ASTM Piping Materials Compatibility Table

Quick Reference

This guide provides ASTM material matching tables for piping systems. Scroll to the main compatibility table to find which fittings, flanges, valves, and stud bolts match your pipe material grade.

Piping Materials Compatibility

Why Materials for Piping Products Should Match?

When you specify an A106 Gr. B pipe, the fittings, flanges, and valves in that line need compatible grades. Mixing incompatible materials creates problems:

piping isometrics

Issue	Why It Matters
Galvanic corrosion	Dissimilar metals in contact with an electrolyte accelerate corrosion at the junction
Thermal stress	Different expansion coefficients cause joint stress during temperature swings
Weld defects	Mismatched compositions lead to porosity, cracking, or incomplete fusion
Mechanical mismatch	Different yield strengths create weak points under pressure or load
Inconsistent corrosion resistance	The weakest link determines system life

The pipe class specification should define compatible materials for all components. The matching tables below serve as a quick reference when reviewing or creating specs.

Pro Tip

When reviewing mill test certificates (MTCs), don’t just check the ASTM designation - verify the actual chemical composition and mechanical properties meet spec requirements. A certificate stating “A234 WPB” means nothing if the carbon content exceeds the allowable limit. Cross-reference the values against the ASTM standard.

Piping Materials by Fluid Type

Material selection depends primarily on the fluid service. Below is a quick-reference guide organized by fluid category.

Water Systems

Service	Common Materials
Potable water	ASTM A53 (with coating), Ductile Iron, PVC/HDPE
Wastewater	ASTM A536 (ductile iron), HDPE ASTM D3035
Chlorinated water	PVC ASTM D1785, CPVC ASTM F441 (higher temp)
Seawater	Cu-Ni 90/10 or 70/30, Titanium Gr. 2/5

Oil & Gas

Service	Common Materials
Crude oil / hydrocarbons	API 5L Gr. B-X80, ASTM A106 Gr. B
Natural gas	API 5L Gr. B-X80, ASTM A333 Gr. 6 (low temp)
Thermal oil	Alloy Steel P22, SS 321
Molten sulfur	Inconel 625, Alloy 20

Steam & High Temperature

Service	Common Materials
Medium pressure steam	ASTM A106 Gr. B/C
High pressure steam	ASTM A335 P11, P22, P91
Superheated steam	Alloy Steel T91, SS 347H

Cryogenic Services

Service	Common Materials
LNG / Liquid N2	SS 304/316 A312, ASTM A333 Gr. 6
Liquid helium	SS 316L
Liquid argon	Aluminum 6061

Corrosive Chemicals

Fluid	Recommended Materials
Hydrochloric acid	PTFE-lined, Hastelloy C276
Sulfuric acid	Alloy 20, Duplex 2205
Nitric acid	SS 316L, Hastelloy B3
Caustic soda (NaOH)	Nickel 200, Hastelloy C2000
Chlorine gas	Hastelloy C276, Titanium
Ammonia	Carbon steel, SS 316

Special Services

Service	Common Materials
Slurries/abrasives	Rubber-lined CS, HDPE
Brine solutions	Super Duplex, Titanium
Glycol mixtures	Cu-Ni alloys, SS 316L
Oxygen (cleaned)	Deoxidized copper, SS 304/316 (cleaned)

Piping Materials Match Table (ASTM Grades)

This is the core reference table. Given a pipe material, read across to find compatible grades for fittings, forgings, valves, and bolting.

Example: For an A106 Gr. B pipe, use ASTM A234 WPB fittings, A105 flanges and forged fittings, A216 WCB cast valves, and A193 B7/A194 2H stud bolts.

PIPING MATERIALS	PIPES	BW FITTINGS	FORGINGS*	CAST VALVES	STUD BOLTS
High-Temperature Carbon Steel	A106 Gr A	A234 Gr WPA	A105	A216 Gr WCB	A193 Gr B7A194 Gr 2H
A106 Gr B/A53 Gr B/API 5L Gr. B	A234 Gr WPB	A105	A216 Gr WCB
A106 Gr C	A234 Gr WPC	A105	A216 Gr WCB
Carbon Steel Alloy High-Temp	A335 Gr P1	A234 Gr WP1	A182 Gr F1	A217 Gr WC1	A193 Gr B7A194 Gr 2H
A335 Gr P11	A234 Gr WP11	A182 Gr F11	A217 Gr WC6
A335 Gr P12	A234 Gr WP12	A182 Gr F12	A217 Gr WC6
A335 Gr P22	A234 Gr WP22	A182 Gr F22	A217 Gr WC9
A335 Gr P5	A234 Gr WP5	A182 Gr F5	A217 Gr C5
A335 Gr P9	A234 Gr WP9	A182 Gr F9	A217 Gr C12
A 335 Gr P91	A234 Gr WP91	A182 Fr F91
Carbon Steel Alloy Low-Temp	A333 Gr 6	A420 Gr WPL6	A350 Gr LF2	A352 Gr LCB	A320 Gr L7A194 Gr 7
A333 Gr 3	A420 Gr WPL3	A350 Gr LF3	A352 Gr LC3
Austenitic Stainless Steel	A312 Gr TP304	A403 Gr WP304	A182 Gr F304	A182 Gr F304	A193 Gr B8A194 Gr 8
A312 Gr TP316	A403 Gr WP316	A182 Gr F316	A182 Gr F316
A312 Gr TP321	A403 Gr WP321	A182 Gr F321	A182 Gr F321
A312 Gr TP347	A403 Gr WP347	A182 Gr F347	A182 Gr F347

• Forgings include: forged fittings, flanges, forged valves, some types of gaskets

Common Mistake

Substituting materials without checking weldability compatibility. F316L fittings welded to 316H pipe may seem fine since both are “316 stainless,” but the carbon content difference affects welding procedures and service limitations. Always verify that substituted materials have compatible compositions for the intended weld procedure.

Key ASTM Materials for Piping

Steel Pipes

Steel pipes

Category	Key Specs	Typical Application
Carbon Steel	A53, A106, A333	General service, high temp, low temp
Alloy Steel	A335, A691	High temp/pressure (chrome-moly)
Stainless	A312, A358	Corrosive service, high temp
Duplex	A790, A928	High strength + corrosion resistance

For detailed coverage of each material type:

• Carbon steel pipes (A53, A106, A333)
• Alloy steel pipes (A335 P-grades)
• Stainless and duplex pipes (A312, A790)

Cast Valves

Cast Ball Valve

Category	Spec	Common Grades
Carbon steel	A216	WCA, WCB, WCC
Low-temp carbon	A352	LCB, LCC
Stainless	A351	CF8, CF8M, CF3M
Alloy	A217	WC6, WC9, C5, C12
Duplex	A995	4A (CD3MN)
Ni-Cu alloy	A494	CW6M

See ASTM valve materials for complete specifications.

Forged Products (Valves, Flanges, Fittings)

Forged components share common ASTM specs across valves, flanges, and fittings:

forged valves

Material	Spec	Typical Grades	Application
Carbon steel	A105	-	Standard temp service
Low-temp carbon	A350	LF2, LF3	Low temp w/ impact testing
Alloy steel	A182	F5, F9, F11, F22, F91	High temp chrome-moly
Stainless	A182	F304, F316, F321, F347	Corrosive service

wn flange

For detailed specifications:

• Forged flanges (A105, A182, A350)
• Forged fittings ASME B16.11
• Forged valve materials

Buttweld Fittings

buttweld fittings

Material	Spec	Key Grades
Carbon steel	A234	WPB, WPC
Alloy steel	A234	WP1, WP5, WP9, WP11, WP22, WP91
Stainless	A403	WP304(L), WP316(L), WP321, WP347
Duplex	A815	S31803, S32205, S32750
High yield	A860	WPHY 42, 52, 60, 65, 70

See buttweld fitting materials ASME B16.9 for complete specifications.

Stud Bolts

stud bolts

Service	Stud Spec	Nut Spec	Common Grades
High temp/pressure	A193	A194	B7/2H (standard), B16/4 (higher temp)
Low temperature	A320	A194	L7/4, L43/4
Corrosive service	A193	A194	B8/8 (304), B8M/8M (316)
General purpose	A307	-	Grade B

The B7/2H combination covers most standard applications. For service above 450°C (840°F), consider B16. For cryogenic service, specify A320 L7 with impact testing.

See stud bolts for flanges for sizing and torque information.

Carbon Content & Weldability

Why Carbon Content Matters

Carbon makes steel stronger but harder to weld. More carbon means more risk of brittle microstructures (martensite) forming in the heat-affected zone (HAZ), which leads to cracking.

Carbon Level	% Carbon	Weldability	Notes
Low (mild steel)	< 0.3%	Excellent	Standard welding procedures
Medium	0.3-0.6%	Moderate	May need preheat and PWHT
High	> 0.6%	Difficult	Special procedures required

Most piping materials fall in the low-carbon range. A106 Gr. B, for instance, has a max carbon content of 0.30%, making it readily weldable.

Carbon Equivalent (CE)

Carbon equivalent accounts for other alloying elements (Mn, Cr, Mo, V) that also affect hardenability. Lower CE = better weldability. The welding procedure qualification considers CE when determining preheat and PWHT requirements.

Improving Weldability

For materials with higher carbon or CE values:

• Preheat - Slows cooling rate, reduces martensite formation
• PWHT - Relieves stress, tempers hard microstructures
• Low-hydrogen processes - Reduces hydrogen-induced cracking risk

Fully Killed vs. Semi-Killed Carbon Steel

Practical Note

For piping applications, this distinction rarely matters-virtually all pressure piping uses fully killed steel. Semi-killed steel is limited to non-critical structural applications where cost outweighs quality requirements.

Property	Fully Killed	Semi-Killed
Deoxidation	Complete (Si, Al added)	Partial
Grain structure	Fine	Coarse
Porosity	None	Some
Uniformity	High	Moderate
Cost	Higher	Lower

Fully killed steel undergoes complete deoxidation before casting, producing fine grain structure and uniform properties. This is mandatory for pressure piping, forgings, and low-temperature service where impact toughness matters.

Semi-killed steel retains some oxygen, resulting in coarser grains and minor porosity. Acceptable for general structural applications but not for pressure-containing piping.

Field Note

Maintain material traceability during fabrication - mark heat numbers on cut pieces before removing the original stencil. Many projects require positive material identification (PMI) at receiving and after installation. Without traceable markings, you’ll be doing PMI testing on hundreds of components just to prove material compliance.