Document v1dBg2kDao74ErEXXaD6vZg2R

WMBIB i U.MPJCMP LIA1616A i m iiii ii Sit TA*iifsrfn UMieUUwkci -f- tfr,--,l ~fi-1- - Ic o ps c? Lr"Tcft: g t '-t ?' m b '. L.z:r'rr'--' c* v j .y .XfcA*?, AT itATAi, CT, .<v!'wr aAtTBATOPY, . 1.SHI5*0TOB, $ jdditlnwil copies with file- to* * - Vr . , .... PTLcmeg cr i,iid 8 cEmcraisrics ci it s ippucmao Uti li a fuo looting Mttl and an* that definitely promts a chtllmge te the engineer and designer. It probably hai nor* varied fields of applieatieB than any ether natal, tod these applications depend upas a broader variety of properties or chereeterUtioa than is usually the ease aaosg aetals, for instance steel le usually used because of its strength, copper for Its electrical -prepare tios, almln'-m asl nagne* lun for their lightness, but no one property of lead eon be singled out as being responsible for the preprndcrenee of Its usage* In fast roughly eno-third ef all the lead used la In the fora of ehsal eel confound* These include suoh various eospounds and applications as white load and rod lend In point, litharge and rod load la storage fe.ttorloe, llthorgo la oil refining, eorajslee cad varnlsho*. load arocnato la lnaoetlcldeo. tho lend ehrwi oxos la color plgaonte, tetraothyl load la high eefeoae posollnoj land aside la exploeivoe, lood 11 lento la glosoe, cad loed ocototo far may things, to r"*rliln ealy erne of the aero laportant lead oeopotasda* Still larger tonnages of lead are employed la Metallic form either alcae cr as alle^. In aoet of these applloetlcns the phyeleal propertiec determine whether the etal is used, and If ee, just how it la wepleyod. They govera it* s selection and dictate design. Aaoag the outstanding ehoraeterletlee ef lead are weight, denelty, seftness, anlleablllty, flexibility, low welting point, lew ultlaote tensile and ereep strength, 1m olostle llalt,-an ability to alloy with certain ether aotnls la si* aoet any proportion and an Inability to alley with othors, eolf.lubrication, lew electrical and heet conductivity, relatively high ooefflelent of therwal expansion, and abevw all, high corrosion resistance under a wide variety of conditions, lead is usually selected for use beeause it has one of wore of these ofaaraetwrlstlees The design of the produet or Installation, however, must also take Into eomlderatloa the other properties la wany Instances, Before discussing these eharaeterlstles In detail, a brief general descrip tion ef the lead Industry, where lead canoe frea and what It le used far, my be both Interesting and helpful. Historically lead is one of the eldest kaoee artels. It le Mentioned la Exodus and elsanrhere in the Old Testaaent. It was used to glass pottery, te wake solder and ornaaestol objects In tho days ef the Pharaohs. Old lead pipes Imre also been found In Egypt, In anelent India red lead was used as a ecsaetle aad the netal was usod for weights, purifying silver, and as a aonctnry aedita. The fleer ef the hanging gardens of Babylon was lined with sheet lord, and it was alee weed by the Babylon lano for calking belts late anconry, B> 8000 B, C the Chinese ends their first aosey of Iced, aad when silver coins eoae Into use later, tho gevornaont forbade working the lead --*-*-* te step counterfeiting. It SMld certainly orlpple sedern Industry If the lead alaec etepi ) pod In ordor te koop a fu. load slugs out of slot k .chinos. BronM eoimge mt aselcst Orooec and Soao eontoinod trm B te BC ef lend. ,ism w|ui p i iw e w sp n e w ie w sp p w p c^ c u p im/mmwmm* lUtofIP UI1L BHW BPJWWii LIA16165 .. i 4 iiiw ta lm 11 n im < m w iiiifiiiiiliir iiiil> liilir t* Th* Beoaaa had a w*ll MtttiUiM load pip* Manufacturing Industry, w*Y~lag It la IB standard sites tsd standard 10-ft. length*. Boats bath* wars site eftsa lined with sheet lead* Laid tat* tiny* besc u iapartaat artlolo of warfare. Modera ballot eore* tad shot w*re preceded by leaden projectile* hurled froa ships* cad aoltee load aad r* olid chunks of load descended upon Invader* flroa th* bottlatoato of boo logid eltloi. Even Icswm gladiator* ueod load knuckles to {in thoir punch** aero a* thorlty* Zb o llttlo lighter role, if you ooa say that of load, |m 1* told to boo* ora o load plat* oc hi* ohort to prooeroo hi* vole* whoa singing, X Iwngln* fe* rw duoo vibration. gad going to th* other oxtroao, Fhlletu** a toaohor of Ptoloay Fhllodolphas, was * this that he woro load oolod shoo* to hoop froa bolag blows ever. And* la poising, Oroek gaablor* used locd-1audod dl*o* Thoro 1* nothing saw under th* nau Th* United States is th* world's greatest produces of load* Is addltloa to th* biggest also production la th* world, ww also are produolag about a third of our seeds fro* ssrap* Th* biggest single leal eonsad-ag in-ustry 1* th* storage battery Industry and ac ether country approaches us in the use of autcstobllM aad consequently storego batteries* so that is a big additional lead ala* wherein BOjt of the lead uaed la the first plao* 1* crreatually recerrorod as **rap aad rec*fia*d* Briefly th* other *<xmtries which are big lead producer* are Bnl*** Canada* S Australia, Peru, the Argontln*, and eartnln European countrios such aa Silesia aad Yugoslavia* In this *ountry i&ssourl* sot ordinarily thooght of os a wlwtng state* Is th* biggest produoor, followed by Idaho cad Utah* Bo m guide to tho usofulao** and proportle* of load nay bo gleaned trm. a broad analysis of tho eaount used for various purposes* Thoso figures giro you roughly a eonperl* on botwoon a wartlso and Inst year* r. poa*otlao joor. Tow will soo that la general tho poaectlso uses of load or: also tho w-j--tlno uses* with soao variation due to tho extraordinary dnarnd for load for oueh Sf hr tlcolly wartins applications as casualtioa aad high oetnao gasoline* e mmmm wmmmmmmmmmm 'iiti'i MiftTirriiriTniwtii'iiiiiiigmiii''~i r "Mitif-'riB"*........................ LIA16166 p 'iTifctf'frlftL.-.jJatifa- . ... l^ *i . <*hildaaiaa^oy*M-u. fei - S tatlaatad laad Cemauaptieoe Storage Battarlaa Oahla Paint aad Humlah diaawltlce ^ Oil Sof. aad Oaaollaa Censtraetled Inaaatlaldaa Printing Poll 0, 1* OonRMtt CaraalM C4ort Railroad Autoaabil* Cana Steal-*ir# Collapalbla Tuba* tubbor 1 Hoa* Coating* 8 Braaa Manufaeturlng Laad Bead Balls Baal* ibraalraa Peadar XI**. fhaaleala thMlaaalflad * 1M4 *r ` " *97,096 126,946 98,600 60,666 . 64,670 103,240 *4,166 *2,676 16,070 6,730 7,870 12-660 26-786 7.740 10,310 4 678 16,266 4,136 6,600 8,465 600 1,670 690 1,440 4,098 124,960 T3IAL 1,073,606 * tom* - U*t Xnduatrla* aiooltUoi 194r4( 262,060 93,276 76,3*0 80,126 60,270 110,046 *6,096 83,946 6,640 1*0 4,694 16,640 22,828 16-716 10,460 6-4*6 13,136 4,000 6,616 4,24$ 1,616 no 600 906 *,010 114,710 * 906,710 tm l*t* axaaln* th* propertlo, of load and ho* thay ir applied induatri- ally and th* precaution* that auat ba tokaa to on load aoat adrmatagaeualy without getting Into pitfalla. Cerroaiea raalatnnae la probably th* eutataading aJtroetarlati# af load. o I holler* that should ho dlaouaaod flrat and at aanaldcretle length, IT you11 pardco no. Corroalon raalatnnae la cither th* anln or a attributing fhator la th* aalaatlao of lead for auoh laportant thing* aa aafcl* chotthlng, pipe, roofing and flashing, aaatlnga <n ataal and other metal*, and, of oouraa, ahaalaal aqulpaont* Load la raalatant to eorroaico by a wlda rarlaty of industrial ohaaiaal* af whloh th* aoat laportant la aulphurla acid. Sulpburl* aald la amployad la alaoat arary proaaaa laduatry* Ccmaaquaatly laad aquipaeat la at laaat a poaalblllty la dfci -< w/Simtotattemai pin u l iil LI A16167 nadU i .n -> inlr - *lmo*t *T*ry pro**** lnduatry, In general lit! rultti *ulphurlo Mid qdt* wall la eonecntratlon* up t 9e$ sold tad boiling, jta r*l*tan** r*ult* firm th* far*tltm on It* curfco* of a highly lnaolubl* coating of l*ad *ulphat*. Therefor* anything which tend* to r5r that proteotiv* coating tend* to laeroai* th* rato of o errcolon. Thu* aold pan lag through load plpo* at high volocltl** or a*Id la load reaction r***el* that 1* greatly agitated, l&sroaeoc eorroeloo and shortens th* Ilf* of th* equlpaent, Likwrl** tolldt la suspension In th* atld nay ahrad* th* ecuting and shorten the llfo of th* load, Load equljncnt ahould therefore b# Aeslgnod to alnlalio roloeitio* end agitation. Thl* 1* often &**q*pllh*d ky using larger pipos, for coaaplo, to giro equal roltno at roducod flow rate*. Tho*o prlnolpal* any bo said to apply throughout load** u*o a* a ocrre*lca ro*l*tent notorial and not Ju*t to It* a*o with culphurl* aeld. Load 1* u*od * orelolly to handle. In addition to tulphurlo cold, nany othor corrosive* lnalud- lng phoaphorlo aeld, ehrooLic aold, hydrofluorlo aold, eluninun, ooppor, forrla, ferrou* and nlokcl culphnto and sodlun thlorldo. I faaro h*r* a papor vhlah dw- -.iv ---~ _ 4. -.--. mu . U---, -- 1 .------ A- ^ ,, take tint now to giro you the datalla. Thoto who ara interacted way hare eoploo of this paper. Suffice it to *ay that In general It 1* the formation of an lnsalabio load *alt, suoh a* the sulphat*, phoephato, ohronate, and ao on, on the rurfaeo of the lead whleh proteote It against corrosion, On the otnai* hand If a relatiraly aeluhla land aalt 1* famed. It doo* not proteot the lend and corrosion nay pro ceed rapidly, iL good wxanplo 1* the rapid oorroelca of load by nltrle acid, lend nltaate being soluble. 8 In designing lead ehtalecl oqulpnont It* othor proportloc, partlwularly lb* low eroop ctorongth, au*t bo comidorod. Conccqucctly load Is rarely uced aleno, but 1c noro often a lining for ctool, wood, eonaroto or oono othor rtruetural no torial. Thcro aro cororal nothod* of in*tolling load depending upon r~*"*1-- tlans, In ahallar tank* and at nernal tauperaturo* loooo lining* aro usually sat isfactory. In tho*c the load 1* unually turned oror tho rln of tho tank at the top end giren no ether support, I m deep tanka or at higher toeparaturo*, a aarla* of rertloal cupportw are advisable, The** uru*lly on*l*t of iUl (trap* on 18 to 36 in, center* bolted through the load to tha upj ertiag ahell of tho tank, T.io* *t**l atrap* are In turn eorerod with atrip* of lead welded to the lead lining on *eah aide, for orbraaaly high teaparaturc* or wide tnparctur* fluctuation*, add brick lining* in* Id* tho load ilnlagt aro often used. Thoco corrc tho dual purpoea of helping to (upport tho load and lntulatlsg tho load agr.lnat the high toaporaturec. They alco protoot cgalnct noohonleul dnango to tho load. Another nothod u*od for extrano conditions la to uco load haeogaaoouily bondod to (tool so that It la cupportod ot all point*. Thl* olio lnproro* boat taanefar If that 1* o factor. In tho dotlgn of piping for prooo** inductrlo* tho tonporaturo and praceuro ha* to bo taken into account In calculating proper wall thloknoct, Tho usual foraula 1* prcaiuro oqual* two tlno* tho allewafclo fibre *tro* nultipliod by tho wall thickness divided by tho In*ido dlanotcr, Tho nllovmblo flbro *tro* doorocso* o* tonporaturo lnoroa*o, for ohonlocl load it 1* tnkan a* MO lb. par *q. In. ot roan taspsraturo and drop* to 80 lb. par *q. In, at about 300 f. mtrmmm LIA16166 -iwfliir-iT.ii. aiiilhnrrf- r,~--' * *' ---i- fr*tir i "n'-r n r 'rihirtineif"-**- Borlseotal load pipe* ors preferably supported aontlnuousl jr) vortical pip** wvsry fit foet. In pressures obev* 50 lb* *t*u pressure lead lined ln> or lead torerod topp*p should be used, Khan particularly corrosive solutions ara being handled In land pip* It In always advitsbls to allow * llttls extra wall thickness to eoapsasato far ecrroeion. Ths mm is tru* of sheet X**d lining* la ocrroslon r*l*t*nt squljaoat* X*d weighing l**i than 6 lb. p*r sq, ft. rarely being used for that pin-pose* and often th* l*ad It aueh heavier* Lead pip* it naually designated by It* actual la*Id* disaster and tlthar It* wall thleksees or weight por foot* Sheet laad It usually designated by it* thicks*** la frattiest of oa la*h or lta weight pr eqmre foot* Bh**t load weighs X lb. par tq. ft* for eaeh X/d* Is* of thickness op to oboot 90-Xb* load* which It l/i in* thlsk* Th# ms In point# to *entld*r la tho u*# of lead for *haal*oX cqiilpsnnt ar*( first* It It adequate firm a corrosion rodstcat angleT Moro often then not* It it* * S.~I ib. .lii MM iv X* WUluur*a louvpvottwur* *Wv Uh t # it * B* oa** hlttorlot of tlnllsr Installations at a guldo* tests on saaplot #ndor operating condition# cro advisable if potilblt* Soeoad* oro operating conditions llko ngl* tstlan* high velocity or lapurltlos la tho solution# tuoh as to ooeoXorato tho nartnl oarrotlon that night bo oxpootod1 Third* high tenporatureo c-tarlnlly lower th* strength of load* requiring olthor special support or jrotootloa or tho ato of took) othor actorlsl often at a taeriflso In earTOOlan roslstanoo* fourth* load in oatlly damaged neshaaloally* requiring protootlv* llnort if tho lood It llablo to bo struck by bard artlolo* or obrodod by oolldt *utpondod in solutions* Often load It suleeted for utt for various purpottt because It 1# highly resistant to serrotloa In the air. This is partloulariy true of Industrial atnoo* ph*r*t where appreciable aaounts of aulphur eonpowndt are generally found* Jt la alio r**Utant to *alt otaaospheres, tfndor tuoh conditions th* Ilf* of land la virtually intsralnetle, Witness ltad roofs anny hundreds of yoaro eld and tin no* of land a* flashings in ship eocstraotloa* Lead is llkOTls* resistant to torrosloo by practically all kinds of ontsrs whlsh.lsads to Its extensive us* for water pipes* Including pipe* t# *eodu*t salt g ward af ecutlgn Is advisable hart* Land pipe should not b* thieved to ooduet drinking water that is Tory *oft* not because It will b* attcakod to tte axteet of ahortenlag its life* but boesuso very aoft wator will dlstdre noro load than it generally oonsldorod safo for hum soesiaptlcn* However* tuoh waters will also dissolve topper or brats enough to oauto grooa vatcr and Iron enough to eauto rod water and rust slogging. Tho tn*vor V* to troat tho wator to giro It sufflslcnt hardaoas so ttaat It any bo sonduotod cofoly la load pipes* which Is oatlly dona, koslstanoo to corrosion by nost soils is oaothor shoreotorl*tie of load that rosulto In wide utago for hoc.thing oa underground olootrlool and eonmsoitow tlocs table at well at pipes* la gaoorol toll* uro oarroslvo to load la tho fel> lOTlag ardor nook* tlndora* sand and olay* suck being Moot oorroslro* SPWWIBSSW* 9 m up mm LI A16169 10 One general warning should be g lvac la ocmeetian with lead's aorroelen ritllteuM) It la rapidly attacked by free line la naw owerot, concrete or nortar in the presence of aelature and oxyger.. TXli cation disappear* whan the aweant beatwei carbonated fro the air la tlii*. Therefore whan using lead la onatruoticn, it ahould not be plaaod la contact with new aenant unlaaa it la eoated with aaphaltvra whlah prcteot* It until the aenant la aarbonatad. A coed axanpl* of this la tha uaa of laad ai oaf* pan* under shower atall floorae It la ataadard pruotiao be apotlfy that auah laad pane be coated with asphaltosa. Another outstanding aharaetorlatia of land 1* lta weight -- the henrleet of the eosnen awtnla. Laud weigh* abo-t 0.41 lba. per *u, la. er about TOT lb. per eu. ft. and haa a spool? le gravity of 11.37 thcreforo It suit uaually bo ax eludel fren oonalderatlan whare lightnei* la required ualeaa a ona other abarae- torlatla of lead oakaa lta aalaetlen eltnar imperative or desirable, la other werda lead 'a weight la often a disadvantage. particularly ce mobile equipment. for laataaoo laad la not uaually dealrod la alroraft. ^>u wouldn't think of oatnr laad la a plane If .In-fw. r narnaalts* w* atrialaaa etoal w-ha * job. lead atoraja batteriea are uaed la plan** beeaueo no other battery haa tha dealrod ohametorlatlee end you juet hero to put op with load's weight to jot than* Cb the other hand there are lnetansee whore sans other shareetarlatlaa of lead make It possible actually to roduaa tha weight of oqulpM&t la whlah It la uaod deaplta lead** high epealflo gravity, Several axuplea oould bo cited, 8 load coat Inga on oartaln alroraft squljnant hare aonstlmt reduoad total weight elnee they need not be aa think aa coating* of tome lighter natariala to got equal protection booauaa of load's hi*h ocrroalon raalatanoe. Lend X-ray ra linings are lighter than ecacrotc protective walla of equal Insulating value bo* aauae of lead's groat ability to stop hamful reye. Lead soil pipe la lighter than east iron soil pipe boec-'ec it san be used with thlrxor wnlle. Load roof ing la lighter than alato or tile roofing because It la thinner. Lead oountor-- btvlaoeoe nay roduoo weight booauao the weight onn be eancanttatod at the point *aro it has the aoet effost. Although load often nwst bu excluded fren consideration wboro light weight la important, there are many ipplio-tlone, auah na weights and counterbnlnneo*. whore load Bust got oonslderctlca aololy or lnrgoly boonuso of lta weight. In ouch usage, tha higher eoat of lead la balanced against It* ability to sere spaas at coopered with natariala of lower epeelfle gravity. Another con sider*tier U the low Mltlag point and eaiy orating of load Making it possible to fit lasd weights Into Irregular and out-cf-tha-way spaces. In (alsoting lead for auah work, lta softnsaa and low strength must e oustinsa be eonsldered If the weight la subjected to neehnnleal abuao. In such Instances, tha lead weight Is often enclosed In a oast iron or etsel shell. The high density of load. 11.37 pa. par e.e.. results la Its eeleetlcn JC for s airaber of purposes, Botmblc onong those Is X-ray protsstlen. for tha both t' and game ray stopping power of a subatunos la proportional to density. Thus for f L r; MOW r *111* lIXBWniri l' rl.m Hi.lir.- ..im .& : LIA16170 w-...U^iiw.uCji|:vt , V nMl-i' X-rsy machines of ordinary pc*rr, or whers spso* la tha controlling factor, laa4 la usually smplojwd as tha protact Ira asdlisa* Howsrar, with high povsrsd me- ehioai, tha thlotoesse* or lead required are expensive, ao that If apase end weight are not too important, eo.icrats, often In oct&laatlcn with lead, la po* orally employed. At a Batter of fast, loading X-ray axpart* now reccednnd using lead la combination with conerote whsnever aocorete is anplcyed because load re duceI eeattered radiation- The lew strength of loed again, must he taken Into eoosldaratioa la 4a- slgnlng load X-ray proteetlcn boexuts tho loud la not self-supporting and any supports fnstonod through tho load must ho so oorarod ca to prevent the oeeapo 1 of rays through tho fastenings. In tho ease of soiling* of X-ray roans. It Is usually on* lor to lay tho shoot load on tho floor store axtending out suffi ciently hoyund tho walls so that tharo is no dlroet path for tho X-rays he fal low boteoan tho top of tho walls end tho floor them. ir !;; riisly handlal In 1--1 for Us e--* reasons that It Is ussd for X-ray proteotian and stools fission Is naturally opening up an sntlraly new field about whioh not much aan ha said at tha w~aat. The thloknsss of lead to usa In X-ray protestlen has bees well worked out through experience and test aad depend* not only upon the power of the as- tins but also upon tho distance froa tha target and tins of exposure. These faotors have all boon emsldered In charts worked out by George Singer md George 8 Lowronoe of the C. S. Bureau of Standard*, nothington and tho Rational Research Cornell of Can.*.da rospoetlvoly. Their findings ham boon ecrrolntod, with the sasxcrclal thloknossos of lead, on a short whioh wo ham proparod and which Z will ho glad to send to osyano roquosting It. Load Is oao of tho softest actalo, its hardnoes on koh's soalo holng l.S, which Is about tho soao as tin and less than any of tho othor season metals. Tho Brlnoll nuuber, using c 1 eentinstar ball for JO ooeonds at 100 kllogrcn load. Is 3.2 to 4.S for eacaan load and 4.5 to 6.0 for chemical load. Softness Is a eharaoterlstla of load which accounts for Its usa In sene I Instances or takes It neosssary to take precautions In a era, 7or example, the softness of load is largely responsible for Its aiploynout ss a calking aaterlal* This property makes It possible to calk lead to fill the Joint saxpletely. Soft ness see mats, at least In part, for other uses such as in bearing metals, Da kota, mshart, laad handed sails aad tha Ilka, On tha ether hand, softness often makes It necessary to take BertaIn pre cautions In the use of load. In pipe lines, for examplo, high rolocltlos nay re sult In erosion, as 1 ham already pointed out, this is smotlmos ollalnatod by Increasing the also of linos to roduss velocity or by Imeronslng tho wall thle^ bo s s to compensate for erosion lossoe* <39P!P V' LIA16171 i" ' > ~7i <dTii*4iftaf>ia*V .***|^*iAd''*i I' * ! *'i itili i *ami.ii it-- rn i* * ~ r < ' it Tr*-- - - V------~ "1"- ..|r- v ------------ ---------------------------------------------- ------ -------------------- ------------------- tha softness and tendency at lead to sold flow rtl(H probiana la acnnaotlen with to* u** of load gsckata and wether*. The load whlah a load gaiket aaa carry without axooaalro flow la dependent upon several fa ator* whlah laeluda th* thlekne** of the mtel* the roughs*** or aaootisiaai of th# surface* between which tha piakat la placed and tha tacpcreture* la particular It should ba rataachorad that tha thlmor tha gasket oan be node tha greater will bo tha load It eon taka and tha laai artll ba lta tendenoy to flow. Alo, tha aaoethar tha surface between which It la placed and tha higher tha tmperetur* tha greater trill ba tha tandanay of tha laad gasket to flaw. la an example of tha mllaebillty of laad wu have lta ability to ba rollad to thin foil which la an inpcrtant easttraUl application of laad. It la quite canted/ rollad to thlaknoaa of 0*0006* and sonetlat* to even about half that thlakaaoa* fc | I Tho oharaatarlatlo flaxiblllty of laad la an Important contributing fee- ter It nr.r.y df Iti nddd. rrdhnbly tie **v`.ll* *Ma^>l ia la u ia or laad for eabla aheathlng which perult* tha aabla to ba aoilad and bnt aa da- alrad. Tho aaaa oay ba sold of lac.d pino In anny application*, particularly la wotar service plpo lino* wharo It la poitlblo* without a-hing Joint*, to bond goo*neoka integrally Into tho pipe ond to bend tho plpo around obatneloe* Otbar utoa whlah dupond to a largo cortunt on flexibility oro tho uao of land aa o '* for rubbor boao end load oollap*lblo tube* for paint color*, gloo and ethor jin a tla or a col-plnttie ooepound*. Horcrcr, too auoh liberty ahould net bo trim 0 with loadt* eharaotcrlatla of flexibility aa load ropoatodly floud will ovootuclly fall. load haa one of tho lotroit aoltlng point* of tho econen notala* tho sclh. lag point being NT,4 C, or 621 7. Thi* property of load* and particularly of lta alloy** rotult* In It* uao for aany purpose* eueh aa aoldor and fualblo al loy*. it contribute* to aany other* *uoh aa easting and typo Ktal by ^king tho manufacture and u*o oaiy. It la often a di* .er.ntago, an In ahoaloal oqulpnnt, where laad *u*t ba confined to u** In roiativoly low taparmtura operations* Harrrwr, In tha Uttar oaaa* tha disadvantage my ba ultlgated to aaaa axtant by proparly iupparUng land with ethor mterUla or eatuelly bending It to ataal Tor support* Tha frt that land haa both a 1h ultimate tana 11a atoaagto and law are ay atrongth nut alnoat always ba eoaildarod In applying laad aax&erelally. let almy* doaa tola proparty aaka any dlffaransa* but noro often It does. Evan whoa atrangth la a fuotor, horercr* tha low strength of loed dooa not nacaaaarlly praaluda It* u j *. load produot* oan ba d#*igned to that laad will ralnforaa italf, or In*art* or *upports of other uattrial* can b# provided. Alloying with aortaIn other metals* notably antiaenjr, la a cotton nathod of strengthening load* But In neat u* of laad* adequate *u: port abould alwaya ba kept In nlnd* Thu* horl* octal laad plpaa are usually oontlnuwialy supported and vortical plpaa at fre quent intervals* aa 1 have said. Shaat laad linings In deep *-ta *ra supported by fraquent laad aavarad ataal straps* afciHW-ia'ai LIA16172 -----------------------------------------------.*-------------- ~--'---- ----- ---------- ------- -- The ultlmte tensile strength ef tones load is 1400 to 1100 IK. par eq. in. sad of ehanloal load Is 1300 to *800 It. par sq. In. On the other hand, the ultlasts tensile strength of a 7f entlnony-leed alloy la ia tha neighborhood of 720 It. par sq. la, Bowrrer, the strength of tha aatiaonlal lead alloys falls off nore rapidly at temperature lnorsaaat so that at high taoperaturet tha antisocial load alleys hart little or no advantage erar load. Creep strength Juwrarar Is area sore Important than ultlsnte tossllo strength. COO It. per eq. in. It usually eonsidered a proper value to use for tho areop strength ef land in moat oasusreial applications at noranl taopamtures. The faot that lead has good self-lubrieeting properties results is a amber of eaaeereial epplloetieaa. As a eoating on airs, it lutrloataa droning dies, and at a coating on sheet nefc.l It alto aota,ns a dreeing luhrioost. Used in poedar or eire fora it lends proper lubricating properties to friction aatariale Ilka broke linings, snd os a poedar It is snployed in beery duty lubrlooting greases and in pipe Joist eoapounds. Tbs relntlrely hi A ooeffiolent of theraal expansion of load la another property which suit be kept in Bind ia aaay of lead'* uses. The linear coeffi cient of expansion is 0.000C2S3 per C. Tha isoraosa la voltaee fron C0 C. to the liquid at tha Belting point is 6.1 and tho shrinkage of easting at taken in praotloe as 7/64* to 5/1C* per ft. Tho 1inoar expansion is sore than (Of greater then that of copper and sore than teles that of iron. This high expansion rata naturally creates problem, yor instance, in pipe lines subject bo vido teifri ture variations prorislon Bust be Bade for free expansion. In roofing the lead has to be used is relatively snail sheet* which aro loose looked and not soldered together to a* to lialt tho expansion to any ano shoot and provost a ounulativa offeat en tha other hand load has relatively lev eleotrleal and heat oendactivity. The relative eleetrieal emduetaaoe of leed is 7.82 when copper is tekan as 100. and tha relative therael conductivity Is 5-2 whan silver is tekan as 100. Tho lor electrical conductivity ney soaetines have advantages. For instance, lead pipes buried in the ground are less ept to be eleetrolytloally corroded by stray cur rents sines the poor conducting lead is not apt to pick up these stray currents so readily as better conducting aetalt. The low boat conductivity, on tha other hand, nay scnetlses be a disadvantage particularly In chealoal eculpaeat where load is used In hoot exchange ooils. This is a ninor disadvantage however as it Barely affects the Initial rate of heating and cooling and ins little effect after the desired teoperetura has been ratobed. 1 nentloned lead's ability bo alloy with certain other artels in alnort any proportion and Its inability bo alloy with other*. Antlacny and tin are tha noet portion!y saployed alloying aetals. Antimony Is generally atplcyed to give greater hardness and strength as in torage battery plates, sheet, pipe and east ings. Tin also incroates hardness and strength but the lead-tin alloys are moat ecoaonly used for their welting characteristics as in solder. Tin in this sass and in terns netal and other lead alloy aoatinge also iaparte the ability to bond PWWW.WWJl'PllI -^'WMWjWWI^ ..... -, iUi.TB'liS^iirit l^W-||* i LI A16173 10 v 0 with metale Ilk* steel and copper, whloh lead alone poetesses only la a mil degree, 11a and entlacny both alio improve the oaatlag q.a.1 ltles of lead. Bt*auth la often alloyod with laad to obtain, usually with tin too, tha extremely low melting alloy*, although laad deai not alloy roadlly with eepper, It la *c bbleed in rather high percentages with copper in oartain boaring alloy*, and la frequently uaed In smaller poreontages in bronze* and free aaehlnlng braes**, Likorlee, though lead la difficult to alloy with atoal, it 1* employed In frastiacal porecatagoe in fro* Machining steel. Calelua, Bognosiw and aodiiaa in fractional percentage* are cometlm** alloyed with lead in apeolal bearing alloje and oable aheathing. Cadalus addition* to lead haw* been found helpful in eoatlng copper wire* with lead. In gcnaral, lead ueually alloy* quit* readily with oat of the whit* Betels, and despite the greater difficulty of alloying with copper and steel. It la frequently uaed with those Betel*, X Bore detailed dlaouaslee of these alloys would virtually constitute a subject In Itself since the variety of compositions used 1* treeendout. The Boat enldM> tr* -- <-- JO* tin---- * K* l~d, ***** *"*- -- * 1 60JC lend. During tbs war whon tin was so aeareo It was necessary to reduce the tin oontent of adder* considerably and soldare containing 20 or tOf, tin only were widely enployed and in scat eat** successfully, however. In general there ha* been a return to the higher tin oonteat soldera because they are aaeier to handle particularly In hand aoldaring operations. In aachine soldering opera- tlone, however, eueh as In the earning industry the lower tin content a older* ap pear to have worked eatiefaetorily after adjusting production aothoda to the higher tempos-* turee and wider plastic range* that they handle. Sena soldere con taining up to a oouplo percent silver, with e aunll percentage, cr no tin, have boon used. They have the advantage of additional strength but the disadvantage of fairly high soldaring tet^eraturse. There ie on* relatively new field of ayplloetloa of Iced on ehloh I would Ilk* to spend a little tine, which has to do vlth It* alloying ability. That is the use of certain lead alleys for proteotiv* costings on Iron and steel. The aoarelty of tin, tino end ead&ltn for couting during the war led to a consider able aaouat of experimental work an lend a* o protective coating. Attests to use pure lead wore not satisfactory because of lead's poor ability to wet and al loy with tho stool haso. it was found, hewaver, that highly satisfactory seat ing* eould bo applied if tha load wore alloyed with only relatively saall astounts of tin cr tin and antiaony and os a roiult a considerable tssount ef load alloy eoatod stool wae usod for sush purposes as polo lino berdsoro end radio ehassle. Currently th* nost popular alloy* being used, aside fron the eosvcBtienal tens* plate which hat been knara for nany years and which oontaine fraa 12 to 20J. tin, are t laad plus 7% tin and load plus 2-2-1/21* tin and 2-2-1/Zf antimony with acactiaes a fraotlco of a pereast of ailver. Several nanufaetvers are using thee* alloys to ooet produet* eueh as roofing hardware, automobile gasoline tank spout* end far saall artioles, Several plants bar* been set up to do hot dip lead alloy coating on the Jobbing basis far others* 3 *bp-u ,,niayiwiip-,1'^,'/ whWBg wr PpNfNpoi* i I t{ i j i k wthhtaaM mmwmnmm. LIA1617A -------- r---------:------ ---- * ------------------------"'ll ----------- "' "' ' One deterrent to tha adoption of load or load alloy eoetinge la earlier year# ai tho pro t o Io h o o of pin holoa la thoao e Dating*, Ko w o y o r# work doao during tho war doaonatreteo that ualag tho proper fluzaa and alloy tho pin hoi Of oosild bo alnlniaed and that aueh pin boloa at there woro In tho ooetlng did not affoot lta Ilfa. While thoro nay bo acoo initial mating of load coated a tool ao a raault of that a pin helaa It hai boon found that tha pin holt* ara aalf-aoellng and ruetlng dooa not procood beyond tha initial at&go, tho maty appooranoe ac tually dlaappoarlng In tlao. In other word*, load eeatod a tool that li expoeod to tho otaoaphoro or to oalt apray taata look* bettor aftar a foried of expoaure than It doaa In tho initial i to roe of expo* ure. To gwt equal protection with load alloy ooetlng* aa eeoparod with teat ether kind of Mtalllo ooetlng, It la generally agreed that a lighter ooetlng ay ba utad and the coating haa aorwrm.1 otier edrentaga*. for Inatanee, a lead coating prorldea an Ideal baa# for paint without any apeclal preparation other than to reaoro oil or grace* frca tho aurfaoa. lead oral >*. ateol artidea aay bo readily oeldored or woldod. T aaronn y Innlr fn* a- .*i **-- noo of load alloy eaatlnga aa tho aothoda of applloctlcu and their virtues beo m better known* .jwp.. .-Ill w I