Application of ASTM A860 WPHY fittings in ASME B31.3

The “wrought pipe high yield” butt welding fittings made to ASTM A860 can be applied to process piping that is designed in accordance with ASME B31.3. Six steel grades for ASTM A860 fittings are available: WPHY 42, WPHY 46, WPHY 52, WPHY 60, WHPY 65, WPHY 70. According to the Code, the design minimum temperature and design maximum temperature for all WPHY grades of ASTM A860 are -50°F and 500°F, respectively, except that the design maximum temperature for WPHY 70 is 400°F.

An ASTM A860 Gr. WPHY 60 barred tee, 20″ SCH100, dimensions to MSS SP 75, both internal & external surfaces black-painted, supplied to Italy.

For design purpose, temperature-dependent basic allowable stresses in tension for each WPHY grade of ASTM A860 have been specified in Table A-1 and Table A-1M of ASME B31.3. Allowable stresses in shear shall be 0.80 times the basic allowable stress in tension; Allowable stresses in bearing shall be 1.6 times that value. Allowable stresses in compression shall be no greater than the basic allowable stresses in tension.