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FrictionB: acceleration of gravity, ft/sec2 (taken as32'l74ft/sec2 in makingconversions).hr : head loss due to friction, ft of liquide : absolute roughness in feet-see page 3-5h, : Veiocity head-ft of liquid zk : kinematic viscosity, centistokes : -rr : kinematic viscositY,-ft2lsecf, : i""gtll of pipe lnti'ai"g equivalent length for loss throughfittings - ftm: hydraulic radius := perimeterflow area(use in calculating flow in open channels or unfilled pipes)p: density at temp-and press'.at which liquid is flowing' lb/ft3gpm: flow of liquid, gallons per minute'" *: absolute or dynamic viseosity, lb-sec/ft'?V : velocity of flow, ft/secs : densiti, g/cm'r (water at 4'C or 39'2'F : 1'000)z : absolute or tlynamic viscosity-centipoisesHAZEN AND WILLIAMSAlthough the Darcy-Weisbach/Colebrook method (on which thetables in this book are based) offers a rational mathematical solu-tion to friction loss calculations (since it can be applied to anyfiqria except plastics and those carrying suspended^solids) someengineers prefer to use one of the many empirical formulas thattli" t"", developed for water flowing under turbulent conditions'Of these, ti,e . wiJ"fv ut"a aid accepted is the Hclzen andWiliiamsempiricalformulasinceitisconv enienttouseandexperi-ence has shown tf,,i-ii pt'auces reliable results' In a convenientform it reads: too ,r -s gpm,,.hr= t1 T ), d-""*This formula is basis a fluid having a kinematic viscosity' u 012 16 ft'lsec if .fSO centistokes) or 31'5 SSU which is the caseio, *ut", at 60"F. But since the viscosity of-water can vary from 32'F to 212'F the friction can decrease or lncrease asmuch as 40Tobetween the two temperature extremes' However' thisformulacanberr."dforanyliquidhavinga viscosityintherangeof centistokes'ValuesofCforrutio"typesofpip ewithsuggesteddesignvaluesare given in the foUou'ing iaUte wlttr corresponding multipliers thatcan be applied, t"ll"n 'ppiopriate' to obtain approximate tu'uttt' ,-,I ) mg"ttoll-Dresser Pumps Cameron Hydraulic DataHazen and Williams-Friction Factor C**Type ol pipeValues of CRange-High = best,smooth,well laid-Low = pooror corrodedAveragevaluelotcl ean,p ipeCommonlyu sedvalue fordesignpurposesCement-Asbestos ..... .......Frbre ..Bitumastic-enamel-lined iron or steelcentfltugally applied . .Cement-lined iron or steel centrifugallyapplied . .160-140160-130150r50148150r40140140140C opper,tubingbrass, lead, tin or glass plpe andt50-120r40130Wood-stave145110120r10We lded and seamless .....lnterior rivet d steel (no projectingrivets)....Wrought-iron, Cast-iron ..........Tar-coatod c6t-iron .I 50-801 50-801 45-50130139130130100100100100Girth-rivel ed steel (projecting rivets in girlhseams only) ste l (projecting rivets in girthand horizonlal seams) .. ... ...Vitrified, Spiral-riveted steel (llow wlth lap)., sz-es130120115110100r00100100Spiral-rive ted steel (flow against lap)10090Corrugated steel6060Values of C150114011301120111010019018017060'Multi plier (Basis C ='100) ' Multiplier to corect friction loss tables (in previous editions-14th Edition and earlier); cannot be used with tables inthis book which are based on the Darcy-Weisbach-Colebrook Nole: the Hazen Williams friction factor "C" must not be confused with the Darcy-Weisbach-Colebrook frictionfactor "f"; these two friction factors are not in any way related to each loss-sample calc'ldTo illustrate the application of the Icalculating the total system head for Iexample is offered:Problem-referring to the accompqtakes water (68'F) from a sumP and d4" diameter schedule 40 steel prpe- Itfeet long and includes a foot valve adcharge line includes two standard 90 dcheck valve and an oPen the suction lift (h,) and the discLof flow is 200 (a) SUCTION LIFT-Data from tal'tVelocityPipe friction loss h1 : ft Per llThe resistance coeffrcient for th:K: and for the long-radius elborThe head loss due to PiPe foiction rThe head loss in the foot valve au\f2hr: K *: + suction lift (h,; : (? -'(b) DISCHARGE HEAD-The hed4" discharge line will be:rx\ , rm\Phead : -4511": $ Y -'lm3-8

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