. Tentative revised boiler safety orders. bottom of thread, less .0276 sauare inches Allowable load at 7,500 pounds stress per square inch 4 -- 16 - 8 - l__ J-16 J-s - 1 _3_--16 l-S. -^1613/ -^s - 1 _7_//-Ll6 ±2 - 1,9532,4252,9353,4984,1054,7655,4556,2056,9937,8338,7189,64010,623 Note.—Area 3/16 hole = .0276 square inches. For permissible loads onsolid staybolts, see Tables 11 and 12. TENTATIVE BOILER SAFETY ORDERS. XIX (c) The maximum allowabl
. Tentative revised boiler safety orders. bottom of thread, less .0276 sauare inches Allowable load at 7,500 pounds stress per square inch 4 -- 16 - 8 - l__ J-16 J-s - 1 _3_--16 l-S. -^1613/ -^s - 1 _7_//-Ll6 ±2 - 1,9532,4252,9353,4984,1054,7655,4556,2056,9937,8338,7189,64010,623 Note.—Area 3/16 hole = .0276 square inches. For permissible loads onsolid staybolts, see Tables 11 and 12. TENTATIVE BOILER SAFETY ORDERS. XIX (c) The maximum allowable stress per square inch net crosssectional area for various kinds of stays and staj^bolts is given inthe following table: Material and type Si/e up to and incluJins 14 diameter or cQuival-r^nt area Size over 15 diame-er or equivalent area Weldless head to head or through stays-Iron Steel —_- Weldless diagonal or crowfoot stays-Iron Steel Welded portions of diagonal or crowfoot staysIron or steel Mild steel or wrought iron staybolts. 8,0009,000 7,5008,000 6,5008,000 Note.—14 diameter equals square inches. 1379 Boilers of butt and double strap construction shall beoperated with a factor of safety of at least four (4) by the for-mula, paragraph 378 (a), until January 1, 1922, after which datethe factor of safety shall be at least four and five-tenths (). Inno case shall the maximum allowable working pressure on old boil-ers be increased, unless they are being operated at a lesser pres-sure than would be allowable for new bqilers, in which case thechanged pressure shall not exceed that allowable for new boilersof the same construction. *380 (a) The lowest factor of safety used for boilers, the shells or drums of which are exposed to the direct products of combustion, and the longitudinal joints of which are of lap riveted construction, shall be as follows: 4i for boilers not over five (5) years old. 4i for boilers over five (5) and not over ten (10) years old. 4f f
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectsteambo, bookyear1919
