ASTM A216

USED FOR:

ASTM A216 governs carbon steel castings for valves, flanges, fittings, and other pressure-containing parts

intended for high-temperature service. The castings are suitable for fusion welding where welding is required.

This is a casting specification covering carbon steel castings for valves, flanges, fittings, and other pressure-containing components. It does not cover pipe, forgings, plate, or wrought fittings. If the component is machined from a forging or fabricated from plate, ASTM A216 is the wrong specification.

RELATED STANDARDS:

Sibling specs: ASTM A352 covers the low-temperature counterpart castings (LCB, LCC, LC1–LC4, CA6NM, etc.) where impact toughness at sub-ambient temperatures is required; ASTM A217 covers alloy steel castings (WC1, WC6, WC9, C5, C12, C12A) for elevated-temperature and creep-range service; ASTM A351 covers austenitic stainless steel castings (CF8, CF8M, CF3M, etc.) for corrosive or cryogenic duty. A216 is the plain carbon steel member of this family for moderate and elevated-temperature service.

Design code that invokes it: ASME B16.34 lists ASTM A216 grades as acceptable valve body materials with associated pressure-temperature ratings. ASME B16.5 lists ASTM A216 materials for flanges and flanged fittings where applicable, while ASME B31.3 and ASME B31.1 use the allowable stresses published in ASME Section II Part D (SA-216) for pressure design.

Dimensional standards that pair with it: ASTM A216 defines material requirements only. End-to-end and face-to-face dimensions of cast valves are defined by ASME B16.10, flange dimensions and ratings by ASME B16.5 and ASME B16.34, while butt-weld end preparations are covered by ASME B16.25.

GRADE / TYPE RANGE:

ASTM A216 includes three grades: WCA, WCB, and WCC. All are carbon or carbon-manganese steel castings. Moving from WCA to WCC generally provides higher tensile and yield strength, achieved primarily through manganese content rather than increased carbon.

WCC has the lowest maximum carbon content and the highest permitted manganese content of the three grades, providing an excellent balance between strength and weldability.

WCA is the lowest-strength grade and is relatively uncommon. The specification also limits residual alloying elements such as copper, nickel, chromium, molybdenum, and vanadium, including combined residual limits and carbon/manganese relationships, so heat chemistry should always be verified.

In practice, grade selection affects the mechanical properties and the allowable stresses assigned by the applicable ASME code. WCB and WCC generally provide higher strength than WCA, while pressure class ratings remain those established by the applicable ASME standard for the selected material.

WCB is the standard choice for most carbon steel valve bodies, while WCC may be selected where improved weldability or additional strength margin is desired.

DESCRIPTION:

ASTM A216 covers carbon steel castings for valves, flanges, fittings, and other pressure-containing components produced by conventional foundry practice for elevated-temperature service.

Castings shall be supplied in the heat-treated condition required by ASTM A216. The permitted heat treatment (such as annealing, normalizing, or normalizing and tempering) depends on the grade and the manufacturer’s processing route.

The specification requires tensile testing and chemical analysis in accordance with the lot and sampling requirements defined by ASTM A216. Additional non-destructive examinations such as radiography (RT), ultrasonic testing (UT), magnetic particle testing (MT), or liquid penetrant testing (PT) are not mandatory unless specified by supplementary requirements or by the purchase order.

Weld repair of casting defects is permitted under controlled conditions using qualified welding procedures. Major repairs may require post-weld heat treatment and purchaser approval, depending on the specification and purchase requirements.

Marking includes the manufacturer’s identification, grade designation, and heat identification to ensure full traceability throughout the component’s service life.

TYPICAL INDUSTRY USE:

ASTM A216 is the workhorse specification for carbon steel cast valve bodies, pump casings, and other pressure-containing cast components used throughout the oil & gas, refining, petrochemical, power generation, and general process industries.

In conventional carbon steel piping systems based on ASTM A106 pipe and ASTM A105 forgings, ASTM A216 WCB is by far the most common casting material for valves.

IMPORTANT NOTES:

• Confusion with related specifications is common. The most frequent mistake is specifying WCB where the design minimum temperature actually requires impact-tested castings. For low-temperature service, ASTM A352 grades such as LCB or LCC are generally the appropriate choice rather than attempting to qualify WCB. Likewise, WCB (casting) should never be confused with ASTM A234 WPB (wrought butt-welding fittings).

• Some foundries produce castings whose chemistry and mechanical properties satisfy more than one specification or grade, but dual certification should never be assumed. It must always be demonstrated through full compliance with the applicable specification and supported by certified test results.

• For sour service, ASTM A216 WCB and WCC may be suitable when all requirements of NACE MR0175 / ISO 15156 are satisfied, including hardness limitations and any required heat treatment. Where weld repairs are performed, repair procedures, post-weld heat treatment, hardness verification, and repair records should be carefully controlled and documented.

• From a procurement perspective, casting quality can vary significantly between foundries despite identical ASTM designations. For critical services, foundry qualification, control of major weld repairs, and Positive Material Identification (PMI) are recommended to verify chemistry and maintain material integrity. Field welding requirements should also be reviewed against the casting’s heat treatment condition.