Document GmLd9yGyNm1GZzJz6Q0Xz9Z8v

ww* imm sc.mww M wupmuwiBm LIA10282 LEAD INDUSTRIES ASSOCIATION 4*0 LOOMerON AVSHIHI NEW TOtM IT, M. Y. MCTAULJC LSAD MtOOUCT* prvsaso* torch 18, 195) CKBflCH. gJLLTTJt VO. 51 STOv'FTTt T7W:XTmt CT cctisrj'CrzcH mrta j j l s 8PVMXTI How to evaluate th* economy cf construction a*t*rials la pmblew faced t tom* tine br practically *11 engineers and purchaslm; sginta In tbo chealcoi process l:.du3try. Her* 1* aystsw adroestnd In *Ch-ic*l or.gir.eerli^n (January, 195)) that should b# of interest, especially to users of lead equip ment. It 1* shorn that In many sppllcstlons lead pipe can b th* wict aconowleal watsrial to us* dec.'it* a higher noa livid corrosion into *r.d higher Initial cost, In the cac* cited, lead pip* pu-cved to bo actually f\r loot aponalos for oqalTalcnK. aerric# than Dtrlron, rvild stosi, wor.al or m cast iron* Hem t o n3; omaMint ntrii Dosl^n anyvnasrs oftan <b net reallt* the trororyteu* l-tport-anc# of corrosion dots In th'tr design work, for axanple, an enyl-veer way bo **ked to detan-In* tho rest oeonorleal piping aatorlal for haixlllrg 60 poreant HjSOjj at 2CO I. By consulting ths literature h* car, usually find corrosion data for rush a cast, such as listed In tha tails on pegs ). CiThand, na-iy design engineers facsd with such a tabulation would ba inclined to select th# cvaterlal with th* lowest corrosion rets, usually expressed In inches penetration per year (lpy) and would probably rat# tivss In lncr***lr.g order of corrosion rsts. In this case Durlron would b* first ar.d cast Iron last. But this doss not nscsssarlly fir* tha nest sooner.leal Installation, Isnr: lug that contamination of th* oroduct by th* construction aatsrlal la nut a problr* torn th# proper procedure Is to detemlne th* catsrial ahich dll give the lowest coat per year) not nscsssarlly tha law* ttl corrosion rsts. w, m*i ntxmw LIA10283 CKTNEU. KJLL'.TDi NO. SI -*- lUrch lfl, 195) To do this wo first eonputo tho Ilf* expectancy for Mch material la the table and froa tht (plus installation cost lnforrktlnn) dotone in* tha w* tual ccn per year for oaeh material, To otsrt off e cake tho following Meumptlonat 1* Since w* are dealing with piping tutorial wo will msraa* Uut IOj foot of pipe with U fittings and 2 valves will bo used. 2, Be will asrxco that tho useful oervlee lift of tho plpo ends idven half of tho original wtll thickness boa boon corroded any. K.1 TO CllCTUTD Ami IS-TOJO. CftSTs With the oboTe assumptions *o proceed by four stcpsi 1, froa tho plpo also and schedule foebor* dotorwlao tho wall thickno'a of each material to bo used* 2, Cowpute the life espectanoy In jrnri by dividing half tho wall thlcknooa in Inches by tho axpocted Ipgr. ), If possible, aocuro actual data on tho labor and rot-rial oost for each construction material under consideration.** k, rrori tho total coat and lift expectancy cslculato tho yearly cost of och piping string by dlriding the cost by the Ilf* expectancy. Following through that* four steps for each construction aatrrlal produces the table given hero. Tho oo't econodeal rat*rlal| that if, tho ono with the lowest cost per year, turns out to bo chnclcal lead which rotod oocind in corrosion rating, riot# that the ordtr of increasing coat la quit* different froa the ordor of Increasing comsion rato a Schedule nussbora aro given In A.S.A. Standard B36.10 and refer to plpo wall thickness, oo Jf ouch data aro not resdily arallablo uso that of K. 1. Dixon on plpo coat estimation pChwtieal friglr.eerlngy pp, Janunry, 1950), Dixon's report gives labor and materials cost for aoet kinds of piping materials but is based on .hily, 191*1 costa. To allow for protent day Inflationary values It lo nocoosary to factor* hla data up to the pTss~nt b tho us* of a suitable lndox such a* the Marshall anl Stevens Inlexte published monthly and revised quarterly In *>clcal Irglnooring,* The data used hors woro ta*m free Dixon's flguroa. CUQIXCAL !WJL.TDi NO. 51 3 lUrch 18, 1953 Ecorwclc Cjay-rlstr. of plptr^ ter HA.-^llr.e 601 , ?OC f tutorial Xnchea Tfe*arr. Vail Thietcneaa, 7-In. PI pa, Inc hoe Ufa fccpeotancjr. Tear* Total Coat pear Cort, I*r, $ Cbaeleal band 0.008 .187S 11.7 613 53 Durlron 0.no6 0.151* <9ch. 10) 17.8 991 78 VU4 Steal Mnnel l rtal o.no O.CU5 0.218 (Sch. 80) o.i53* (Sch. to) Oji 777 1.7 1,181* 693 697 Cast Zroo 0.890 0.718 (Sch. 60) 0.1 176 1,760 Pata frea Toch. Boll. T-3, Oct. 191*8, p. 37, International It ek**l Co. Thl* rethsd ta t<a tilled to ar,e eerrrsire enrlroneant and to oat other t/pas of corrosion resistant equip-art, thu< enabling tha design engineer to eelect tne nost economical material for ar.y particular aervlco.