A312 TP321 Pipe MAWP Calculator

ASTM A312 TP321 SS Pipe Smls 18Cr-10Ni-Ti, <=3/8" thk.

Pressure Ratings > Pipe MAWP > A312 TP321

Size Variant

Material Properties

Specification

A312 TP321

Description

ASTM A312 TP321 SS Pipe Smls 18Cr-10Ni-Ti, <=3/8" thk.

Tensile Strength

75 ksi

Yield Strength

30 ksi

B16.5 Flange Group

Group 2.4 — Austenitic SS 18Cr-10Ni-Ti

Min Design Temperature

-425 °F

Y Coefficient

Ref 4 — Austenitic steels

Calculator Settings

Corrosion Allowance (in)

Mill Tolerance (%)

Units

Schedule Selection

STDXSXXS10S40S80S2030406080120140160

Temperature Selection

100 °F150 °F200 °F250 °F300 °F350 °F400 °F450 °F500 °F550 °F600 °F650 °F700 °F750 °F800 °F850 °F900 °F950 °F1000 °F1050 °F1100 °F1150 °F1200 °F1250 °F1300 °F1350 °F1400 °F1450 °F1500 °F

Maximum Allowable Working Pressure (psig)

NPS	OD (in)	100 °F	200 °F	300 °F	400 °F	500 °F	600 °F	700 °F	800 °F
1/8	0.405	6,659	6,659	6,659	6,659	6,426	6,093	5,827	5,627
1/4	0.54	6,438	6,438	6,438	6,438	6,213	5,891	5,633	5,440
3/8	0.675	5,210	5,210	5,210	5,210	5,028	4,767	4,559	4,403
1/2	0.84	4,995	4,995	4,995	4,995	4,821	4,571	4,371	4,221
3/4	1.05	4,074	4,074	4,074	4,074	3,931	3,727	3,564	3,442
1	1.315	3,810	3,810	3,810	3,810	3,676	3,486	3,333	3,219
1 1/4	1.66	3,137	3,137	3,137	3,137	3,027	2,870	2,745	2,651
1 1/2	1.9	2,822	2,822	2,822	2,822	2,723	2,582	2,469	2,384
2	2.375	2,377	2,377	2,377	2,377	2,294	2,175	2,080	2,009
2 1/2	2.875	2,600	2,600	2,600	2,600	2,509	2,379	2,275	2,197
3	3.5	2,258	2,258	2,258	2,258	2,179	2,066	1,975	1,908
3.5	4	2,059	2,059	2,059	2,059	1,987	1,884	1,802	1,740
4	4.5	1,914	1,914	1,914	1,914	1,847	1,751	1,675	1,617
5	5.563	1,678	1,678	1,678	1,678	1,619	1,535	1,468	1,418
6	6.625	1,524	1,524	1,524	1,524	1,471	1,395	1,334	1,288
7	7.625	1,421	1,421	1,421	1,421	1,371	1,300	1,243	1,201
8	8.625	1,342	1,342	1,342	1,342	1,295	1,228	1,174	1,134
9	9.625	1,275	1,275	1,275	1,275	1,231	1,167	1,116	1,078
10	10.75	1,217	1,217	1,217	1,217	1,175	1,114	1,065	1,029
12	12.75	1,051	1,051	1,051	1,051	1,014	962	920	888
14	14	955	955	955	955	922	874	836	807
16	16	834	834	834	834	805	763	730	705
18	18	740	740	740	740	714	677	647	625
20	20	665	665	665	665	642	608	582	562
22	22	604	604	604	604	583	552	528	510
24	24	553	553	553	553	534	506	484	467
26	26	510	510	510	510	492	467	446	431
28	28	473	473	473	473	457	433	414	400
30	30	441	441	441	441	426	404	386	373
36	36	367	367	367	367	354	336	321	310
42	42	314	314	314	314	303	288	275	266
44	44	300	300	300	300	290	275	263	254
46	46	287	287	287	287	277	263	251	242
48	48	275	275	275	275	265	252	241	232

Custom Wall Thickness

NPS

Wall Thickness (in)

Allowable Stress vs Temperature

Matching Flange Group

Group 2.4 — Austenitic SS 18Cr-10Ni-Ti(A182 F321/F321H, A240-321/321H)

Disclaimer: This calculator is for guidance only. Results are based on ASME B31.3-2024 allowable stresses for seamless pipe (Ej=1.0, W=1.0). Always verify against the current edition of the standard. The engineer of record is responsible for all design decisions.