ASTM A312 vs ASTM A213 Difference between ASME SA213 and ASME SA312

The primary differences between ASTM A312 and ASTM A213 standards lie in their scope, application, and material specifications. Here’s a concise comparison in English:

1. Scope & Application

ASTM A312 / ASME SA312:
Covers seamless and welded austenitic stainless steel pipes (e.g., grades TP304, TP316) intended for high-temperature and general corrosive service. Commonly used in chemical, petrochemical, power generation, and food processing industries for piping systems.
ASTM A213 / ASME SA213:
Specifies seamless ferritic and austenitic alloy-steel tubes (e.g., T11, T22, TP347) designed for boilers, superheaters, and heat exchangers in high-temperature/pressure environments (e.g., power plants, refineries).

2. Manufacturing Process

ASTM A312: Permits both seamless (S) and welded (W) pipes, with welded pipes requiring additional testing (e.g., hydrostatic or nondestructive examination).
ASTM A213: Exclusively for seamless tubes, ensuring uniformity for critical high-pressure applications.

3. Material Grades

ASTM A312: Focuses on stainless steel (300-series and similar alloys).
ASTM A213: Includes low-alloy steels (e.g., chromium-molybdenum grades like T9, T91) and some stainless steels, such as ASME SA213 TP304L and ASME SA213 TP316L optimized for creep resistance and thermal stability.

4. Dimensions & Sizes

ASTM A312: Typically covers larger diameters (NPS 1/8 to 24) for piping systems.
ASTM A213: Governs smaller-diameter tubes (often ≤ NPS 5) for heat-transfer equipment.

5. Testing Requirements

ASTM A312: Mandates hydrostatic or nondestructive testing for welded pipes; optional for seamless. And ASTM A312 don’t have requirements of Hardness Testing.
ASTM A213: Requires stricter nondestructive testing (e.g., eddy current) for all tubes, ensuring defect-free performance in critical applications.

Key Takeaway

ASTM A312 is broader, addressing stainless steel pipes for both corrosive and high-temperature piping. ASTM A213 is specialized for seamless alloy-steel tubes in extreme thermal conditions (e.g., boilers). The choice depends on application demands: corrosion resistance vs. high-temperature strength.

Differences of ASTM A213 And ASTM A312

Standard	ASTM A213	ASTM A312
Basic Difference	Seamless Steel Tubing	Welded and Seamless Steel Pipe
Wall Thickness	Mostly minimum wall thickness (0, +20%), also accept average wall thickness (+/-10%)	Average Wall Thickness
Hardness	192HBW OR 90HRB Maximum	Do not require
Nickel of 316H	11.0 – 14.0%	10.0 – 14.0%
Applications	Heat exchangers and Superheaters to maintain the transmission temperature of the different substances.	Stainless steel pipe for high-temperature and general corrosive service.

Standard Item	ASTM A213	ASTM A269	ASTM A312
Grade	304 304L 304H 304N 304LN 316 316L 316Ti 316N 316LN 321 321H 310S 310H 309S 317 317L 347 347H	304 304L 304H 304N 304LN 316 316L 316Ti 316N 316LN 321 321H 310S 310H 309S 317 317L 347 347H	304 304L 304H 304N 304LN 316 316L 316Ti 316N 316LN 321 321H 310S 310H 309S 317 317L 347 347H
Yield Strength (Mpa)	≥170；≥205	≥170；≥205	≥170；≥205
Tensile Strength (Mpa)	≥485；≥515	≥485；≥515	≥485；≥515
Elongation(%)	≥35	≥35	≥35
Hardness (Mpa)	192HBW OR 90HRB Maximum	192HBW OR 90HRB Maximum	Do not required
Hydrostatic Test	OD(mm) Pressure max (MPa)	OD(mm) Pressure max (MPa)	OD(mm) Pressure max (MPa)
	D<25.4, 7Mpa	D<25.4, 7Mpa	D≤88.9, 17MPa
	25.4≤D<38.1, 10Mpa	25.4≤D<38.1, 10Mpa
	38.1≤D<50.8, 14Mpa	38.1≤D<50.8, 14Mpa
	50.8≤D<76.2， 17MPa	50.8≤D<76.2， 17MPa	D>88.9, 19MPa
	76.2≤D<127， 24MPa	76.2≤D<127， 24MPa
	D≥127, 31Mpa	D≥127, 31Mpa
	P=220.6t/D	P=220.6t/D	P=2St/D S=50%Rp0.2
Intergranular Corrosion Test	ASTM A262 E	ASTM A262 E	ASTM A262 E
Eddy Current Test	ASTM E426	ASTM E426	ASTM E426
O.D. Tolerance (mm)	O.D. and Tolerance	O.D. and Tolerance	O.D. and Tolerance
	D<25.4 +/-0.10	D<38.1 +/-0.13	10.3≤D≤48.3 +0.40/-0.80
	25.4≤D≤38.1 +/-0.15
	38.1<D<50.8 +/-0.20	38.1≤D<88.9 +/-0.25	48.3<D≤114.3 +0.80/-0.80
	50.8≤D<63.5 +/-0.25
	63.5≤D<76.2 +/-0.30	88.9≤D<139.7 +/-0.38	114.3<D≤219.1 +1.60/-0.80
	76.2≤D≤101.6 +/-0.38
	101.6<D≤190.5 +0.38/-0.64	139.7≤D<203.2 +/-0.76	219.1<D≤457.0 +2.40/-0.80
	190.5<D≤228.6 +0.38/-1.14
W.T. Tolerance (mm)	O.D. W.T. Tolerance	O.D. W.T. Tolerance	O.D. W.T. Tolerance
	D≤38.1 WT +20%/-0	D<12.7 WT +/-15%	10.3≤D≤73.0 WT +20.0%/-12.5%
	D>38.1 WT +22%/-0	12.7≤D<38.1 WT +/-10%	88.9≤D≤457.0 t/D ≤5% WT +22.5%/-12.5%
		D≥38.1 WT: +/-10%	88.9≤D≤457.0 t/D >5% WT +15.0%/-12.5%