.73a 3.685 3.636 3.589 3.563 7 a.099 a.039 3.980 3.922 3.866 8 a.ais a.3aa a. 27a 6.207 6.162 9 a.688 a.607 a. 527 a.asi 6.376 10 a.92S a. 833 a.7as 6.659 6.575 11 5.130 5.029 a. 931 6.836 6.765 12 5.307 5.197 5.091 6.988 6.889 13 5.a6i 5.3a2 5.228 5.118 5.012 16 5.59a 5.a68 5.366 5.229 5.117 15 5.709 5.575 5.667 5.326 5.206 16 5.806 5.668 5.53a 5.605 5.281 17 5.895 5.7a9 5.609 5.675 5.366 18 5.969 5.818 5.673 5.536 5.601 19 6.03a 5.877 5.728 5.586 5.667 20 6.090 5.929 5.775 5.628 5.687 21 6.139 5.973 5.615 5.665 5.5a 22 6.181 6.011 5.850 5.696 5.550 23 6.217 6.oaa 5.880 5.723 5.576 26 6.2a9 6.073 5.905 5.766 5.595 25 6.276 6.097 5.927 S.766 5.613 .867 1.566 2.176 2.690 3.127 .866 1.556 2.157 2.666 3.092 .860 1.567 2.160 2.639 3.058 .837 1.537 2.123 2.613 3.026 .833 1.528 2.106 2.589 2.991 3.698 3.812 6.078 6.303 6.696 3.653 3.758 6.015 6.232 6.615 3.610 3.706 3.956 6.163 6.339 3.367 3.655 3.895 6.096 6.265 3.326 3.605 3.837 6.031 6.192 6.656 6.793 6.910 5.008 5.092 6.570 6.700 6.810 6.903 6.982 6.686 6.611 6.715 6.802 6.876 6.606 6.523 6.622 6.705 6.776 6.327 6.639 6.533 6.611 6.675 5.162 5.222 5.273 5.316 5.353 5.068 5.106 5.151 5.191 5.226 6.938 6.990 5.033 5.070 S.101 6.832 6.880 6.921 6.956 6.983 6.730 6.775 6.812 6.863 6.870 5.386 5.610 5.632 5.651 5.667 5.252 5.276 5.296 5.313 5.328 5.127 5.169 5.167 5.182 5.195 S.007 5.026 5.Q63 5.057 5.069 6.891 6.909 6.925 6.937 6.968 1 2 3 6 5 6 7 8 9 10 11 12 13 16 15 16 17 18 19 20 21 22 23 26 25 26 6.299 6.118 5.966 5.783 5.628 27 6.320 6.136 5.962 5.798 5.661 28 6.337 6.152 5.976 5.810 5.652 29 6.353 6.166 5.988 5.820 5.661 30 6.366 6.177 5.999 5.829 5.669 31 6.378 6.187 6.007 5.837 5.676 32 6.387 6.196 6.015 5.866 5.681 33 6.396 6.203 6.021 5.869 5.686 3U 6.aoa '6.210 6.027 5.856 5.691 35 6.aio 6.215 6.032 5.858 5.696 36 6.ai6 6.220 6.036 5.862 5.697 37 6.a20 6.22a 6.039 5.865 5.700 38 6.a25 6.228 6.062 5.867 5.702 39 6.a28 6.231 6.015 5.869 5.706 ao 6.U31 6.233 6.067 5.871 5.705 ai 6.636 6.236 6.069 5.873 5.707 a2 6.a36 6.238 6.051 5.876 5.708 U3 5.aj8 6.239 6.052 5.875 5.709 Ivi 6.aao 6.261 6.053 5.876 5.710 as s.aa2 6.2a2 6.056 5.877 5.710 a6 6.aai 6.2ai 6.055 5.878 5.711 ,67 6. i i hi1 6.2aa 6.056 5.879 5.711 ' u8 6.uu5 6.265 6.057 5.879 5.712 69 6.666 6.216 6.057 5.880 5.712 50 6.667 6.216 6.058 5.880 5.712 5.680 5.692 5.502 5.510 5.517 5.360 5.350 5.359 5.366 5.372 5.206 5.215 5.223 5.229 5.235 5.078 5.086 5.093 5.099 5.106 6.956 6.966 6.970 6.975 6.979 26 27 28 29 30 5.523 5.528 5.532 5.536 5.539 5.377 5.382 5.385 5.389 5.391 5.239 5.263 5.266 5.269 5.251 5.108 5.in 5.116 5.116 5.118 6.982 6.985 6.988 6.990 6.992 31 32 33 36 35 5.561 5.563 5.565 5.567 5.568 5.393 5.395 5.397 5.398 5.399 5.253 5.255 5.256 5.257 5.258 5.120 5.121 5.122 5.123 5.126 6.993 6.996 6.995 6.996 6.997 36 37 38 39 60 5.569 5.550 5.551 5.552 5.552 5.600 5.601 5.602 5.602 5.603 5.259 5.260 5.260 5.261 5.261 5.125 5.125 5.126 5.126 5.127 6.997 6.998 6.998 6.998 6.999 61 62 63 66 65 5.553 5.553 5.556 5.556 5.556 5.603 5.606 5.606 5.606 5.606 5.261 5.262 5.262 5.262 5.262 5.127 5.127 5.127 5.127 5.128 6.999 6.999 6.999 6.999 6.999 66 67 68 69 so 54 AWWA C401-83 TABLE Cl (.continued) Yxr> 21* 22* 23* 24* 2 %% 27* 2K 29* 9* Tm 1 .826 .620 .813 .806 .800 2 1.509 1.1*92 1.U71* 1.157 1.11*0 3 2.071; 2.01*2 2.011 1.981 1.952 u 2.51*0 2.1*91* 2.1*1*8 2.101 2.362 5 2.926 2.861* 2.803 2.715 2.689 6 3.22*5 3.167 3.092 3.020 2.951 7 3.508 3.1*16 3.327 3.21*2 3.1cl 8 3.726 3.619 3.518 3.121 3.329 9 3.905 3.786 3.673 3.566 3.163 10 1.051 3.923 3.799 3.682 3.571 11 1.177 L.035 3.902 3.776 3.656 12 1*.278 1*.127 3.985 3.851 3.725 13 U.362 1*.203 1*. 053 3.912 3.780 1U 1.1*32 1*. 265 It. 106 3.962 3-821 15 1*.1*89 L.315 U.153 1.001 3.859 16 1*.536 1*.357 1.189 1.033 3.887 17 It. 576 1*.391 it.219 1.059 3.910 18 1*.606 1*. 1*19 1*.21*3 1.080 3.928 19 1*.635 1*.1*1*2 L.263 1.097 3.912 20 1*.657 It.1*60 It.279 1.110 3.951 21 1*.67S 1*.1*76 1*. 292 1.121 3.963 22 1.690 2*.1*88 L .302 1.130 3.970 23 1*. 703 1*.1*99 1*.311 1.137 3.976 21 1.713 1..507 lt.318 1.11*3 3.9a 25 !*.721 1*-5U 1*.323 1.117 3.985 .791 1.121 1.923 2.320 2.635 .787 1.107 1.896 2.280 2.583 7a 1.392 1.868 2.211 2.532 .775 1.376 1.812 2.203 2.183 .769 1.361 1.816 2.166 2.136 1 2 3 1 5 2.885 3.083 3.21*1 3.366 3.165 2.821 3.009 3.1S6 3.273 3.361 2.759 2.937 3.076 3.181 3.269 2.700 2.868 2.999 3.100 3.178 2.613 2.802 2.925 3.019 3.092 6 7 8 9 10 3.513 3.606 3.656 3.695 3.726 3.137 3.193 3-538 3.573 3.601 3.335 3.387 3.127 3.159 3.183 3.239 3.286 3.322 3.351 3.373 3.117 3.190 3.223 3". 219 3.268 11 12 13 11 15 3.751 3.771 3.786 3.799 3.808 3.623 3.610 3.651 3.661 3.673 3.503 3.518 3.529 3.539 3.516 3.390 3.103 3.113 3.121 3.127 3.283 3.295 3.301 3.311 3.316 16 17 18 19 20 3.816 3.822 3.827 3.831 3.831 3.679 3.681 3.689 3.692 3.691 3.551 3.556 3.559 3.562 3.561 3.132 3.136 3.138 3.111 3.11*2 3.320 3.323 3.325 3.327 3.329 21 22 23 21 25 26 a. 728 1.520 1* .328 1.151 3.988 27 1*. 731* l*.52l* 1*.332 1.151 3.990 28 1.739 1*. 528 1*.335 1.157 3.992 29 U. 71*3 1* .531 1*.337 1.159 3.991 30 1.716 1*. 531* 1*.339 1.160 3.995 31 It.71*9 1.536 1* .31*1 1.161 3.996 32 lt.75l 1*.538 l*.31*2 1.162 3.997 33 1*. 753 1* .539 L .31*3 1.163 3.997 31 l*. 755 l.51*0 1.31*1* 1.161 3.998 35 1*.7S6 i.su 1.315 1.161 3.998 36 1*-757 1*.S1*2 1.315 1.165 3.999 37 lt.758 1*.51*3 1.31*6 1.165 3.999 38 1*.759 1*.51*3 1.316 1.165 3.999 39 1*. 759 1.511 1.32*6 1.166 3.999 1*0 1*. 760 1*.51*1* 1.317 1.166 3.999 u 1*.760 L. 51*1* 1.317 1.166 1.000 1*2 1*.760 1.511 1.317 1.166 1.000 1*3 1*. 761 1*.51*5 1.317 1.166 1.000 11 1*. 761 It.51*5 1.317 1.166 1.000 1*5 1*. 761 l*.51*5 1.317 1.166 1.000 1*6 1.761 1.515 1.318 1.166 1.000 1*7 1*.761 1*.S1*5 1.318 1.166 1.000 1*8 1*.761 1*. 51*5 1.318 1.167 1.000 1*9 1*. 761 1*.51*5 1.318 1.167 1.000 50 lj.762 1*. 51*5 1.318 1.167 1.000 3.837 3.839 3.810 3.811 3.812 3.696 3.698 3.699 3.700 3.701 3.566 3.567 3.568 3.569 3.569 3.111 3.115 3.116 3.11*6 3.117 3.330 3.331 3.331 3.332 3.332 3.813 3.81*1 3.811 3.815 3.81*5 3.701 3.702 3.702 3.703 3.703 3.570 3.570 3.570 3.571 3.571 3.117 3.117 3.118 3.118 3.118 3.332 3.333 3.333 3.333 3.333 3.815 3.815 3.816 3.816 3.81*6 3.703 3.703 3.703 3.703 3.703 3.571 3.571 3.571 3.571 3.571 3.118 3.118 3.118 3.118 3.118 3.333 3.333 3.333 3.333 3.333 3.816 3.816 3.81*6 3.816 3.816 3.703 3.571 3.701 3.571 3.701. 3.571 3.701 3.571 3.701 3.571 3.118 3.118 3.118 3.118 3.118 3.333 3.333 3.333 3.333 3.333 3.816 3.81*6 3.316 3.816 3.816 3.701 3.701 3.701 3.701 3.701 3.571 3.571 3.571 3.571 3.571 3.118 3.118 3.118 3.118 3.118 3.333 3.333 3.333 3.333 3.333 26 27 28 29 30 31 32 33 31 35 36 37 38 39 10 11 12 13 11 15 16 _ 17 A 18 W 19 50 CTD031668 This page intentionally blank. CTD031669 This page intentionally blank. CTD031670 This page intentionally blank. CTD031671 AWWA C40I-83 4 September 1983 Department of Defense Acceptance Notice This nongovernment document was adopted and approved for use by the Department of Defense (DoD) on 4 September 1983. The American Water Works Association has furnished the clearance required by existing regulations. Copies of the document are stocked by DoD Single Stock Point, Naval Publications and Forms Center, Philadelphia, PA 19120. for issue to DoD activities only. Contractors and industry groups must obtain copies from AWWA. 6666 West Quincy Ave., Denver, CO 80235. Title of Document: AWWA Standard Practice for The Selection of Asbestos-Cement Distribution Pipe, 4 in. Through 16 in. (100 mm Through 400 mm), for Water and Other Liquids Date of Specific Issue Adopted: January 30. 1983 Releasing Industry Group: American Water Works Association Custodians: Army--ME Navy--YD Air Force--99 Military Coordinating Activity: Navy--YD Project No. 5630-0103 FSC 5630 IP-I I 5M-4340I-7 83-LL 010031672