Document mB8QQbaJKVkM20bdQKeN33w9Q

f 1: M Mli* 1 *--.- -%1|| tTi Ti^^MVxp-TT',r--------- M-fTTi^ \ .Lend IiicliiMtrle Ajutoclation 420 LIXINOTON AVCNUC NKW YOHK, X.Y. April 21, 1931, mw r m .* ' ^ wwy ju ^ yrpni un NiM fiWWpWF>F |gfJ* TO UZUBBHS UAjnJFACTOTDNJ LEAD PIPS: j 1 ? f( Owing to the failure of sons lead service pip* installations in the City of Taehington, D. C., a movement he* started in that city, to displace lead locally from this cld and useful application of lead, in favor of other metals. For several nonths the Lead Industries Association has taken an active part In trying to defend the Interests of lead pips in Taehington. Investigation so far has disclosed! 1. That the Taehington failure occurred mainly in the larger sizes of lead pipe, froa It* upward. hut that failures had also occurred In the smaller sizes (apparently froa fatigue stresses), 2. That Taahingtoa had raised its city vater pressure in recent years froa shout 40 lh. to as high as 100 lh. in some parts of the City* 3. That the weights of lead pipe required hy the Taehington building code end generally used vere *AA* or extra strong. 4. That failures in the larger sizes of pipe vere chiefly caused hy internal stresses bulging the pipe to the bursting point. 5. That Taehington piushers complain of the vater hanaer frequently found in Taehington pluablng. A further investigation discloses the fact that lead pipe sizes have little relation in respect to strength to the classificatlon 'strong*, 'extra strong*, or 'extra extra strong* (corresponding to A., AA or AAA pipe) commonly applied to then. In other words, the pluaber cannot proceed on the assumption that an extra strong 2 in. lead pipe will stand the same pressure as a 1 in, extra strong pipe. In fact aost of the trouble in Taehington la ascribed to an Ineorreot selection of lead plpa for the service conditions to he met, plumber* using too light a lead pipe far the it in, sizes and upwards. In this oonneotloa it is Interesting tr i i '1 'ASI ' l.mHi 'A'W Ajl.'WP* o^iirn that trad* literature epeclfying lead pipe elzee gives very little Information'for the guidance Of plumbere, obowing the bursting strength, or eefe preeaire, which nay he carried by lead service pipe. Lead pipe sizes and grades do not appear ever to have been atsi*J*aized. _ > With a view to improving the situation, so that' strong* or *A* lead pipe of all diameters will have equally safe working pressures, orzeulatlona have been made of the bursting strength of nyr>.voa sites of lead pipe, and, us-j Ing a factor of safetyy? 4 to"6, the safe working pressure ban been determined kcreover, run-cf-factory samples of , lead plpo have as'.^lly been tested to the bursting point In the laborst?'.-of the national Lead Company In order to oheck the ea)'>>atlons made. As a result of all this work thsre Is appended heriw5''Ji a carefully worked-out table showing representative ruu't of lead pipe iad the preeaurea that may be safely used with them for the weights Indicated. It will be noted that la each Size aa 'extra strong* pipe will stand the same pressure, and so on for the other grades. We have indicated In the table those pipe sizes which differ from standard weights cow used. It will he noted that the changes arw principally In the larger sizes of pips. yrca all the above, and in view of the highly com petitive situation In eervleo pipe. It would seem desirable ^ for the lead pipe manufacturers represented In the Lead' .. Industries Association, * large proportion of the total, te consider eeriouely the wisdom of making a few changes In ths specifications commercially used today so that when plumbers* and others select lead pipe they will be assured, for example, that all 'extra strong* pipe, regardless of its disaster, has equal resistance to bursting pressure. Will you, therefore, kindly give this subject your careful eone1 deration, giving the Lead Industries Association the benefit of your Tiewe, so that If a sufficiently largo enough cumber of manufacturing members agree, steps may bo taken to establish new standards for sons sizes of lead pipe. Esepootfully submitted, 1/.' a. - Secretary, 1 r family.'e i*t ! J CALCULATED SPECIFICATIONS OP HPPRB8BB1ATITB 8I2B3 OP LEAD PIPS 0 or A xs or U XX8 or AAA 8 or A X3 or AA US or AAA 8 or A XS or AA XXS or AAA 8 or A ZB or AA XXS or AAA 8 or A ZB or AA XXS or AAA 8 or A X8 or AA XXB or AAA rasrjB DIA1ETBB IB 8/8 5/4 1 U 4\ li 2 THICKNESS IN. .198 *.218 .268 ,196 *23 .295 .21 .4 .296 .21 .245 .313 ( .296) .24 .202 1 .27) .376 (.31) .260 (.24) .374 ( .255) .601 (.356) WEIGHT psa f t . LBS . SATE PRES SUPS LB. PEE 8Q. IB. 2-8 ol 2-12 3-8 60 78 100 3 3-8 4-12 60 76 100 4 4-12 *6 60 78 100 *4-12 6-12 7-10 (6-12) 60 76 100 6-8 7-12 (7-8) 11-4 (8-8) 60 78 100 6-12(8) 60 13-12(9) 78 19-8 (11-12) 100 *0 chang* rroa present specification. Bote- Number* In parentheses refer to specifications now la uae for size a Indicated; where no parenthesis are giren no change is necessary froo size now In uae. There there is onlj a slight difference between the calculated and present specifications, or whefe present specifications give an aaple factor or safety, no change has been SMde in the speciflostions. 14j vr \ N 3431.01