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ASME B31.3-2016 shall be suitable for the manufacturing or fabrication 306.3.2 Miter Bends for Category D Fluid Service. process and the fluid service. A miter bend that makes a change in direction at a single joint (angle a in Fig. 304.2.3) greater than 45 deg, or is 306.1 Pipe Fittings welded in accordance with para. 311.2.1, may be used 306.1.1 Listed Fittings. Listed fittings may be used only for Category D Fluid Service. in Normal Fluid Service in accordance with para. 303. 306.3.3 Miter Bends for Severe Cyclic Conditions. 306.1.2 Unlisted Fittings. Unlisted fittings may be A miter bend to be used under severe cyclic conditions used only in accordance with para. 302.2.3. shall be made in accordance with para. 304.2.3 and welded in accordance with para. 311.2.2,and shall have 306.1.3 Specific Fittings an angle a (see Fig. 304.2.3) <_22.5 deg. (a) Proprietary welding branch outlet fittings that 306.4 Laps have been design proof tested successfully as prescribed in ASME 1316.9, MSS SP-97, or the BPV Code, The following requirements do not apply to fittings Section VIII, Division 1, UG-101 may be used within conforming to para.306.1,specifically lap-joint stub ends their established ratings. conforming to ASME 1316.9, nor to laps integrally hot- (b) The lap thickness of a proprietary "Type C" lap- forged on pipe ends, except as noted in paras. 306.4.3 joint stub-end buttwelding fitting shall conform to the and 306.4.4(a). requirements of para. 306.4.2 for flared laps. 306.4.1 Fabricated Laps. A fabricated lap is suitable (16) 306.1.4 Fittings for Severe Cyclic Conditions for use in Normal Fluid Service,provided that all of the (a) Only the following fittings may be used under following requirements are met. severe cyclic conditions: (a) The outside diameter of the lap shall be within (1) forged. the dimensional tolerances of the corresponding (2) wrought, seamless or welded. If welded, ASME 1316.9 lap-joint stub end. requires 100%radiograph of welds in accordance with (b) The lap thickness shall be at least equal to the para. 344.5.1 and Table 341.3.2. nominal wall thickness of the pipe to which it is attached. (3) cast,with factor E, >_ 0.90.7 (c) The lap material shall have an allowable stress at (b) Fittings conforming to MSS SP-43, MSS SP-119, least as great as that of the pipe. and proprietary "Type C" lap-joint stub-end welding (d) Welding shall be in accordance with para. 311.1 fittings shall not be used under severe cyclic conditions. and fabrication shall be in accordance with para.328.5.5. 306.4.2 Flared Laps. See para. 308.2.5 for require- 306.2 Pipe Bends ments of lapped flanges for use with flared laps.A flared 306.2.1 General lap is suitable for use in Normal Fluid Service,provided (a) A pipe bend made in accordance with that all of the following requirements are met. paras. 332.2.1 and 332.2.2, and verified for pressure (a) The pipe used shall be of a specification and grade design in accordance with para. 304.2.1, is suitable for suitable for forming without cracks, surface buckling, the same service as the pipe from which it is made. or other defects. (b) A pipe bend made in accordance with (b) The outside diameter of the lap shall be within para. 332.2.2, but not meeting the flattening limits of the dimensional tolerances of the corresponding para. 332.2.1, may be qualified for pressure design by ASME 1316.9 lap-joint stub end. para. 304.7.2 and shall not exceed the rating of the (c) The radius of fillet shall not exceed 3 mm (%in.). straight pipe from which it is made. (d) The lap thickness at any point shall be at least 95% of the minimum pipe wall thickness,T,multiplied 306.2.2 Corrugated and Other Bends. Bends of other by the ratio of the pipe outside diameter to the diameter designs(such as creased or corrugated)shall be qualified at which the lap thickness is measured. for pressure design as required by para. 304.7.2. (e) Pressure design shall be qualified as required by 306.2.3 Bends for Severe Cyclic Conditions. A pipe para. 304.7.2. bend designed as creased or corrugated shall not be 306.4.3 Forged Laps. A lap integrally hot-forged used under severe cyclic conditions. on a pipe end is suitable for Normal Fluid Service only when the requirements of para. 332 are met. Its dimen- 306.3 Miter Bends sions shall conform to those for lap-joint stub ends given 306.3.1 General. Except as stated in para. 306.3.2, in ASME 1316.9. a miter bend made in accordance with para.304.2.3 and 306.4.4 Laps for Severe Cyclic Conditions welded in accordance with para. 311.1 is suitable for (a) A forged lap-joint stub end in accordance with use in Normal Fluid Service. para. 306.1 or a lap integrally hot-forged on a pipe end