Hastelloy C-276 fittings manufactured to ASTM B366 Gr. N10276 can be furnished in either seamless or weld types. Its nominal composition is 54Ni-16Mo-15Cr and the fittings shall be solution annealed. The fittings can be used for a plurality of applications based on ASME Boiler and Pressure Vessel Codes. Generally, these applications can be classified into two conditions: Condition A & Condition B. Condition A refers to Hastelloy C-276 fittings used for ASME BPVC Section I, Section VIII Division 1, and Section XII. Condition B refers to Hastelloy C-276 seamless or welded  fittings used for ASME BPVC Section VIII Division 2 respectively. The maximum allowable stress of ASTM B366 Gr. N10276 at elevated temperatures are listed in below 3 tables.

1. Maximum Allowable Stress of Hastelloy C-276 Fittings in Condition A

*Temp.	-20~100	200	300	400	500	600	650	700	750	800
*MAS	27.3	27.3	27.3	27.3	26.9	25.2	24.6	24.0	23.5	23.1
*Temp.	850	900	950	1000	1050	1100	1150	1200	1250	-
*MAS	22.8	22.6	22.4	22.3	18.5	15.0	12.2	9.8	7.8	-

*Temp.: metal temperature, °F, not exceeding; *MAS: maximum allowable stress, ksi. For both seamless & welded fittings.
*The maximum applicable temperatures of Hastelloy C-276 fittings for Section I, Section VIII-1, and Section IX shall be 1000°F, 1250°F, and 650°F, respectively.

2. Maximum Allowable Stress of Hastelloy C-276 Fittings in Condition B

*Temp.	-20~100	150	200	250	300	350	400	450
*MAS-1	27.3	27.3	27.3	27.3	27.3	27.3	27.3	27.3
*MAS-2	23.2	23.2	23.2	23.2	23.2	23.2	23.2	23.2
*Temp.	500	550	600	650	700	750	800	-
*MAS-1	26.9	26.0	25.2	24.6	24.0	23.5	23.1	-
*MAS-2	22.8	22.1	21.5	20.9	20.4	20.0	19.6	-

*Temp.: metal temperature, °F, not exceeding; The maximum applicable temperature for Section VIII-2 is 800°F.
*MAS-1: The maximum allowable stress of Hastelloy C-276 welded fittings at elevated temperatures.
*MAS-2: The maximum allowable stress of Hastelloy C-276 seamless fittings at elevated temperatures.