Document np2va4eL44bRpX7Q5dr6ZYy68

TECHNICAL BRIEFS ENCtNEERlMC DEVELOPMENTS moo oiOEsrEo roe suit powu N(| j PIPING, SUPPORTS An Unusual Defect in a Boiler Support* by Fuleon Boiler ond General insurance Co. A 22,000-lb-per-hr steam-generat ing unit revealed on inspection a deterioration of the vertical web of tbe main girder, Fig. 1. This S ft, 2 in. girder is the built-up {section type, Fig. 1, filled with verticol stiffener angles on both sidea of the web. It spans 31 ft. One side opens on the boiler room. The other faces the fire, behind a sheet, metal easing that runs the length and width of the girder, leering a 6-in. air space between easing and girder. Fig. 2. The plate had no ventilating holes. Corrosion reduced the verticol web ptote at the upper part from % to % in. in many places. In a few places corrosion had penetrated the plate. The vertical stiffener angles on the fire side had been reduced to paper thickness or completely wasted away. No deflection of girder alignment was detected. For* tunately the girder, built lor 250-ton loading, had to carry only 70 to 60. Two samples of acole and dust were taken. Both showed oxides of iron snd were strongly magnetic. There seemed to be no trace of acid. The second sample did show silica, apparently (tom Rue gas. To prevent a recurrence an air space in the fire side of the girder hss been provided. Plates 14 in. thick fora the casing. They ore protected by a 17-in. refractory wait. Several L-in. holes drilled in the web plate of the girder allow ventilation within the air apace. Sight holes, 9 in. dU, have beeo cut In for inspection. Fufcan Magazine, July 1947, pp 145-147, Vulcan Boiler and Central Insurance Co. London, England. A Study of the Properties of 0.5% Chromium--0.5% Molybdenum Pipe Steel, by R C Filigemld, Consolidated Cot Electric Light & Power Co; A B Wilder. National Tube Co; C V Smi/A, U, S. Steel Corp; and A E White, Uni* vanity of Michigan. Since the occurrente, early in 1943, of severe local grsphitixatten and failure of a welded joint ol molybdenum steel In a high* pressure steam line st the SpctutahvStation of the West Peno Power Ctflf' metallurgists and engineers biv pended considerable effort in stadyi.* the fundamental lacton involved b (feflfc reversion of corbide to graphite, developing alloys and manafictnjW practices that will inhibit the fartu^ of graphite during commercial ougg,! Of the several changes propot&.w minimice or prevent graphititsUoa, foiinvolving the alloying addition ol chrt miuat has generally been considered d* most effective. The cooperative nsij reported in this paper was undertsko to test this possibility. An stbitru) chromium addition of 0.5% (to Up 0.5% molybdenum lvel commonly cued for steam pipe) was selected. Two heats of commercial she, wttd cannot always he approximated by small experimental or laboratory bests, were employed for the tests. These west rolled into 1094 in- by 1.)25-ir.-w*fl seamless pipe. The two heat* wett tietiInally identical except for the deoxida tion practice employed, one being midt to coarse-grained, the other to fine grained practice. The cosrss-grilstd ... cross-sections and construction details included in new Johns-Manville Goetze catalog 8*rt vnp master tfvf/ Mgl/tBuilt-up Uoetlon (obovo) is tha main girder. Corrosion reduced vertical web plate to ft In.; wottod stiffener* Tits kaMDy reference chore nhown above is one of many feature* of the mechanical strength and resilience . . . the Qoetze V-Tite, a special solid metal aev )-M Ooetze Oasket catalog which gasket for sealing ring type joints ... as make it easier for you to select metal well es the many styles of boiler, cylin piksts. It gives cross-sections and con der head and heat exchanger gaskets in struction details of more than 30 basic the complete Ooetxe line. Cort/f Qajket designs that ere available In fact, there isn't on important metel Bern to meet your requirements. gasket development which is not cov Here, too, you will find complete de scriptions of such noteworthy developraents as the Goetze Beltowwal--the P&et with the automatic self-sealing ^jaruion joint for high temperature, tyh pressure service . . . the versatile Spwotallle with its combination of high ered--or a single metal gasket problem to which the new J-M Ooetze Gasket catalog won't help you find a practical, money-saving answer! If you buy or use metallic gaskets, you mil want to hove full information about these latest Goetze developments et your finger tips. Write, on your company letterhead, for your copy of the new Ooetze Oasket catalog. Address JohnsManviUe, Box 290, Nay York 16, N. Y. SEND FOR YOUR COPY TODAY TbaoewOoetMQuket Catalog containing the handy gasket reference chart shown above hes *8 page* of up*to theminute gaeket Infor mation. Write for your copy today. 2 Main girder (right) opens on the fire $ldo behind o metol casing. Poor ventilation plus ftuo gos ato away the girder 128 (184) iohns-Manville^p Gaskets 'CtWEg