2021-06-24_REVISION - M2012032 - Laserfiche WebLink

Home Browse Search

ASME B31.3-2016 (16) 308.2.3 Socket Welding and Threaded Flanges. A may be used with nonmetallic gaskets in flanged joints socket welding flange is subject to the requirements for rated ASME B16.5 Class 300 and lower for bolt metal socket welds in para.311.2.5.A threaded flange is subject temperatures at—29°C to 204°C (-20°F to 400°F),inclu- to the requirements for threaded joints in para. 314. sive. If these bolts are galvanized,heavy hexagon nuts, 308.2.4 Flanges for Severe Cyclic Conditions. Unless threaded to suit, shall be used. it is safeguarded,a flange to be used under severe cyclic 309.2.3 Bolting for Metallic Flange Combinations. conditions shall be welding neck conforming to Any bolting that meets the requirements of para. 309 ASME B16.5 or ASME B16.47, or a similarly propor- may be used with any combination of flange material tioned flange designed in accordance with para.304.5.1. and facing. If either flange is to the ASME B16.1, 308.2.5 Flanges for Flared Metallic Laps. Fora ASME B16.24, MSS SP-42, or MSS SP-51 specification, flange used with a flared metallic lap(para.306.4.2),the the bolting material shall be no stronger than low yield intersection of face and bore shall be beveled or rounded strength bolting unless approximately 3 mm (%in.). See also para. 308.2.1(c). (a) both flanges have flat faces and a full face gasket is used, or 308.3 Flange Facings (b) sequence and torque limits for bolt-up are speci- The flange facing shall be suitable for the intended speci- fied, with consideration of sustained loads, displace- ment strains, occasional loads (see paras. 302.3.5 and service and for the gasket and bolting employed. 302.3.6), and strength of the flanges 308.4 Gaskets 309.2.4 Bolting for Severe Cyclic Conditions. Low Gaskets shall be selected so that the required seating yield strength bolting (see para. 309.2.1) shall not be load is compatible with the flange rating and facing,the used for flanged joints under severe cyclic conditions. strength of the flange,and its bolting.Materials shall be 309.3 Tapped Holes suitable for the service conditions.See also Appendix F, para. F308.4. Tapped holes for pressure-retaining bolting in metallic piping components shall be of sufficient depth that the 309 BOLTING thread engagement will be at least seven-eighths times the nominal thread diameter. Bolting includes bolts, bolt studs, studs, cap screws, nuts, and washers. See also Appendix F, para. F309. PART 4 309.1 General FLUID SERVICE REQUIREMENTS FOR PIPING JOINTS 309.1.1 Listed Bolting. Listed bolting is suitable for 310 GENERAL use in Normal Fluid Service,except as stated elsewhere Piping joints shall be selected to suit the piping mate- in para. 309. rial and the fluid service, with consideration of joint 309.1.2 Unlisted Bolting. Unlisted bolting may be tightness and mechanical strength under expected ser- used only in accordance with para. 302.2.3. vice and test conditions of pressure, temperature, and external loading. 309.1.3 Bolting for Components. Bolting for compo- nents conforming to a listed standard shall be in accor- 311 WELDED JOINTS dance with that standard if specified therein. 309.1.4 Selection Criteria. Bolting selected shall be Joints may be made by welding in any material for adequate to seat the gasket and maintain joint tightness which it is possible to qualify welding procedures,weld- under all design conditions. ers,and welding operators in conformance with the rules in Chapter V. 309.2 Specific Bolting 311.1 General 309.2.1 Low Yield Strength Bolting. Bolting having Except as provided in paras.311.2.1 and 311.2.2,welds not more than 207 MPa(30 ksi)specified minimum yield shall conform to the following: strength shall not be used for flanged joints rated ASME B16.5 Class 400 and higher,nor for flanged joints (a) Welding shall be in accordance with para. 328. using metallic gaskets, unless calculations have been (b) Preheating and heat treatment shall be in accor- made showing adequate strength to maintain joint dance with paras. 330 and 331,respectively. tightness. (c) Examination shall be in accordance with para. 341.4.1. 309.2.2 Carbon Steel Bolting. Except where limited (d) Acceptance criteria shall be those in Table 341.3.2 by other provisions of this Code, carbon steel bolting for Normal Fluid Service.