Document dYa3gLBeNR3xJ1B48dLmZX796

imp w w w w h LI APgci^c V-'IK'/. Li..-- Lit* a^OSsUCT* Dhn*OW mto ur srzv, IK Tu-dC IT, M. T. March Jl, 1950 r'. r,"".i r% & O i l ? ; *~i 7.t nsnars of d.rld.-d lnterr rt to ths lead itv.' Jry were presss/ted rt tN Jt.-- 'V tj 1570 *r-r'.7r 3 of the L.t r\*S* &t'.tioa oi t.~.d Society of Keval jrchiu:v end iiainteiuiCd answers. T.-.d psper-a cor* artdtledt Hecent i-xperiar.coi with Corwriaa and E-cita-e of Copper '' irc-ulatin^ Piping la Ship1* tiihi&sry Spaces* by 3. C. Warliillaa, chief engineer, Cec-rje 0. Sharp, *awal archi tect, and "Conation of Copper Piping in S*lt Wator Serrio*" by Tm>1 .field, superintendent of derolopsar.t end reaearch, Shlpbtildini Dlrielon, BeLhlahsa Steel Compnj. Followin: ere of the ealient feature* free thee* paper*. Thmj *111 be of pertlculer lat-orta-ic# to thoae lnteroatod In learning about the actual performance of co.-per In eelt ater eerrlce and ho* leeo alloy nay be used to overcoat lta deflcieodee, srtLlflc cadi KDTORia The operator* of "C* type carpo ehip* **r* and In aery caji tlll are experiencing Cu.-valdiraule trouble and erpenee due to tr* rapid of copper circulating pipe, Tr.ti protlea la an especially ieblou* ora for on nary of the.it a ilpa portions of vht auxiliary circulating ay a ten cannot be reached or replaced ur.it)j tie entire elactricai plant la put out of operation. T.tl* a*an* that the repair* eurt b* don* on a pieee-w&l baa la In order not to Interrupt th* ar.ipa cheJule and careo cowdtecnt*. Jn# owner ha* reported that tne repair of oop.-t-r circulating piping 1* tne larjeat Itea of maintenance on bis *hlpe. Here aro to typical case niitorlei quoted fro* ^acUUan'a paper. Case Wodbcr 1 * CJ eilp had 6 **etlonj of copper plptn( varyir.i free 6 to IL lnthae In diameter and fro* 8 to 12 fit in length repsired a;,Tro*iataly three end ne-iialf ye it * after cooBiulin. :.t IM* tin* lv>e aectlona were rt -iv;!, aard bleated nj *i th lead 0.0L5 ir>c(.* thick and th-n aprtyed with a la.-.5te flniah. Since this treatment th* ahlp ha* been in ereioe about one year and ha* jln no further troubl*,* 1 wmmmmm LI a r q c 5 g w --CTEsncja. 3osisrrs-soi- ~ " - * -"" March 31, itfo o Q O CtM Ihigber 2 l C3 Mp h* bo*n In eoT-aTCial serrie* alnee eocsrclsrionint and after approxtrvteiy t*i yews of opt-r<sti*jn began to experience trsuol* with c-rj.-r cirrulatIn? piplnc* Til* a hip, like W-V others built durlr." tw wir irrei'. ately tVrrt-titer *** fitted with eopp-er circulatin' which r.re u.iti.-.r.'d and rut with lcid or aol-l'T, Inter: .1 r Inaticn r .* 1 nu rr-? spot# of various else*, frcs tiny pit*.:.to tr*u 1/2 ir.th In <Hefc<tt, eroiai to * pej~r- thin tMcfcrve:*. it tV.s tire, en* now e--ction of 6 Ir.ih dinrt'.ter eurilitry i.sch&rga piping as renewal with copper pip* tinned and la*. wiped. Two mont'.s later, too t*o retaining sections of 8 Inch piping were renewed witn copper pipe whicn nod been tinned ana lead wiped t .reughout to e thickness of 1/3 inch. Tour north* later, or thlrty-eigit conths after connls*ioning, the 1? inch dia-wet'T coabined odeehirgo frao tn* 6 inch line w*j leaking t>adl/ and had to be renewed, ..1*0, the first piece of 8 inch Jlsciarpe line IMt has been renewed fourteen eonthe previous ly la now .taking at three locations, .'.is piece of 8 inch renewed pipe as examined Intcrr.aily and extomaiiy and at ail tore* leaks, lea. llni:^, tinning and copper ^a.i had broken ao.-n. In three otner locatij.-j on tna bottan side of tns pipe, the copper was checked i.u vory hard, probing these t iree areas alto U blade of a pen knife, ,n corV-r wall Is easily ponatreted. However, t >j lead lining spoored in good condition, toe holes were plugged and the 30 psi cold -tcr test waa allied. Ho looks appeared at ths points .here the copper was penetrated by tn knife blaia,* Corrective Miarurea Tried and Tasted In practice.ly all ca?s itcjr wrj taken to insure that th cause of these failures was not duo to electrolysis* In soac operetors' opinion* the dsnare w*s c %j j ,i by a ecMnation of hlch velocity and the presence of entrapped eir. Tny tri.d vnrioua oih>ls of eliBinatln.* th> air and reducing erosive action but it (till did nit step the trouble. I/onol piping has beer tried and app< or* V> p.-rfera ruce. .sfuliy but la prohibitive coAtwise for o,t opjrstors. hubhor linings a d rub'ewr lined stool has also oeen need. Tnc cost of the rubber liking n l Including Oita! pipe and flange* is about el5 per foot for 21. inch pipe# plus euS fjf pair cf altec.wd flangv*. Cop,, ir c^tpatles do rot rncomervi that copper pipe be rubber lined unless .hi tt^rulv. /r,t * tic rubber, neoprene, can be asodU jpariy Paijur'S h t~rt-'d, C'll* r Call'd "Ov ir-ratod* The author of i*<; s.*c ed pap.>r point* out witn quotation* free worliar literature t ut failure* of eo.jp^r piping in .* water have been in evidenc for as v year* as piping has b-evo u>i fir this particular e-rrUe. Ho do - sci it.s in detail ,s,.*ritne<i of tw. Ixp^nal German l*vy during too period iOyd- 1V0J. CKSaCj& FJ-i-IvTlS *0. 31* J lurch )l, 19$0 Or tbs bull of post performance, ffield has this to sayt Copper la * isott versatile ftcud and It has nary desirable ehnrarverintic-, U 1 enact m thAi^h it ia aieo the Bolt rvtrraied et.u-rit.1 far eH **ter piping or snipe. It baa a niaut-y cf tin; cf-'iia eorT.ee to to* print w.iere it can only tn dassod ts w'tii-.*:'!# wines it racelva suitable protection** Marry Crash t a.v.1 Cure a Investigated Tno author oiaevsfM in so# detail tha effoots of and exp-rleneee with electrolytic, cavi_.:i :r<<ta, effect of now and o*rlioo and eouUainatio by bll*> water, list.v;., that t.:# boon triad fir protecting t o copp-or, in ftost easts by fonslnj a protective fils, eere not too euee**cful* Thee# include tepr.alt, Hard rubber, plus, writ** glue, lie tic 1acquere, ate. Sacft sehanea failed and aero discarded because the fllaa wero eubjoct to daaye and contrlbated to valve fallurvj. Other stteapta at elec roly-tie protection were unsuc- euafal, toad-Tin alloy Offers Boat Solution fhla la what the aather had to ay about ualng lead-tin alloys for protecting copper* "ill eoppor piping for aae with aalt water should be lined with lead-tin for its protection, alth proper application reaulta ar* good although aswe of the earlier investigators felt otherwise* a 60 par cent lead and 1*0 par cent Un alloy ia generally used* "There are to netisoda of applying load-tin coatings to copper, naaaly b/ hot dipping and by wiping* In trto forear, a very thin (a;>proxijMt?ly 0*001 In.) coating is applied by dipping the object in i turn of wlten laid. vri carre ding con-^lUar.s are tcVvrw, th*-e dipped coatings are of questionable protective value because the le-o-tln coating becomes contanlnatcd or alloyed with the Capper, unfortunately, eltrair toe lead-tin-copper alley or its carraslan f11a is cathadlc to tbs baso copper aid will cause gal vanic corrosion if pinholes occur In the coating. Furthurnore, the highor toe teaperaturo of tbo bath, tho greater will be the alloyln effect of copper and des,*to cart in balr.talnLng the bath at t.v> lowest practicable tsnperaturc, t ealten cUi will be continually picking up copper and thus Contaminating the bath. Coatlr. s applied by to dip preeees are Inadequate for the protec tion of copper* *ipo4 costing* are fenwd by torch heating tha copper and tSa levd-tln r.lxture to a Wesporsturw at which tho lead-tin alloy la not nalton out le nuefy* In it* ftu*h/ etete, this alley can be spread and wiped on tha enpp-ar to a thicknora up to 0,1 ?S inehaa* while tv.ro 1* a ftlnor alloying effect at tha borvd blen this coating and the copper, tha cnjp.r-rleh alloy It very thin and OE3SCAL BUUrmt BO, 3k k lurch 31, 1?$0 csrieVtly eorarwd by a fens* load-tin coating. Tb aacoBta*inatcd coiling la anodic to eopper aM effort galvanic protection aa wii ai hiring good raaiataoea itaalf to tut tlowing aerated aa water.* Seoulta of Anparlaonta Erperlnents ith nriou* type* of coatinga wrra conducted and tha reaulta compiled. "-> teata involved axpsoure to Jet Inplngasont by aaa water aad alao to varying rata* of flow. Thu reaulta My ba ausaaritod aa followet a. Olp coating* do wore bars than good. b. wiped coating* afford ccaplate protection. e. Slaty per cant load - kO per cant tin la tha bait alloy, d. oprayod load coatlnga look good. o. Toe aavarlty of attack iocrttMi with laerwaaing tenparatorn* Service experience haa confined *n** *b* and *n* bet Pfiald baa bad no experience to corroborata *c* aad *d* In hia c j relation tha author rtataai The work of cthara and tw author'a afforta to atan oopper aill water pipe corrosion point to only ooe conelullon for thin piper, neatly, copper la vaulted* for aalt eater aarrlca onleaa tt la protected ty leed-tln ipir*.* Conduct on Thorn ara obviou* Inconel* tens lea and ineocclutlve rciulta In aoaa aectlon* of theta papart, a* Intend to nakt further lr.watlgationa to clarify tha situation. Keverthelesa it la conducive that coppar alone deal not girt tatiafactory aorrice In tilt *<l~r and mat to* utn of laid definitely doaa Uprora tho porforameo and lncraaaa aarrlca Ufa. It la under* tood that tha nagatlna r*eeifle Varlna Review* plana to publlfh either In atatract or in full both of the above paper* in thatr Barch ixau*. *Krino So* aagailn* plana to fwbllah ona of the paper* in their vrll icrua. In either ca*a, the Aaaocletlon plana to obtain reprint* for tha benefit of its aeabtn,