Document NEnm7XgROQNZXanyqodbm6VQg

NATIONAL INSULATION MANUFACTURERS ASSOCIATION MC 422167 8 0049 WV-05809 Mr 422 i 67 # 0050 As even the most faithful servant works better if not taken for granted, thermal Insula tion will serve mote eflWiently and more eco nomically if scrutinized anew each time it is specified. New methods, material, and total costs make these questions imperative: Could your insulation do its job belter? Could you xave more money? The mind-stirring achievements in spsceprobes, astronautics, missiles, and atomies dram atize what is an old story to the insulation engineer: certain processes just won't work without the right kind and the right amount of thermal insulation. With delicate instruments operating in an environment ot extremes of temperature--from liquid oxygen at take-off to the undimmed radiation of the sun in clear space, and the friction of re-entry into our atmosphere--insulation makes it ail possible. Dogs, monkeys--and yes. men--would not sur vive more rhan minutes in space without insulation. Here on earth these two functions of in sulation-process control and personnel pro tection--are joined by a third, saving money, A few hundred dollars more invested In ade quate insulation for a new plant could save many thousands in a few years! Heat energy is becoming more valuable every day. with rising fuel 8nd labor costs. Al though the cost of insuiatton is normally writ ten oil in a relatively short period, it continues to afford savings for the life of the installation, For maximum savings, you need close figuring. Routine repetition of old specifications will get the job done, but a lot of money will be wasted. General or "rule-of-thumb" specifications and tables in catalogs and handbooks should be consulted only as approximate guides to the requirements of the n? job, Each job should he figured separately by the "economic thick ness'' method rtc&nfTterHicd by ihe Insulation Manufacturers Association and dem onstrated in these pages. You may actually need teas insulation and thus save on material cost: or the job may prove to need as little as an extra half-inch that w ill eo&t slightly more but will save many times its cost in a few years, a tew* months--or even immediately, if in addi tion to fuel savings it permits a reduction of capital expenditures for heating or cooling equipment. tic 422167 P 0051 000917 jf S AVE MONEY in insulating to keep heal energy where we want it.not going to waste all along a system, the basic criterion n "Economic Thickness." 7** is the t&ckneM at **hkb the cost of insulation gives best return on your money, considering both operating and capital corn. Whether we're dealing with power generation, a chemical processing plant, refrigeration, or heating anti air conditioning, the economic thickness n that increment beyond which the extra c< of the applied intukikn *ouW oof* weigh the cost of the energy or the equipment it save*. A thought for the future: If yotir calculations p&int to another increment only a little w*y up the curve. specify it now. Fuel and energy costs will continue to rise. CONTROL PROCESSES In many manufacturing processes. especially of chemicals, the Sme temperatures, hoc or eoW, must be controlled within close limits. Without thermal insulation some processes simply would not work: specifications must start wnh the minimum thickness necessary for temperature control. Next enters the factor of economy. How many increments of insulation is it advisable to add to achieve optimum economy? (Of course you may need more insulation for control than for strictly economic reasons.} A recent survey made tor SIMA indicated that process control and ''return on in* vestment" are closely associated in the minds of both production engineers and management and are prcmheai in their thinking when specifying insulation thickness. To keep the two criteru clearl\ revived, a aouml approach to economic thickness h retired. I * MC 422167.0 0055 3 PREVENT CONDENSATION In cold processes and cold storage roams, in air conditioned buddings, and in tniermirrent hoi and cold processes, eon* dentation of atmospheric moisture oq cdd surfaces (sweating) is a constant hazard. Condensation can reduce efficiency of the processes and Che insuteckfl, end it c&b cor rode metals and rat organic materials. Condensation is prevented by insula tion thick enough to prevent the temperature of the surface of the pipes, ducts, equipment, etc. from getting below the dew point of the atmosphere, A vapor barrier is installed over the insuiation to prevent entry of water vapor into the insulation where by diffusion it may tr&vei to some petal in the insulation which may be below the dew point. The vapor bar rier may be of metal in foilor laminated form, plasticdims such as polyethylene, an asphaltie material or a waterproof mastic, usually ap plied with a reinforcing membrane. The in tegrity and continuity of the vapor barrier arecrtietaf. mw V* *Mn-tei ta'tv'atwv itl MNiwfi. n,avr fe> a Cficnvn the , wi:>. ,nd ,4 ** h **.. PROTECT PERSONNEL * ,.r--" <**.**.. . AND EQUIPMENT Provision for safety is necessary if men are to work close to hot equipment and piping; comfort is necessary if their work is to be efficient over an extended period. A safe surface temperature is the primary re quirement when inorfattftf for protection o\ personnel, and, just as where the primary requirement is process control, more insu lation may be used than simple economy would justify. Desired temperatures for spaces sur rounding hot piping owl equipment vary with the industry, the equipment, and the design of the building, but surfaces that might be a hazard to personnel preferably are kept under 110 F and usually under ISO F. In outdoor plants, insulation keeps sensitise instruments and major equipment safe from freezing weather. H is uted siretegtoffy m plants as a file stop. The protective function of insulation increases a* plants become more Compacr, with hot linn and equipment closely spaced. 8y the same rotor, more easeful considera* (ton o! insulation requirements and applica tion will return greater dividends. MC 422262 B 0054 -6 : . ' 000920 w t FOR BRAINS Management and engineers. like lawyers, are glad to find precedents to guide current decisions, Sul the leader in his field is also alert to peculiar conditions that distinguish his case from any other, old or new. Each insula* (ton job is unique, Even two identically designed plants in different sections of the country would most likely have differences in labor and fuel costs, equipment efficiency, length of amortization, insulation cost, period of op* eraiion, environmental conditions, and the cost of money. Failure to consider such variables may be wasteful in two ways: <a) ihrrt may be more insulation than a necessary for some parts of the system, and <b) lass than b economically justified for others. The variable that myst be analyzed anew for each job, whether hot or eold, is the relationship between the cost of applied insulation and the cost of energy; and for complete analysts we must consider the cow of capital eqai'pmctK and the cou of he money to buy the capital equipment. This relationship b the basis of the economic thickness approach, which is defined as the thickness of a giverj insulation that *-<// save the greatest cost of energy while paying for itself within an assigned period of lime. The amortized cost of insulation obviously increases in proportion to thick* tseis. but the tots} cost of bear ks for a e/ed /Weiness decreases. There fore the thickness at which the sum of these two costs is a minimum fall expenditures considered) is the most economical. Ahhough this system requires close attention to the actual details of the job. a long scries of calculation is usually not necessary. The basic economic thickness equations arc available in standard reference works, along with chans, tables, and nomographs, from which close economic thicknesses can be read for a wide range of applications. (For a simplified method of calculating economic thickness, see pp, 13-15.) Where inexpensive fuel reduces the total com of producing heat at. say, the main steam fine leaving a boiler, less insulation will be needed for maximum economy than if (he plant were located far from coat, oil or gas resources. A petrochemical plant in Oklahoma will usually specify less insulation than one in New Jersey--unless, of course, the need for close process control calls for greater thickness than would he required on an economic thickness basis alone. Note also that not ad pans of (he same plant would be evaluated w,.,, t c>"i factors: e.g,, waste heat has a different value than prime heat. Occcauonslly you may find a sound specification which calls for comparatively little usukition on economic grounds, but which may be inadequate for personnel safety at certain points of the system, Obviously. additional insulation must be specified io bring the surface temperatures at these points down for safety and comfort. T nc 42217 P 0055 Here are some of the shortcomings of the surface Only it safety and comfort are involved is the temperature approach: temperature at the surface of the insulation a significant 1. Ambient air temperature* If one wall of a boiler matter. 8ul refiance on this one factor as the sole guide wfefi s surface temperature of }}5 F is exposed o air to thickness is a common violation of sound engineering at t05 P, n will lose much less heat than another wail of doctrine. As far hack as 1926 L, B, McMiJIan declared, die same boiler at 135 F exposed to air at 75 F, ifi discussing the use of surface temperature, "probably no other conception ki connexion with heat transfer is to generally misused," 2. Air velocity. Different me* of air movement over a surface can cause heat losses to vary over a range pf several hundred per cent. Air circulating at 400 feet It has long been a practice in the industry to pub per minute (about 4H ertph) will cause a greater heat lish sample recommended thicknesses of pipe and block lost from a surface at 100 F than still air will cause for insulation at different operating temperatures. But these a surface at 150 F. suggestions apply onfy cc an "average" set of conditions that practicel)y never match n actual case. NlMA H rec ommending to its members that all tables showing heat tosses and sitri*et temperatures be accompanied by a qualifying statement to this effect: Carrying this point further, we might find that the higher the heat loss due to air movement, which reduces surface temperature, the less insulation would be specified according to surface temperature requirements atone, With air movement, the surfaces become progressively Insulation surface temperature* are given cooler, but they lose an increasing amount of heal! only to indicate an appropriatevalue for pur poses of personnel safety of fire hazard for hot surfaces, or for determining whether eontfemat'oo occurs on coid surfaces. They are theoretical values usually based on one set of eendtttons such as in ambient still air at F, Ao*J surface temperatures vary widely depending on the nature of the insula tion surface finish, the temperature and veloc ity of air over the surface, radiation to and from nearby objects, etc. Surface temperalures alone are absolutely no reliable tndtea- 3. F*>xiiiry of hot or cold surfaces, Heat trans fer by radiation varies according to the differences in the fourth powers of the absolute temperatures of the radiat ing surface and of iu surroundings. A slight decrease in the temperature of an environmental surface produces a relatively great increase in radiation low, U a hot ves sel has one side racing a cold wall and another title facing a nearby warm surface, the side facing the cold wall wilt have a cooler surface, and according so surface temperalure tables would need Jess rnstdairon--and would Jose much more heat. I tion of heat foss and therefore should not 4, 'mirtiviiy\ The bright polished surface on some be specified or used as an exclusive means of types of jacket applied over insulation has n higher sur vclcctmg the proper thickness of insulation, face temperature than a dull one. but might he lo*ny Sine? the mayor purpose (or usingheat irtMtU- beat at only half the rate. Some metals, r.g,, aluminum, tion is to save valuable beat, {fie proper thick have nriah*ef}* tow radiation tost h tie*, but the lots ness to achieve this objective should be based increase* as the Surface becomes dull from oxidation. on economics.... Uepovrs of oil and dim also increase emissjviiy. rfC 422167 Q 00*56 I II rNCt fen* PffE astrutM swim ettanwa eina ASBESTOS iMoMea Mieote **4 GWefi CAt&tl* sucwe (Ctkien Stowe e AsMitol uemu Hcttftr 120C tHrinutniiien* vm C-J4S COUTiAR CLASS Forfeitedturn8SS) SVU fcvnet, AjSWfcWtf fe* SteXi et0M4TWOMcA*eCSfOtAUSSS0<UelCAudAttcittU m 0461 IGM (tnkti 22feflftW 1600 C434 1900 C434 upuMttuiUnrrrotaHriUwwOt*tdMfli HM47I1 firifte !i, Den e srtHsrfljUeUitim^ HU-5 SSI,Type W UU2TSi&etfel.Cto4& HK4423, Dm 2 Cade^,CUu4 D*aiB,Cuue.Typel KH4SS1 Mm 2781 &*de 11LDm e, T* If blocks asd mm mm. f88 Seek. SU| * Clew U Ten? fflrjiw GutUr? int h Meam Teetp (Fine Tap, Ojjawc Batted H^n Temp i^tsr^-Typt Mm* Aeieiteecetfi WiOWSUCAU {Celoum ObUrt AsbesEn) OitUlA* CLASS COiiftAS SJUCA (fomeS OjATOHfiCEOirS StUtt (QistonKtovf Sj&u Ad Asberto&) % MAGNESIA (SUiic MitMtiBtti G*ftcA*ie w* Asbetto} swat* ffcta *t, sag os 9*4 U*r Temp ffkjnw 8i(to>) 6CC 0420 2 C400 SW 0261 C-3CC Utt C2 1200 C444 HO MO 1GGQ tejtTici 22MWU Ii9ScMe C433 C4 CM C319 2 MTS MgJ.2^j &ria l am t MU42S44 MH4S15,CUiSKi45 WM-CCaJS, Dassn ] 6 2 KU4219,CMMSb6ie hbi>tui9,cmn KH4S81$.QfcU4 hiumoto* KlU&Ttti Dm l 22C4 Mg.|.?42 mmi 8UKKCTS in* rats U* T"p (Feig ftbtf, Qgit GitW) HigR Temp &nt|nc linffed CAtCRfM SlUCAtl fCUeivm SAmrte. Jutes* a Itetni OsATttttCE&S SlUGAiKomieeftj*Sfltu enfi fcbetiati KCNCStA<&OK MnfttfTi CMtott, Aibftto n4 feWwt WW8M TfSES (tod Si V 0*uJ inwtetmj Se4M Cle; M tad1 farjpj O^fflesflfMettaij Cemreil ottf fr&SfO MAOtU neat {he*, sut C= SMiti Miu^eB^oaetf UeeUL FieidM fritnic 8ooM) n cm, &m.cuui )KC &2.ctus2 1333 10 MST W C-ISJ m &1S 1203 C40 mi9-n6 Type8 Ma-C'29CS,Trt^S IKt C-2tt HH44SU 403 C-264 WL.I40 fet-t22CZJ" M62 utuiesBB HM-jm 1" A4 Nh f SW. Trw (1 HHl-Xl Type El lHiS32.TTb<i H.|462, Type S HK.VMlTeE f-5S2,Tywtl Dm 1 HWSil HH4iS< Type! HH-t-SW, Dm A KH-J-SSS. tfw* feoTy mssLmi KH'I'SW, CUM&C,& W-S2iCUn3 (SUtflS&TypeV 1iCC$CaTypi HK4>166 mti-Stt Ttpe i ^riS<i Type i swrtrUJ Gm AeSmMn (tl! &tm 9?Ml Offtw LOOSE 4 mim. fiM iea. hh * SRMliUTEB IJCB &&2 4ffi cm MQ ixe *m,WX5*27 Wl+lW?Sn KM IHL Type I KEU442, Type 8 WMS&Typett MI421, Type l~4ettt Type 0~Con <d t',, m h **** *#* wm< ***h a-wi m Reels'** ai ** Vnt<*nete m* sx*ico M $ t(N"t **' <o iMUlMW ** * 0K<'*k *4<T nr #* KMtN l M J IU tt**2 weJ| is n #*'( a: toK^-w**** *u t '*? s's is wk> -***i' i*f* Ms1 a*< <f* M<rW feat **e fiet euMien tr> Mit4s??i MWU^I ji, U r*u<i*s< u:>*r ** M**i *r*r ** *mu> ' ' sudiO ai*wt ff>hswWn *i41UU *w ^nifrUJ V SesiiMstaM usu IV^b m Jew? # kss> iwe vigi s< 'ti'ei'M* iscw. e /*C 422262 P 0052 000923 OF INSULATION Thermal insulatw* are suppled in various lama. They are molded or cm into cylinders, half cylinders or curved segments far application to piping, and into fiat or curved blocks for vessels and large equipment. Insulating cements come in dry form w be mixed with water, for application by trowel on irregular surfaces, or as a final finish on other types. Fibrous materials. in addition to the above forms, also come in flexible Waters. s*Pi>*igi6 /efts, and loose end granulated forms. Pipe insulations are made in "simplified thicknesses," in which the outside insulalion diameter is approximately the same as the diameter of standard iron pipe, so that building up the thickness of insulation in layers is possible. Actual thicknesses are related to but vary above and below nantinel thicknesses. All pipe insulations are fumHhed in I. Hi, 2,2!i Inch, etc., nominal thicknesses, asd is specifying and ordering, pipe Insulation is referred to by pipe size and nominal thickness only. ASBESTOS is molded from asbestos fiber, principally of the amosfte variety, combined with diatoms* ctous liHca and bonded with heat-resisting binders. It comes in pipe sections and Is used for temperatures up to 1200 F. Density ranges from 15 to 18 pounds per cubic foot <pcf>. Typical rooductiviiies~>expressed as "K" factors, or Btu perthourHsq. ft,) (Fahrenheit degree per ineh of thickness1---are 0.37 at 200 P. 0,47 at JQ0 F. 0.57 at 600 F mean temperatures. converted by ueam pressure autoclaving Into hydrous calcium silicate, it is furnished in pipe sections and in fiat and curved Mocks, to applyon heated surfaces up to approximately 1200 F. Density of calcium silicate insulations ranges from 11 to 13 pcf. Typical average conductivities arc 0,3? fitu at 200 f. 0.47 at 400 f\ 0.57 at 600 F mtan tcmperaio/e*. A second type of calcium silicate of slightly higher density is suitable for temperatures up to IWW F, Typical conductivities of this higher temperature type are 0.46 at 200 F. O.J# at 400 F. and 0.7|> at 600 F mean. DIATOMACEOUS SILICA or diatomaceous earth is made from the siliceous remains of microscopic dwomv with clay and asbestos for bonding and reinforcing, it is molded Into pipe sections and tegmenta, and info fiat and curved blocks for large surfaces. One type is suitable for tem peratures to approximately IOdd F, and a second type <o 1900 F. k re often u*eJ as the inner layer of two-layer insulation construction so as to permit use of a lower temperature product as the outer layer. The 1600 P type has a density of 21*22 pcf, with typical thermal condueJivitrcs of 0 66 at 500 F, 0.70 al 700 F, and 0.74 at 900 F mean. The 1900 F type weighs 23-25 pcf. wb typical average conductivities of 0.7! at 500 P, 0.75 at 700 F. and 0,60 at 900 F mean. Diatomaceous silica also is available in aggregate form lor fill and as an ingredient in cements. fiC 422167 & 005$  CM?` 00092J TYPES OF INSULATION GLASS (CELLULAR) is made from a modify boro-silicate type of glass, melted and formed by healing and chemical process. The resulting agid gfessy material conisin* sealed eellf and sghs approximately B to IQ pcf. ll is used for insulating piping sod equipment operating at temperatures up to 800 F. The material is furnished in pipe sections and in Hal and curved Mocks, Typtcai thermal conductivities are 0.41 at (00 f, CA8 at 200 P and <?.35 at 300 F mean. GLASS (FIBROUS) irwulutwns are manufactured from specific proportions of silica and other gtes?>fcrm<ng compounds. These are fused and drawn. flame-blasted or spun into boro-silicale glass fibersof consistent chemical composition. The fibers art combined with binders and molded into self-contained boards and cylindrical pipe insulation; with or without binders they are formed into flexible blankets and semi-rigid felts; they also come in loose forms, Fine-fiber type flexible and semi-rigid blankets, Uh organic bioden, an used up to 400 F. in densities of 0,65 lo 3 pcf. Conductivities of the 0.65 pcf material are 0.2$ at 40 F, 0,3j at H>y F. and 0.58 at 300 F mean temperatures; of the 3 pet material: 0,21 at 40 F. 0.23 at MX) f. and 0.35 at 300 F mean. Typical conductivities of 3 w 8 pcf semi rigid fell uouhf be 0.24 at 40 F. 0-27 at ICO F. and 0.44 si 300 F mean. Several lypes of highstrength, long-testik-iype glass fiber blankets are available In densities from nomi nal tUn pcf to 3 pcf and arc used op to 400 F with binders, or SOQd F without binders. Molded pipe insulation. fine-fiber organic bonded, it used up to 3?0 F, At 3 pcf densdv.conductivirks are 0.2tuiJOF.0.2} of 100F. ami P.29at 200Fmean temperatures. Blocks and hoards with organic binders are used up to 400 F. Typical conductivities fiv denstic* of b-10 pcf are 0.28 at 100 F, 0.35 at 200 F, 0.43 ac 300 F mean. S5% MAGNESIA *. a molded material composed principally of basic magnesium carbonate reinforced tibvr. U b used on bcuied surfaces at temperniurcs up to 600 F, and comes <*<*'* tecit&n anti tegmerm foe pipe*, and in flat ued curved hirxXi lot other \urtjcc. It ^i> comes in dry cement form to be mined with a(er and applied in a pfjstK vtjte * pipe tUtittp and other irngoUr urtat'ev Wher* temperatures exceed pt F it in often ywd ax the outer layer over a di-itomsxn wl*tj inner layer. Density ri! to 12 pcf. Typical conductivities arc0,35 at MX) F. U.3K at 200 p, o.42 at 300 F mean. rrc 422167 . 0059 MINERAL F/BERS ROCK AND SLAG FIBERS (For Glass Fibers,.. see Glass (Fibrous) page 17} Rock and slag fiber* are made by melting siliceous rocks and slags and steam* blowing or spinning the molten mass into fibers. These are combined with binders and formed into boards, blocks, and cylindrical pipe sections; blanket* or felts are sometimes encased to wire mesh. Fibers in loose or granulated form are wed for packing into spaces. Combined with high-temperature bonding clay or other binders to form cements. ibty are appiied by troweling to form a monoirthie insulation. Blocks and boards with inorganic binder, such as bonding clay, asbestos fiber, etc,, are used up tft 1800 F, in densities from 1$ to 24 pcf. Typical eonducitvhies are 0,39 at 200 F, 0.49 at 403 F, and 0,59 at 600 F mean. Other block*, made with organic binder at densities of 6 to 16 pcf. are used up to 400 F; typical conductivities are 0.28 at 40 F. 0.29 at 70 F. ami 0.30 at IU0 F mean. One type of blanket, with felted fibers held between wire mesh and with or without binders, is used on fiat and cylindrical surfaces at temperatures up to 1200 F, Density ranges from 6 to 15 pcf. Typical conductivities are 0.35 at 100 F. 0.49 at 400 F, 0,63 at 600 F mean, A second type, with organic binder, consists of lefts isemi*eigi4t up to 6 or 8 pcf. Typical conductivities are 0.26 at 75 F, 0.27 at 100 F. 0.35 at 200 F mean. One type of cement, applied in several heavy coats to build the required thickness, has a density of 24 to 30 pcf and is used at temperatures up to 1800 F. A second type, a hydraulicmelting, fousbsng cement, is quiet hardening, has a density of 30 to 35 pei. and a used up to 1200 F. is 000926 THICKNESS HOW TO FIGURE IT Given the principle, "Make the most out of your mvewnern," how do you emulate at wht pew* you are getting the most value out of your insulation? Every job must be !' culated on Its own tarms. but no special still In engineering or mathematics is required to use the formulas presented here. The following simplified example does not consider the cost of capital equipment or the cost of the money to buy the equipment. Calculating the economic thickness of insulation to be specified for any pUm requires easily obtainable data on ten basic factors. These ten factors arelisted m she leftcolumn below, while the figures of a realistic example arc presented, point for point, m the column at the right. The example for hot pipe insulation, but the same method can be used for flat sur faces, end with obvious modifications, for cold iosulaiioo. SIGNIFICANT FACTORS: 1. Vai of fuel (fuel cost, plus cost of labor, maintenance, water, etc.) 2. Hours of operation per year $. Btu content of fuel 4, Efficiency of combustion 5, Averageexposure lambicalst'itt-airrempemure) 6, Operating temperature of pipe (cause of heat loss) ?. Pipe diameter (source of heat loss) 8. Estimated f Installed miuJxtion (obtain from insulation manufacturer or contractor) EXAMPLE' t. Otfuf.OS/gaf. <$.C7/gai, fuefcosc, plus $.01 for maintenance, labor, etc.) 2. 6760hr./yr, 3. 14S.OO0 Blu/gal. 4. 8056 efficiency 5. 80 F ambient still-air 6. 600 F operating temperature 3' pipe size Estimated cost: lAsuiaii&ft TnUmru r \'A' VA- y i`A' CestMM Un, ft.el $200 $230 $260 $29$ $340 $395 V. Amortisation period 10 Heat loss per lift. ft. (or sq. ft if fiat, or heat gam in cold systems) 6 yt. amottixattoo period Heat lots in Biu/hr./jin. ft, at 600 F op erating temp, and 80 F ambient (obtain from insulation menufaeturar's tables) TeitutM or m* V 2W" y MK*/f*ttMimi#. n. 2437 230 175 ISO 133 no m tj PIC 422167 Q 0061 09`^ oo Using these data, economic thickness is determined by following the three step* below, A. B and C, The objective is to find the hsIOinch increment of insulation at which (he total cost of heat loss and insolation is least. This is shown on the graph presented as a summary of the calculations, (Note that according to a realistic economic calculation, 314* will cost less in the long run than 2*,) Compute cost of heat loss per yr, per 100 lirj. ft. by using this equation: fitu. hr.-'lm. ft, * hr. yr- * Vgal. % 100 ^ ^ 8tu- gal. x efficiency TiattxeeXtlMiefni ' ? arisMCeeeai;Ktnu.>*w rr. 0' 7437 * 8760* $.08 x 100 145,000* .80 $1472.28 r 230 * 8780 x $.08 *100 145,000 * ,80 * $ 138,95 ivy 175xR780 *$,08x100 143,000 x .80 s* $ 105.72 t- ISO* 8760X $.08 X too 145,000* .80 as $ 50.62 IVi' 133 *8780* $.08 X 100 145,000* .80 s* $ 80.35 y !?n* 8760 *$.08 x 100 145,000* ,80 m$ 72-50 y*` lit *8760*$,08*100 143,000 * ,80 *$ 67.06 V E fnitalied insulation cost per year equals cost of 100 linear feet of insulation divided by the amortization period (in this example 6 years). tniekiMsi1 1" Hr InitaiHS esu*r. $200 6 " S33.3S --5230 e= S38.S3 2* 3* 3't* il r-i j %( $260 6 ** $43-33 $295 6 " $49,17 $340 SS6.66 6 "" S6583 i 7f g 7} j gj ' 0tof<en. leusiM* Total cost per hundred linear feet pet year Step A + Step B *iat<* S*i*tM** 0* r l*a* v 3's sue * (xi*t iei ui 472.28 J.tK9` 1 (>5 72 90 62 80.35 * 4 67,06 ttt a Iimwi. (test) S 0. 33.33 38.33 43.33 4947 65-83 Taut Cd $1472.28 172,28 U4.05 133.95 129,52 12 * ! 112.89 In this example. 3* i> the economic thickness, because either a lesser or greater thick new retutu n a higher total yearly cost. Cat* 9 * W f par 100UAM' MC 422167 P 0062 FOR FLAT SURFACES nno 9:>8 The uMe feetow deals with insulation of fiat surfaces. ai 700 F and SO F ambient air. uirig insulation with an average '*K'* of ,41? et 2SK? F mean temperature, in the first >ar alone, the first inch of insulation xwx% 52,4 J persq. ft,. more than it* installed cost. The real problem, ho much more insulation to add. in half-inch increments, anti still save more than its cost. Is shown in (he toWc*. AuamcO ts an umoei'nnion perioJ o$ sen y&ir\ and a cost of 5.15 for cads jtUtikmal half inch, divided by ten for the tearly charge per sq, ft. Each increment saves fewer Btu than the fast, until finally the extra half inch to male 2'** costs more that? it saves, So 3' a the optimum thickness. Dollar value of hear saved by Insulation for flat surface at 300 f and 80 F ambient air tnivIVHn tfi*<*:** |li 1' 22V* 3 3vi' H*st H# 620 70 SO 36 31 36 23 feel Qfrf fauamtftlet tv p*< *e o ** tv 00 550 550 570 562 20 12 569 7 564 597 5 3 *ter *al u>M MBit** tWMMltl p*t im teras m 543 0413 0 4,617 0 4.617 0.436 Q.313 4.602 5497 o.ns 0-105 0472 0.226 5,156 $.202 0461 0444 0.202 5429 0.027 rial 0Uon p*f t f SO* |iM 0 2.41 2.499 2.551 2.582 2.604 2.617 Q 2.41 0.096 0453 0431 0.022 0.013 ECOVOM/C TH/CKNSSS FS. SURFACE TEMPERATURE This graph demonstrates the savings in valuable heat when economic thickness rather than surface temperature is used as the basis of selection. Economic thicknesses are given for 14" pipe at two heat costs, SO.40 and 50.80 per million Biu*s. under conditions of ambient stillair at 80 F and 8,760 hour* of operation per year. By comparison; at 30,40/miUion Biu. thicknesses chosen to meet a surface tempera* curt of 140 F would fall a full inch of moreshort ofeconomic amounts, at operating temperatures of 1000 F and below, and this inadequate insulation would waste heat for the life of the equip ment. At s heat cost of SOSO' million Btu. the result would be even greater waste of fuel dollars as a result of specifying insulation merely to meet a 140 F surface lemperaturd. At 600 F, it would e'en be economically sound to *dtf i` more imttleiion. Al 900 F. more tfea y addi tional Insulation is indicated than would be required for 140 F surface temperature. Even at so low a temperature as 200 F. it would save money to add almost 2* more. if cost of capital equipment and cost of money to buy the capital equipment had been taken into account, the conclusion would have been similar hut even more startling. An in vestment of dollars in engineered insulation should bring a return comparable to that from a more efficient generator or other specific equipment. MC 4222 67* P 006 3 M.V 000929 n i * I NATIONAL INSULATION .* NATIONAL INSULATION MANUFACTURERS ASS'N. MANUFACTURERS ASSOCIATION Vou cft <lepcrxi upon the quality o/ thermal insulations made by the members of the National Insulation Manufacturers Association. The composition of these materials based upon exact ing research, and production is subject continuously to careful control. They will give the performance desired, when applied by the aWe contractors with whom NIMa members work. NIMA members would welcome the opportunity to have their field engineers survey the insula tion in your plant or to advise on insulation of new facilities. JV . !* . MC 422167 P 0064