ASTM A266/ ASME SA-266 Applied to BPVC

Forged carbon steels conforming to ASTM A266/ ASME SA-266 may be applied to the manufacture of various pressure vessel components. These pressure vessel components cover heat exchanger headers, tanks, tube sheets, nozzles, and hubbed branches, etc, which are intended for ASME Boiler and Pressure Vessel Code applications. The ASME BPVC Section II Part D has specified the application of ASTM A266/ ASME SA-266 forgings in various Codes with maximum temperature limits and allowable stresses. There are 4 steel grades for ASTM A266: Grade 1 [K03506], Grade 2 [K03506], Grade 3 [K05001], Grade 4 [K03017]. The P-number and Group number are 1 and 1 for Grade 1, while 1 and 2 for other grades, respectively.

Applicability & maximum temperature limits

ASTM A266/ ASME SA-266	Max. Temp. Limit °F for Section
	I	III, CL 2 & CL 3	VIII, Div. 1	XII
Gr. 1	1000	700	1000	650
Gr. 2	1000	700	1000	650
Gr. 3	1000	700	1000	NP
Gr. 4	NP	NP	1000	650

*Table A-1; NP: refers to “not permitted”.

ASTM A266/ ASME SA-266	Max. Temp. Limit °F for Section
	III, Div.1, CL. 1 & MC	III, Div.3, CL. TC & SC
Grade 1	700	700
Grade 2	700	700
Grade 3	700	700

*Table A-2.

ASTM A266/ ASME SA-266	Max. Temp. Limits °F, for Section VIII, Div. 2
Grade 1	1000
Grade 2	1000
Grade 3	1000
Grade 4	1000

*Table A-3.

Allowable stresses at elevated temperatures

Temp.	-20~100	150	200	250
S1	17.1	17.1	17.1	-
S2	20.0	-	20.0	-
S3	21.4	21.4	21.4	-
S4	20.0	20.0	20.0	-
Temp.	300	400	500	600
S1	17.1	17.1	16.3	15.3
S2	20.0	20.0	19.6	18.4
S3	21.4	21.4	20.4	19.2
S4	20.0	20.0	19.6	18.4
Temp.	650	700	750	800
S1	14.8	14.3	13.0	10.8
S2	17.8	17.2	14.8	12.0
S3	18.5	17.9	15.7	12.6
S4	17.8	17.2	14.8	12.0
Temp.	850	900	950	1000
S1	8.7	5.9	4.0	2.5
S2	9.3	6.7	4.0	2.5
S3	9.3	6.7	4.0	2.5
S4	9.3	6.7	4.0	2.5

*Table B-1: maximum allowable stresses, S₁, S₂, S₃, S₄ for ASME SA-266 Grade 1, 2, 3, 4 respectively, ksi; for metal temperatures °F, not exceeding. Table B-1 is corresponding to Table A-1.

Temp.	-20~100	150	200	250	300
Sm1	20.0	18.8	18.3	-	17.7
Sm2	23.3	-	22.0	-	21.2
Sm3	25.0	23.5	22.9	-	22.1
Temp.	400	500	600	650	700
Sm1	17.1	16.3	15.3	14.8	14.3
Sm2	20.5	19.6	18.4	17.8	17.2
Sm3	21.4	20.4	19.2	18.5	17.9

*Table B-2: design stress intensity, S_m1, S_m2, S_m3, for ASME SA-266 Grade 1, 2, 3 respectively, ksi; for metal temperature °F, not exceeding. Table B-2 is corresponding to Table A-2.

Temp.	-20~100	150	200	250	300
S'1	20.0	18.8	18.3	18.0	17.7
S'2	24.0	22.6	22.0	21.6	21.2
S'3	25.0	23.5	22.9	22.5	22.1
S'4	24.0	22.6	22.0	21.6	21.2
Temp.	350	400	450	500	550
S'1	17.4	17.1	16.7	16.3	15.8
S'2	20.9	20.5	20.1	19.6	19.0
S'3	21.8	21.4	20.9	20.4	19.8
S'4	20.9	20.5	20.1	19.6	19.0
Temp.	600	650	700	750	800
S'1	15.3	14.8	14.3	13.8	11.4
S'2	18.4	17.8	17.2	14.8	12.0
S'3	19.2	18.5	17.9	15.7	12.6
S'4	18.4	17.8	17.2	14.8	12.0
Temp.	850	900	950	1000	-
S'1	8.7	5.9	4.0	2.5	-
S'2	9.3	6.7	4.0	2.5	-
S'3	9.3	6.7	4.0	2.5
S'4	9.3	6.7	4.0	2.5

*Table B-3: maximum allowable stresses S’₁, S’₂, S’₃, S’₄ for ASME SA-266 Grade 1, 2, 3, 4, respectively, ksi; for metal temperatures °F, not exceeding. Table B-3 is corresponding to Table A-3.