Document 6Bx9yVdK8bkjwpxRZ4YJ4dGG9

'JSBBESTOS CEMENT PIPE DESIGN W. INSTALLATION <L American Water Works ?A$soci.^.tion Manual of Water Supply Practi^^ANWA Manual No. Octo'ber 1-/ '1980 CAPCO JEN 0020003 TABLE OF CONTENTS TITLE Asbestos-Cement Pipe Design and Installation American Water Works Association Manual of Water Supply Practice AWWA Manual MXXX Purpose and Sinope Section I Chapter 1 'Chapter 2 Chapter 3 Chapter 4 Chapter 5 General Information AWWA Standards for Asbestos-Cement Pip.e Physical Characteristics of Asbestos-Cement Pipe Uses of Asbestos-Cement Pipe Manufacture of Asbestos-Cement Pipe Resistance to Aggressive Environments Section II Chapter 6 Chapter 7 Chapter 8 Chapter 9 Design Hydraulics External Loads on Asbestos-Cement Pipe Water Hammer and Surge Selection of Asbestos-Cement Distribution and Transmission Pipe Section III Chapter 10 Chapter 11 Chapter 12 Chapter 13 Construction Installation of Asbestos-Cement Pressure Pipe Special Construction Techniques Testing and Inspection Work Practices for Asbestos-Cement Pipe Section IV Chapter 14 Chapter 15 Engineering Data Pipe, Couplings, Fittings Adapter^ Miscellaneous CAPCO JEN 0020004 PURPOSE AND SCOPE The purpose of thi.3 manual is to present the accepted'engineering practice for the design and selection of asbestos-cement'pressure pipe. Further, to present the latest construction techniques and work practices for the proper installation and field testing of asbestos-cement pipe. Also contained in this manual is general information and .product data related to asbestos-cement pipe including AWWA Standards, physical properties, manufacture, behavior in agressive environments, dimensions, fittings, etc. It is the intent of the manual to supply the Engineer or the specifying agency, Contractor, and Water Utilities Director with essentially all the information necessary for their particular needs.. Toward this end, the manual is broken into 15 chapters; each presents specific information or data in a particular area. In this way, the user can turn immediately to the subject of his interest. Nothing in this manual is intended to supercede any portion of any AWWA standard. CAPCO JEN 0020005 SECTION I - GENERAL INFORMATION Chapter 1 AWWA STANDARDS FOR ASBESTOS-CEMENT PIPE A) Summary of AWWA Standards The American Water Works Association has issued a series of standards which cover the use of a3be3tos-cement pressure pipe. These a3bestos-cement pipe standards were years in the making and most have been revised from time to time to keep abreast of changes in the product and the needs of the water works industry. Each standard is based on the consideration and collective judgement and knowledge of the consumer, general interest and producer interest groups comprising the water works community. Individually and in total, these standards provide an excellent vehicle for the efficient design and installation of asbestos-cement pipe in a water system. These AWWA Standards cover all material and physical require ments as well as the selection, installation, and testing of asbestos-cement pressure pipes. They can be included in job specifications by reference alone or together with any supplementary information necessary for a particular job specification. List of AWWA Asbestos-Cement Pipe Standards: Following are the current AWWA Standards for asbestos-cement pressure pipe. Because these standards are continually reviewed and updated, new editions are published periodically. An up-to-date listing of the latest revisions of these standards is available from the American Water Works Association, 666 West Quincy Avenue, Denver, CO 80235. Copies of individual AWWA Asbestos-Cement Pipe Standards can be purhased form AWWA at that address. CAPCO JEN 0020006 J C400 Asbestos-Cement Distribution Pipe 4" Through 16" for Water and Other Liquids'______________________________________ Material Standard for classes 100, 150, & 200 asbestos- cement pressure pipe. Included are Sections on material, design, workmanship, inspection, testing, rejection, marking, and delivery. \ A forward to the standard (not a part of the standard) contains information on aggressive internal and external waters, non-acid and acid soluble sulfates,- and supplementary specifications. C401 The Selection of Asbestos-Cement Distributions Pipe (4" Through 16" for Water and Other Liquids) Standard practice for the selection of class 100, 150, and 200 asbestos-cement pressure pipe. Included are sections on bedding conditions, combined loading theory, hydrostatic pressures, external loads, safety f factors, and selection procedures including selection curves. C402 Asbestos-Cement Transmission Pipe, 18" Through 42" for Water & Other Liquids Material Standard for strength classifications 30, 35, 40, 45, 50, 60, 70, 80 and 90 asbestos-cement pressure pipe. Included are sections on materials, design, workmanship, inspection, testing, rejection, marking, and delivery. A forward to the Standard (not a part of the Standard) contains Information on aggressive internal and external waters, non-acid and soluble sulfate and supplementary specifications. CAPCO JEN 0020007 C403 The Section of Asbestos-Cement Transmission and Feeder Main Pipe Size3 18W Through 42"._____________________ Standard practice for the selection of strength classi fications 30 35, 40, 45, 50, 60, 70, 80, and 90 asbe3tos-cement prq^ture pipe. Included are sections on bedding conditions, combined loading*, theory, external loads, hydrostatic pressure, pipe selection p/eaour including safety factors, and selection curves. Appendices, which are not a part of the Standard, include sections on friction los3 of lead chart,' surge pressure analysis (including air in pipelines) and frictional power requirements. C603 Installation of Asbestos-Cement Pressure Pipe Included are sections on material acceptance, storage and handling, general and detailed work to be performed, pressure and leakage tests, back filling,, and distribution. B) History of AWWA Asbestos-Cement Pipe Standards Asbestos-cement pipe consisting of an intimate mixture of Portland cement and asbestos fibers was introduced in the North American market in 1929 following usage in other countries, particularly Italy, since 1913* In the ensuing year's,' Asbestos-cement pipe gained wide usage, and in 1949, AWWA established a committee on standard speci fications for asbestos-cement pipe under the chairmanship of S. M. Clark of Greeley and Hanson, Chicago. The committee developed a standard for asbestos-cement water pipe which was approved by the AWWA Board of Directors as a tentative standard (AWWA C440-53, May 15, 1953)* In 1958, the committee was reactivated as Committee 8340D on Asbestos-Cement Pipe under the Chairmanship of Roy H. Ritter CAPCO JEN 0020008 of Whitman, Requardt and Assocs., Baltimore to review several suggested changes and to recommend revisions to the standard. The committee produced a revised tentative standard adopted by AWWA a3 C400-54T, Jan. 27, 1964, which was advanced to standard without revision July 2, 1965. In 1968, the committee under the chairmanship of F. Gordon Denson of the city of Winnipeg, was reactivated as the Standards Committee on Asbestos-Cement Pipe to review and revise all AWWA standards on asbestos-cement pipe. The committee produced a revised standard approved by the Board of Directors, Jan. 31, 1972, designated as AWWA C400-72. "Asbestos-Cement Pressure Pipe for Water and Other Liquids." In 1972 and 1973, the committee under the chairmanship of Robert S. Bryant of the city of Los Angeles, was reorganized and enlarged to include representation of national organiza r tions having an interest in the scope of the committee and wishing to participate in the work. The reorganized committee reaffirmed C400-72 without revision so that it could be presented to the American National Standards Institute (ANSI) for designation as an American National Standard. In 1975, the committee produced a revised standard approved by the AWWA Board of Directors, Jan. 26, 1975, designated as AWWA C400-75, "Asbestos-Cement Pressure Pipe, 4" Through 24", for Water and Other Liquids." At the same time, a new standard was produced by the committee and approved by the AWWA Board of Directors and deisgnated as AWWA C402-75. "Asbestos-Cement Transmission Pipe, 18" Through 42" for Water and Other Liquids." The asbestos-cement pipe manufacturers had developed a new series of large diameter pipe clasifications designed to give greater freedom for selection to design engineers. This is CAPCO JEN 0020009 of particular significance for large diameter pipeline projects where the savings in material' cost can greatly exceed the increased cost of more detailed design, better control of methods of installation, and provision of surge controls when justified. The standard, AWWA C402-75, was developed to provide the user with a ready reference and material specification for this type of pipe known as transmission pipe. The possibility of confusion between the two 1975 standards C400 and C402- wa3 carefully reviewed by the committee. The result was C400-77 which reduces the sizes covered from 4" through 24" to 4" through 16". C402-77 retains the sizes covered from 18" through 42". This eliminated the overlap in sizes in the two standards. "AWWA Handbook H2", Originally entitled "Standard Practice for the Selection of Asbestos-Cement Water Pipe", was first approved by the AWWA Board of Directors on Jan. 27, 1964. The designation was changed later to, "AWWA C401-64." Originally, it covered sizes 4-36", although the design was primarily based on service conditions generally associated with smaller (4-16") distribution sizes. 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 -velocities generated by open hydrant flow conditions on small diameter lines in distribution systems. It is often difficult to evaluate accurately the magnitude of these surges, and often it is impractical from economy and space standards to control the surge by the use of surge tanks or other devices. For these reasons, a sufficiently high safety factor (4:1) is incorporated in the design of asbestos-cement distribution pipe (4"-l6") to account for the potential surge pressures. CAPCO JEN 0020010 Consequently, it was desirable to revise AWWA CH01-64 so that it would be directly compatible with AWWA C400-77 and to develop a new pipe section standard to be directly- compatible with AWWA C402-77, AWWA C401-77, now entitled the selection of "Asbestos-Cement Distribution Pipe 4"-l6" for Water and Other Liquids", and the standard. "AWWA C403-77, Standard Practice for the Selection of Asbestos-Cement Transmission and Feeder Main Pipe, Sizes 18 in. Through 42 in.", are the result. The AWWA C403-77 design for transmission pipe is based on evaluation of all design conditions including Earth Loads and Liveloads in addition to operating pressure and water hammer. Adequate factors of safety are of course applied to the combination of internal pressures and external loads to which the pipe line will be subjected. However, since the selection procedure is more refined and accurate than for distribution pipe, these safety factors are significantly reduced providing an economical strength classification for a particular service. In 1962, the committee concluded that an installation standard was desirable to bring to the attention of users certain important requirements relating to the inspection, handling, installation, and field testing of asbestos-cement pressure pipe. In 1963, the committee submitted its final draft which received approval as tentative (AWWA C603-64T) Jan. 27, 1964. It was advanced to standard (AWWA C603-65, "Installation of Asbestos-Cement Water Pipe") without revision Aug. 9, 1965. In 1978, the committee changed the title to "Installation of Asbestos-Cement Pressure Pipe" instead of "Asbestos-Cement Water Pipe". That standard now covers asbestos-cement distribution pipe (AWWA C400) and asbestos-cement trans mission pipe (AWWA C402). CAPCO JEN 0020011 In 1978, the AWWA Standards Council asked the committee to consider the preparation of a new AWW manual on asbestoscement pipe. This manual is the result of the combined work of the members of this committee. CAPCO JEN 0020012 Chapter 2 PHYSICAL PROPERTIES OF ASBESTOS-CEMENT PIPE Asbesto3-cement pipe is composed of an intimate mixture of either: . 1) Portland cement or Portland blast furnace slag cement with or without silica 2) Portland pozzolna cement and asbestos fiber Either can be with or without the addition of curing agents.' The pipe is formed under pressure and cured. The finished product is free from organic materials. Asbestos used in the asbestos-cement pipe production is imported from Canada and Africa. Research and Product Development has provided many formulations wherein various amounts and types of fiber yield.the necessary strength for a given product line or strength classification. Since there are many formulations encompassing a fairly broad range, precision controls are strictly adhered to in the weighing, mixing and application procedures. Type I Portland cement is used in manufacturing asbestos-cement pipe. This cement complies with the appropriate ASTM specifications for this type. The cement is subject to full quality control procedures, both at the cement company and at the pipe manufactures quality control laboratory, to assure its uniformity and capacity to meet the strength requirements. Silica is also subject to strict quality control procedures as to percentage of pure silica and fineness. Rubber rings used to seal the joints of asbestos cement pipe are also thoroughly tested and must conform to the requirements of ASTM Standard Specification D1869. CAPCO JEN 0020013 Asbestos cement does not have a yield point as does steel. The stress-strain curve is a straight line practically to ultimate load with only a very slight hook at the top (see Figure 1). Figure 1, Typical Stress Strain Curve for Asbestos-Cement Pipe The curve is similar in configuration for both tension and compression. However, in magnitude, the Ultimate Compressive Stress is almost three times the Ultimate Tensile Stress (8,000 PSI vs 3,000 PSI). As might be expected, the configuration of the stress strain curve for concrete in compression* is somewhat similar to asbestos-cement; however, it tends to hook right from the beginning as indicated in Figure I. The stress strain curves for cast iron and aluminum also follow the same pattern as psbestos.-cement and concrete. Curves such as these (with essentially no yield point) are repre sentative of what are sometimes referred to as "brittle material". Failure of the material in laboratory tensile tests The Ultimate Tensile strength of concrete is very low in design and is assumed to have zero. CAPCO JEN 0020014 occurs without visible warning at the ultimate tensile stress. However, the term brittle, used in this sense, is not to imply that the material is lacking in tensile or compressive strength but is used to define a class of materials with certain stress strain characteristics as opposed to ductile materials, such as structural steel whose stress-strain characteristics include a yield point. There is no stress regreAon with time for asbestso-ceraent as . A there is with some plastic.: mat 9ria3r used in pipe materials.' If a test specimen of asbe3tos-cement is stressed to within a few percent of its ultimate stress and held at-that stress, it will stay intact indefinitely. There is no loss of the ability of asbestos-cement to maintain strength. Many plastic materials used in piping will lose 30-50? of their ability to hold a stress close to ultimate over time. Plastic Assuming Stress at Zero Time is Close to Ultimate. Figure 2 indicates the relationship of stress vs time for asbestos-cement, and plastic. Reinforced plastics will also demonstrate a similar stress regression. In addition, asbestos-cement in a stressed condition will not creep with time, as is the case with some materials. Further, CAPCO JEN 0020015 J there is considerable evidence, based on actual performance, that asbestos-cement stressed in a cyclical manner will perform far better than most plastics. This would indicate that the fatique characteristics of asbe3tos-cement are excellent when compared with most plastics. The physical properties of asbestos-cement pipe and rubber rings are presented in tables I and II respectively: TABLE I <' Physical Properties of Asbestos-Cement Pressure Pipe Hydrostatic modules of rupture Size 3"-12" Size 14"-42" Crush modules of rupture (3 edge bearing) Modulus of elasticity f Density Thermal conductivity Thermal coef. of expansion Specific heat Moisture coef. of expansion Hazen Williams' coef. Manning's coef. Axial tensile stress Axial compressive stress Shear Stress Permeability Poissons ratio Dielectric constant C Hardness 3700 PSI 4050 PSI 7000 PSI 7000 PSI 3.4 x 106 PSI 115 lb/ft3 K = 5.5 BTU/Hr/F/sq.ft/in. 4-5 x 10'6 in./in./F 0.27 BTU/lb/F at 212F 1.5 - 2.0 x 10-^ in./in./ % moist. Cont. C = 140 n - 0.010 3.000 PSI 8.000 PSI (full pipe cross section) Laminar 1,000 PSI Across pipe axis 4,000 PSI 0.3 - 0.5 grains/Hr/ft2/ in. thick 0.2 20 (dry) 100 (wet) Rockwell M ID=87 0D=60 CAPCO JEN 0020016 S' ***** * Physical Ka^uiiiwfi of Rubber Rings lor AsbcstnvCfmnrt Pipe i Type of Rubber Ring . q /fC^1 Original Pmpertrcv Tensile strength. mm. MR* (psi): Average of three specimen* tamest individual Elongation. min. 'T: Average nf three specimen* Lowest individual Hardness number* Stress at .KMt r.r elongation, MPa (cm): Mas Min < ompfttsion set. mat. "e t^wtcmpcraiiire flexibility After Oven Aging: Tensile strength, average decrease, mat. % Elongation. average decrease, mat. '> Hardness, average increase, mas, points After Water Aging: Volume change, mat, % Appcrance change After Oil Aging: Tensile strength, average decrease, mat, % Uonptkm. average decrease, mas. % f fattiness, average change, points Volume change, average. *> Nonoil-Rcsivtant OibResistant 12.5(1X00) .150 325 nominal a S l6.0C.KHt) X.4 (1200) 10 no cracks . 15 25 7 12 no surface degradation ... .. ... 9.0(1300) 325 100 nominal s 5 lAOC.KMt) 7.0(1000) 25 k> cracks 20 to 13 12 surface degradation 35 m -1010*2 -1 h) *15 1 Nominal hardness shall be from JO to 60 as specified by the pipe manufacturer. See ASTM Standard Specification D1869 Entitled "Rubber Ring5 for Asbestos-Cement Pipe" for Methods of Test. To determine the actual maximum stress in a pipe wall for a given pipe for either hydrostatic or crush loads, the following formulas may be used. Hydrostatic Stress (OD2 + ID2) S = P ------ 5---------- 5-- (OD^ - ID ; Crush Stress (3 edge'bearing") W (OD + ID) -S- = .159 ---------------------- ? (OD - ID ) Where: S = Stress in pipe wall - PSI OD = Outside diameter of pipe - inches ID = Inside diameter of pipe - inches P = Hydrostatic pressure in pipe - PSI W = Crush load in 3 edge bearing on one foot length of pipe - lbs. CAPCO JEN 0020017 J Chapter 3 USES OF ASP"STOS CEMENT PIPE Asbe3to3-cement pipe serves a wide variety of purposes in both the pressure and non-pressure pipe areas. Its size availability (4" - 42") further enhances the divergence of the applications in which it is found. These uses include the following: 1) Distribution Pipe (4" - 16"). When manufactured and tested in accordance with AWWA Standard C400 and designed in accordance with C401. 2) Transmission Pipe (18" - 42"). When manufactured and tested in accordance with AWWA Standard C402 and designed in accordance wth C403- 3) Main line gravity sewer pipe (8" - 42"). 4) Building sewer pipe (4" - 6"). 5) Force main sewer pipe, all sizes. 6) Storm drain pipe, all sizes. 7) Under drain pipe (perforated pipe) 4" - 12". 8) Agricultural irrigation pipe, all sizes. 9) Turf irrigation pipe (lawns, golf courses, etc.) 4" - 16". 10) Well casing pipe (water wells as well as saltwater and sewage injection wells) - All sizes. 11) Electrical and telephone duct (for direct burial as well as concrete incasement) - 4" - 6". 12) Industrial services (both pressure and sewer - where the corrosion resistance of the pipe is adequate to handle aggressive materials flowing in the line - see Chapter 5 which covers resistance to aggressive environments) - all sizes. 13) Air Carrying Services (Ducts for air conditioning or heating service; either buried below the building slab on overhead) - all sizes. 14) Bridge crossing, all sizes. 15) Under water crossing, all sizes. 16) Vacuum service, all sizes. CAPCO JEN 0020018 J The wide range of strengths and size available permit asbestoscement pipe to be designed for any but the most unusual conditions of service. r L CAPCO JEN 0020019 Chapter 4 MANUFACTURE & QUALITY CONTROL TESTING OF ASBESTOS-CEMENT PIPE The asbesto3 cement industry had it3 beginning in Austria in the 1890*3. Ludwig Hatschek conceived the idea of combining asbestos with Portland cement and water to create a new building material, asbestos-cement. He also developed a machine to produce asbestos cement sheets. In this process, a flat sheet was manufactured by rolling a continuous film of asbestos-cement on to a fixed metal cylinder until the desired thickness was achieved. The material was then cut, peeled off the cylinder and laid out flat and allowed to curve into a rigid sheet. This material met with widespread acceptance in Europe and a patent was registered in varied countries. The first pipe was manufactured by hand from uncured asbestoscement sheets. The sheets were rolled into a cylindered shape and welded along their length. These pipes were obviously not capable of with standing pressure. The process for manufacturing a seamless asbestos-cement pipe that could withstand pressure was developed in Italy by Mazza. He substituted for the fixed cylinder^with-drawable cylinder which is called a mandrel. It was 'then possible to remove this mandwel and the pipe which was formed around it. Today, pipe is made using this basic principle; Although, of course, numerous improvements and modifications have been made in the process. Asbestos-cement pipe was first manufactured in the United States in 1930. A Mazza type pipe machine was purchased in Italy, shipped to the United States, and assembled at a midwestern location. CAPCO JEN 0020020 Manufacture of Asbestos-Cement Pipe presently, in the United States, all pressure pipe is manufactured in accordance with AWWA Standard Specifications. The following outlines the basic steps in the manufacture of asbestos-cement pipe. The blending of different grades and percentages of grades of asbestos fiber is an important and integral part of each manufacturer's production process and will differ from manufacturer to manufacturer, plant to plant, and even product to product. FIGURE 3 Typical Flow Diagram for the Manufacture and Quality Control Testing of Asbestos-Cement Pipe l CAPCO JEN 0020021 The flow diagram presented in Figure 3 outlines a typical process flow of an asbestos-cement pipe manufacturing facility. The cement, asbestos, and silica are initially processed by various methods depending on individual manufacturing procedures. This processing usually includes extremely fine grinding of the silica and "opening up" of the fiber clumps. The asbestos fibers are then throughly blended in a mixer Cl). All the materials are then weighed out in the correct proportions using automatic precision scales and thoroughly dry mixed (2). When the complete dispersion of fibers, cement, and silica has been accomplished in the dry mixer, the material is then transported by conveying methods to a location where water (3) is added to form a homogeneous mixture (slurry). This slurry is transferred by a pump to the main vat (4). A mesh cylinder mold, half submerged in the slurry, rotates in the main vat. A continuous felt band moves at a tangent to this mesh cylinder mold. The cylinder, as it turns, is coated with a thin film of asbestos-cement paste which is deposited on the continuous felt. The excess water drains through the mesh of the cylinder mold into the vat. The continuous felt with the film of asbestoscement paste passes over suction boxes (5) where the excess water still held in the paste is removed. The paste is now prepared to form pipe. The paste then comes in contact with a rotating polished steel mandrel (6). The paste, brought by the felt, continues to wrap itself around the steel mandrel, lamination upon 3.amination, until the desired pipe wall thickness is reached. As the laminations roll on, hydraulic pressure is being applied by the top press section (7) compressing the preceding laminations and squeezing out excess water. CAPCO JEN 0020022 Upon reaching the desired wall thickness, the mandrel with the newly made pipe encasing it is removed and another mandrel is transferred in to repeat the process. The completed pipe and mandrel are conveyed to a loosening area (8). Here the mandrel is separated from the pipe by one of several means. The mandrel is pulled out of the pipe at the mandrel puller station (9) and returned to the pipe machine for another forming cycle. The completed pipe continues on through the moist heat tunnel (10) where initial curing begins. The pipes are transferred to curing trays (11) and placed in autoclaves for high pressure steam curing. High pressure steam chemically combines the free lime found in cement products with the silica forming calcium silicates. This high pressure steam curing process permits a reasonably short curing cycle time to achieve maximum strength and also lends additional chemical resistance to the finished product. After the curing cycle is complete, the pipes are removed from the autoclaves and cooled. They are then transported to the finishing lathes (13) where the ends are trimmed and machined to precise dimensions in accordance with the manufacturer's specifi cation, and AWWA standard specifications. The quality of this end machining is important because it includes the sealing surface which is necessary to assure a water tight joint. The couplings used to join and seal the pipe are made from extra thick pipe stock. The stock is cut to the proper length and then machined on the inside diameter to the precise dimensions. This machining includes two grooves which hold rubber rings. These rubber rings provide the seal between pipe and coupling. At this stage, the manufactured and machined pipe and couplings are ready for the final quality control tests. CAPCO JEN 0020023 J QUALITY CONTROL TESTING OF ASBESTOS-CEMENT PIPE Quality control testing of asbestos cement pipe is a continuous process. Tests are performed on raw materials as well as the finished product. In addition, monitoring of the pipe manufacturing process variables is continually in progress. Checking and testing is done to assure that the finished product meets the manufacturer's own finished product specifictions as well as the testing required for AWWA standard specifications C400 and C402. Following are the tests required by C400 -and C402: Hydrostatic Tests Every length of pipe and every coupling is hydrostatically proof tested (14) to an internal pressure shown in Tables 1 & 2. Required Hydrostatic Test Pressure TABLE 1 TABLE 2 AWWA C401 - Distribution Pi21 AWWA C402 - Transmission Pioe ClassiProof Test-PSI jop Test -PSI iClass [Proof Test-PSI [Lot Test-PSI 100 ! 150 | 200 | 11 11 11 1t 11 11 350 525 700 11 400 11 600 11 300 11 11 11 ! 30 ! 35 i 40 J 45 i 50 I 60 i i ! i i ! 1 ` i 70 ! t1 i 80 j 11 i 90 ! 225 263 300 338 375 450 525 600 675 11 300 tt 350 11 400 1I 450 11 500 1& 600 11 700 11 800 11 900 Proof Test Air in the pipe is expelled and the water pressure is increased at a uniform rate of not less then 100 PSI per second. The test ( CAPCO JEN 0020024- pressure, as shown in the tables under "Proof Test" is maintained for a minimum of 5 seconds. Any pipe length or coupling showing leakage, sweating or other defect i3 rejected. Lot Test A lot is defined a3 all pipe of any one class, type, and size manufactured on any one machine in 24 hours but not to exceed 300 lengths. The lot te3t procedure is different for transmission pipe than for distribution pipe. For distribution pipe, one standard length of pipe from each lot that has passed the hydrostatic proof test is hydrostatically tested to the pressure as shown in Table 1 under "lot test" in the same way as described under "proof test" above. After this, the pipe is reproof tested. For transmission pipe, a one foot or longer sample is cut from the unmachined portion of a length of pipe from each lot that has passed the proof test. This sample is hydrostatically tested to pressures as shown in Table 2 under "lot test" in the same way as described under "proof test" above except the test pressure need not be held for 5 seconds. Flexure Test This test is performed on 4, 6, and 8" pipe only, and conse quently, is only for distribution 'pipe (C400). Each length of pipe of these sizes more than 9-5 feet long is tested in flexure for a minimum of 5 seconds (15). The supports are 9f apart (at the manufacturer's option, lengths greater than 12-5' may be tested on a 12' span at 75% of the load shown in Table 3). The total load is divided equally and applied at the third points as shown in Figure 1. The load is applied at a minimum rate of 200 lb. per second and the total load, as shown in Table 3, is maintained for a minimum of 5 seconds. CAPCO JEN 0020025 Table 3 Figure 1 Flexural Load Tests Total Applied Load-lbs. Diam.-in.jClas3 100 Class 150 Class 200 1200 2800 5330 r it tt 1420 3700 7600 1870 4900 10130 There are two additional tests required by C400 and C402 that are performed separately in a laboratory and not as part of the automated finishing line. These are: Crushing Test This test is performed on one 1 long sample from each 300 lengths of pipe. This test is frequently referred to as the "3 edge bearing test". A diagram of the test assembly is shown in Figure 2. Tig.X Crashing Tost Assembly The two lower bearings in Figure 2 are usually two wood strips with the interior top edge round to a radius of approximately 0.5". They are 1 inch/ft. of internal pipe diameter apart (but not less than 1"). The upper bearing is a rigid wooden block. All bearings extended the full length of the 12" Sample. CAPCO JEN 0020026 After 75% of the load specified in Table H & 5 has been reached, the loading continues at about 2,000 lb. per minute. The sample must meet the specified loads. Table 4 Required 3 Edge Bearing Crush Loads - lb./ft. AWWA C400 - Distribution Pipe ftp* Sin 4 6 8 10 12 14 16 Qua 100 4,100 4,000 4,000 4,400 3.200 5.200 5,800 CUm 150 5,400 5,400 S.SOO 7,000 7.600 8.600 9,200 CUm 200 8.700 9,000 9,300 11,000 11,800 13,500 15,400 Table 5 Required 3 Edge Bearing Crush Loads - lb/ft. AWWA C402 - Transmission Pipe Pipe Sin in. ~ 50 18 2 500 20 2 500 21 2 500 24 2 800 27 3 500 30 3 5(a) 33 3 500 36 4 000 4 200 42 4 3WJ 55 3000 3 500 3 500 3 800 4 200 4 500 5 000 5 000 5 300 5 700 40 4 000 4 500 4 500 5 000 5 500 6 000 6 500 7 000 7 500 8000 Gasification 45 5" 000 5 500 S 800 6 200 7 000 7 500 8 000 9 000 9 700 10 500 50 6 50(7 7 100 7 300 8 100 8 800 9 700 10 500 11 200 12 000 13000 60 8 300 9 500 9 700 11 000 12 500 13 500 14 500 16 000 17 200 18 500 70 11000 12 000 12 500 15 000 16 500 18 000 19 500 21000 22 500 24 000 SO 14 000 15 000 16 000 19 000 20 500 22 500 24 500 26000 28 000 30 000 90 IS 000 20 000 21 000 24 000 27 000 30 000 33 000 36 000 39 000 42 000 c CAPCO JEN 0020027 Te3t for Uncombined Calcium Hydroxide The manufacturer is required to perform this test a3 often as necessary to ensure that the product complies with the require ments for Type II pipe. Type II pipe requires one percent or less of uncombined Calcium Hydroxide. (There is no requirement for Type I pipe). See either C400 or C402 Sections 5.4 for test method and calculations. Manufacturers Inspections At the finishing end, numerous checks are made by the manufac turer's quality control inspectors. All pipe is checked for dimensional correctness to ensure that all tolerances are met. If a coupling is belled on the pipe at the finishing end, a check is made to ensure that the rubber sealing ring is seated properly. In addition, each pipe is checked for any visual imperfections. Following finishing and testing, the pipes are packaged (17) in units specified by individual manufacturers and either placed in inventory or shipped immediately. CAPCO JEN 0020028 Chapter 5 RESISTANCE TO AGGRESIVE ENVIRONMENTS The effectiveness of any piping system is dependent on sound engineering design of all component parts in the system taking into account all of the variables involved. Proper installation of the system using the most up to date construction techniques is also essential to the serviceability of the system. The resistance of all parts of a piping system to aggressive environments is a significant factor in the long term effectiveness and serviceability and is therefore important in design and installation considerations. The economic impact of corrosion of pipelines runs into the hundred of millions of dollars- annually because of required repairs and replacement. An entire branch of engineering is devoted to the understanding, prevention, and control of corrosion. Corrosion engineers are frequently consulted in the initial stages of pipeline design to ensure that potential damage to the life and serviceability of the pipeline from corrosion is minimized. Asbestos-cement pipe is generally very resistant to aggressive environments. However, its behavior, as well as the behavior of other piping materials to various aggressive environments, should be known to all parties involved in the design, installation and operation of pipelined The term ''corrosion" is most commonly associated with the attack of metals by certain aggressive environments. Corrosion in this sense is a/i electrochemical process. The two primary types of OAPOO JEN 0020029 electrochemical corrosion are galvanic and electrolytic corrosion. These are characterized by the formation of electro lytic cells with areas of differing electrical potential forming. There are many excellent discussions of electrolytic corrosion in the liteature and the reader is referred to these for a complete review of the principles and mechanics of corrosion. Asbestos-cement pipes are non-metallic and.are therefore not subject to electro chemical corrosion. However non metallic' materials can be subject to chemical corrosion. Generally, non- metallic materials are attacked only by certain definite chemical agents under specific conditions and am are usually resistant to the action of such mild corrosion media such as water, soils, and the atmosphere. \ The Portland cement in asbestos-cement pipe can be affected by chemical corrosion in severe aggressive environments. Under such conditions, the environment in question should be controlled by some standard means to prevent deterioration of the cement. Dimensional and chemical stability of asbestos-cement pipe is achieved through curing. This curing is one of two types as follows: 1. Type I asbestos-cement pipe is normal cured for about 28 days at room temperature under either moist atmosphere on water immersed conditions. 2. Type II asbestos-cement pipe is cured in an autoclave under conditions of high pressure steam at temperatures of 325 - 385 F. All asbestos-cement pipe manufactured is the United States is Type II. Under these curing conditions of high pressure and high temperature steam, the finely ground silica^ becomes soluble and reacts with the free lime liberated by the Portland cement during hydration. The product of the reaction is a calcium silicate CAPCO JEN 0020030 r hydrate that is much more resistant to sulfate attack then the free line it replaces. Autocla' 'ng produces a product that ' contains les3 than 1% free lime and is consequently a more corrosion resistant asbestos-cement pipe than normal cured pipe. The three types of chemical corrosion that may occur with cement products are listed in Table 6. Type ` Acids (soils) 2) Sulfates (soil J and water) Leaching Nature of Attack Dissolves the lime of the hydrated cement. Chemical reaction with free lime In the hydra tion process. Volume Increase. r~ Solvent action of Soft water on the free lime and other calcium com pounds. Table 6 - Types of Chemical Corrosion on Cement Products. A brief discussion of the three types of corrosion follows: 1. Acid soils react with the silicates formed causing some alteration. The degree of alteration depends on the type and amount of acid present in the soil. Sulfuric acid is usually the only strong acid found in soils. Sulfuric acid in contact with asbestos-cement produces salt products which are only partially soluble in water, so the balance is made up of insoluble salts which remain in the area where they were formed. The presence of these insoluble salts slow the rate of attack. The random matrix of asbestos fibers also tends to hold the reaction products in place. In almost all acid soil environments, autoclave cured asbestos-cement pipe will provide chemical resistance equal to, and in most cases, superior to the chemical resistance of normal cured A/C or concrete pipe. v CAPCO JEN 0020031 2. For sulfate soils, the autoclave cured A/C pipe shows a significant superiority to the normal cured products. Normal cured A/C pipe will expand 200 to 250 percent when exposed to sulfuric acid. This is due to the free lime available. The autoclave cured A/C with less than 1 percent free lime does not have this volume increase. 3. Leaching is the process by which soft water reacts and chemically combines with the calcium and magnesium compounds in its environment. Since all cement products have a high calcium content, there is a tendency for soft water to leach calcium from the cement products. Since ground water tends to pick up the calcium ions from the soil, this leaching action is not much of a problem from ground water. Pipe for Water Service The following criteria are presented for determining the type of pipe (I or II) to be used under various soil and water condi tions.- Each condition should be considered separately even though each may exist in combination with others. These criteria are based on exposures within the temperature range of 40-80F (5-28C). For exposure of pipe to temperatures beyond these limits, consult the manufacturer. The criteria are referenced as: . 1. Internal Water (Table 7). 2. External Water (Table 8). 3. Nonacid Soluble Sulfates - Internal and External (Table 9). 4. Acid Soluble Sulfates - Internal and External Internal Water - The type (I or II) of asbesots-cement pipe suitable for use in a waterline is related to the aggressivenes of the water transported. See Table 7 and the following definition of aggressive water. CAPCO JEN 0020032 Table 7 Aibeitos-Cement Tip* Type Recommended for Internal Water Attretstveness IAnCtefmrnsaWl WeftaCteft*r Kfrnmmendeil Pu* Type* Highly aggressive Moderately aggressive Nonaggressive t ir 1 and II L Aggressiveness of water is defined as follows: a. Highly aggressive: pH + log (AH) < 10.0 b. Moderately aggressive: pH + log (AH) = 10.0-11.9 c. Nonaggressive: pH + log (AH) > 12.0 Where pH = Index of acidity (or alkalinity) of the water-standard pH units A = Total alkalinity - ppm (mg/1) as CaCO^ H = Calcium hardness - ppm (mg/1) as CaCO^ It should be recognized that water that has a pH t log (AH) less than or equal to 10 is an extremely'aggressive water and would be very corrosive to almost all materials found in a typical water system, including the plumbing in consumers' homes. Such waters should be treated to increase pH or hardness to protect the entire network of materials making up the system. If such water treatment is not undertaken, the manufacturer of each item used in the water system should be consulted for recommendations regarding the use of his product in an extremely corrosive environment. CAPCO JEN 0020033 (Note: The expressin pH + log (AH) is a modification of the Langlier Index. It ha3 been prepared so that the aggressive ness of the water can be determined easily. A reasonable comparison of the two would be as indicted below.) Highly Aggressive Water Moderately Aggressive Water Nonaggre3ive Water pH + log (AH) 10.0 10.0-11.9 12.0 Langlier Index - 2.0 -2.0 to -0.1 0 External Water - The aggressiveness of external water (water within the soil environment) is related to the suitable type (I or II) of pipe in Table 8. The guidelines for the use of asbestos-cement pipe in nonsulfate acidic soils are based upon minimum pH factors alone. Asbestos-cement pipe may or may not perform satisfactorily in acidic soil environments that have pH values below those listed in Table 8. To determine the suitability of asbestos-cement pipe in soils having lower pH values, each situation should be evaluated individually and take into consideration all aspects of soil environment that effect asbestos-cement pipe. Table 8 Aggressiveness of Nonsulfate Acidic Soils to Asbestos-Cement Pipe Water Conditions Within (tie Soil Environment Minimum pH of Acidic Soils When Usinc Asbestos-Cement Pipe * ' Type r Type II Essentially quiescent Mildly fluctuating Rapidly moving or grossly cyclic 5.0 5.5 6.3 4.0 5.0 5.5 Nonacid soluble sulfates - internal and external. Aggressivenes of nonacid (pH _> 7.0) soluble sulfates in water and soils is related to the suitable type (I or II) of asbestoscement pipe in Table 9. CAPCO JEN 0020034- Sulfate aggressiveness in water and soil can be classified as follows: Sulfate Aggressiveness Classification foonaggressive Mildly agressive Moderately agressive Highly aggressive Water Soil Water Soluble Water Soluble Neutral Sulfates-ppm SO ^ Sulfates-ppra S0^ lo and less 1.000 and less 150 - 1,500 1,000 - 2,000 1,500 - 10,000 2.000 - 20,000 10,000 and greater 20,000 and greater Table 9 Asbestos-Cement Pipe Type-Designation Chemical Resistance to Nonacid (pH TM 7.0) Soluble Sulfates in Water and Soils Typ Di,nation I* II Chemical Resistance to Nonacid Sotuhle Sulfates in Water anil Soils Will be attacked in various degrees by alt but the nonaggressive levels of sulfate concentrations in waters and soils- Resistant to all levels of soluble sulfates. k *Tbe guideline criteria for sulfate resistance of Type I pipe were taken from the Concrete itannot. Sth edition Bureau of Reclamation, H74. Sulfate resistance here applies to all soluble sulfates resardless of the cation. Acid Soluble Sulfates - internal and external - Aggressiveness of acid (pH 7.0) soluble sulfate waters and soils to asbestoscement pipe must be evaluated independently. Acid sulfate soils a'nd waters', whether the "acid is inorganic or organic, must be evaluated independently of the criteria and guidelines set forth above and must take into consideration soil permeability and other factors. Consult the manufacturer for guidance. CAPCO JEN 0020035 Chapter 6 HYDRAULIC DESIGN The determination of pipe size, velocity, and head loss is the starting point of pipeline design. It is at this time that economic decisions are made which will compare present and future flow requirements with available monies from capital investment, maintenance, pumping and future replacement costs. Within these conditions, the optimum size selection is made based upon a flow equation which relates fluid velocity with pipe diameter, pipe flow resistance, pipeline lengths, energy losses and fluid properties. In this chapter, the Hazen-Williams and Darcy-Weisbach flow equations will be presented and their use illustrated with sample problems. Ha'Zen-Williams - The Hazen-Williams flow formula is the most frequently used design approach in the calculation of pressure piping of clean water. The formula is used in a variety of forms as follows: Equation 1. V = 1.318 *CR0,63 S0,54 Where: V = Flow velocity, ft/sec. C = Flow coefficient R = Hydraulic radius, D/4 for pipe flowing full^ ft. S = Hydraulic slope, ft/ft. Equation 2, Q = 0.442D 2.63 0.54 (P1" V Where: Q = Flow rate, GPM D = Pipe internal diameters, inches P1. =?2 gauge pressures, PSI L = Pipe lengths, ft. C = Flow coefficient Equation 3 Q = 0.006756CD2*63 H0,54 CAPCO JEN 0020036 Where: Q s Flow rate, GPM D = Pipe internal diameter inches H = Head loss, ft/1000 ft. C s Flow coefficient Equation 4 Where: M- F = 0.283 85 1.85 TTH7 F = Friction loss, ft. of H^O/IOO^ Q = Flow rate, GPM D = Pipe internal diameter, in. C s Flow coefficient. Equation 1 provides for the direct determination of the flow velocity in a pipe line. Equations 2 & 3 provide for the determination of flow volume in GPM. However, Equation 2 measures pressure drop as the difference between the readings of 2 pressure gauges a distance L apart while Equation 3 expresses the pressure in terms of feet/1,000 feet. Equation 4 permits the direct calculation of friction loss in hydraulic flow. Through many years of observation of asbestos-cement pipe flow in many pipe lines and under wide conditions of actual service, the Hazen-Williams flow coefficient has been conservatively established as C=140. Substituting this value of C=140 into equations 1 through 4, yields simplified formulas for the design of asbestos-cement pipe systems as follows: Equation 5 Equation 6 Equation 7 V '= 184.5(R)*63 (S)0*54 CP, - p2)0*54 Q = 61.9^*------------------ L Q = .9458D2*63 H0*54 CAPCO JEN 0020037 Equation 8 Where: F = .1118 1.85 T757 V = Flow velocity, ft/sec. Q s Flow rate, GPM F s Friction los3, ft of H20/100 ft, R = Hydraulic radiu3, ft. S r Hydraulic slope, ft/ft. D s Pipe internal diameter, in. Pi ?2 = Gauge pressures, PSI L = Pipe length, ft. H = Head loss ft/1,000 ft. For convenience in design, a nomagraph derived from the HazenWilliara3 formula is presented in figure _____ . This chart, which was established for C=140, simplifies the determination of pipe diameter, flow rate, velocity, and friction loss of head for a given set of conditions. In addition, a nomograph for the determination of the horsepower required to overcome friction loss of head is presented in Figure _____ (flow powergraph). This chart is also derived from the Hazen-williams formula and can be used for any "CM valve from 40 to 140. Following are two illustrative problems of pipe diameter selec tion. The first is a gravity flow situation and the friction loss of Head Chart is utilized only. The second problem involves a pumping situation,.and. both the friction loss of Head Chart and the flow powergraph are used. Illustrative Problem 1 The minimum elevation of the surface of a reservoir is 198 feet. An asbestos-cement pipeline (C = 140) is to carry water by grav ity to a city distribution system, a distance of 5 miles. The pressure at the entrance to the distribution system is to be a CAPCO JEN 0020038 minimum of 75 PSI. Design flow is 1,200 gallons per minute. Determine the size of pipe required and the velocity of design flow. Solution: Head from reservoir Head delivered to distribution system. 2.31 x 75 Allowable loss of head Length of line = 5 x 5280 = 26,400 ft. Allowable loss of head per 1,000 ft. (C = 140) = 24/26.4 = 0.91ft. 198 ft. 174 ft. 24 ft. Enter nomograph in Figure 1 on either top or bottom horizontal axis at 0.91 ft. loss in head per 1,000 ft. Go verticaly to intersection of 1,200 gallons/minute. This lies between 14" and 16" diameter pipe. Therefore use 16". This will deliver about 1,360 gpm at a velocity of about 2.2 ft. per second. Illustrated Problem 2 Water is to be pumped from one reservoir to another by means of a Transite transmission line 50,000 ft. long. The lower reservoir is at elevation 100 ft. and the upper at 250 ft. Design flow is to be 1,000 gpm and the velocity is not to exceed 3 ft/sec. Determine a) the size of pipe required, b) the maximum head at the pump, c) the horsepower and annual power cost required to overcome friction only (not elevation difference) and d) the annual power cost to overcome friction in the line if C = 100 (assume power cost = "$.04 per' kwh); ~ Solution: a. Enter nomograph in Figure 1 at 1,000 gal/min. Proceed to intersection at 3 ft./sec. This falls between 10" and 12" diameter pipe. Use 12" pipe. This will give velocity of about 2.8 ft./sec. at design flow and head los of 2.3 ft/1,000 for C=140. CAPCO JEN 0020039 b. Elevation Difference = 250 -100 = 150 feet Friction loss = 50 x 2.3 = 115 feet Max. head at the pump = 265 feet c. Horsepower and power cost to overcome friction: Use nomograph in Figure - 1,000 gpm = 1^440,000 gal/day. Enter nomograph at C = 140, 12" diameter and 1,440,000 gal/day. Find horsepower/1,000 ft. as indicated. This is 0.4 HP/1,000 ft. converting to Kwh = 0.4 ft. x 6,532 = 2,613 Kwh/year/1,000 ft. 2613 x .04 = $104.51/year/1,000 ft. Total power cost/year = 104.51 x 50 = $5,225.50/year/for C=140. d. Repeat procedure for C = 100, 12" diameter and 1,440,000 horsepower/1,000 ft. = 0.7 HP/1,000 ft. 0.7 x 6532 = 4,572 Kwh/yr/1,000 ft., 4572 x #04 = 182.90/yr/1,000 ft. Total power cost for 1 year = $182.90 x 50 = $9,144.8/yr for C=100. CAPCO JEN 0020040