Castings occupy a unique position in the materials supply chain. Unlike rolled plate or drawn bar, a casting is not cut from a common stock — it is an individual, near-net-shape production item, typically poured from a specific heat and heat-treated as a specific lot. Every casting in an order has a direct traceability path back to a single pour event, and the certificate that documents that pour event is the casting MTC.
The complexity of casting certification arises from this individuality. A 200mm gate valve body is not fungible with another 200mm valve body from a different heat. The chemistry, the casting method (sand cast, investment cast, centrifugal cast), the heat treatment, the NDE results, and the pressure test data are all specific to that individual casting or casting lot. When any of these elements are missing, undocumented, or outside specification, the casting cannot be accepted for pressure service under ASME B16.34, EN 12516, or API 6D — regardless of whether it looks fine visually.
Understanding what must appear on a casting MTC, and what the most frequent rejection triggers are, is essential for any quality team that sources castings for pressure-containing applications.
Governing Standards for Casting Certification
ASTM A703 / A703M — Steel Castings for Pressure-Containing Parts
ASTM A703 is the general requirements standard for steel castings in the same way A788 governs forgings. It applies to all ASTM steel casting specifications for pressure-containing parts, including the widely used A216 (carbon steel), A217 (alloy steel and martensitic stainless), A351 (austenitic stainless), A352 (low-temperature service), and A995 (duplex stainless) grades.
ASTM A703 mandates that the MTC include: heat analysis; mechanical test results with coupon identification; hardness test results; heat treatment condition and temperature; NDE results per specified method and acceptance criteria; pressure test results if required; and marking identification that correlates the casting to the certificate. The standard also requires that test coupons be cast from the same heat as the castings they represent, and processed (heat-treated) with the production castings — a test coupon heat-treated separately is not valid under A703.
EN 1559 — Founding: Technical Conditions of Delivery
EN 1559 is the European framework standard for the technical conditions of delivery for castings. Part 1 covers general requirements; Part 2 covers steel castings specifically. EN 1559 works in conjunction with EN 10204 for certificate type specification. The EN 1559 equivalent of A703 defines what the MTC must contain, while EN 10204 defines who must issue and countersign it.
ASME B16.34 — Valves: Flanged, Threaded, and Welding End
ASME B16.34 is the primary standard for industrial valves used in pressure service. It specifies pressure-temperature ratings for valve bodies made from specific material grades, and it requires that valve body castings be produced in accordance with specific ASTM casting specifications (SA-216, SA-217, SA-351, etc. under ASME Section II equivalents). B16.34 does not specify its own MTC format but requires that all castings be from listed materials with valid certification.
For ASME Code valves, the casting MTC must satisfy both the applicable ASTM standard (SA-216 for carbon steel, for example) and EN 10204 requirements for certificate type.
Field-by-Field Casting MTC Requirements
| Field | Governing Standard | Required Content |
|---|---|---|
| Heat number | A703 | Unique identifier for each heat; must match marking on casting |
| Casting identification number | A703 / customer requirement | Unique casting or lot identifier; must match marking |
| Grade and specification | A703 | Exact ASTM/ASME grade designation and specification edition |
| Casting process | Customer / EN 1559 | Sand, investment, centrifugal, etc. — affects NDE method choice |
| Heat analysis | A703 mandatory | All required elements within specification limits |
| Product analysis | A703 / per order | If specified; taken from the casting body, not the coupon |
| Yield strength | A703 | At or above minimum for specified grade |
| Tensile strength | A703 | At or above minimum for specified grade |
| Elongation | A703 with gage length | At or above minimum; gage length documented |
| Reduction of area | A703 | At or above minimum if required by grade |
| Charpy impact energy and temperature | A703 / A352 / order requirement | Both values; temperature matches low-temp service requirement |
| Hardness | A703 / NACE where applicable | Within specified range (HB for most, HRC for sour service) |
| Heat treatment condition | A703 mandatory | Condition code and treatment temperature documented |
| Test coupon identification | A703 | Coupon must be from same heat and heat-treated with production casting |
| NDE method and results | A703 / A903 / EN 12680 | Method, coverage, acceptance criteria, technician qualification |
| Pressure test results | ASME B16.34 / API 6D | Hydrostatic test pressure, duration, and acceptance result |
| Weld repair documentation | A703 | If casting was repaired by welding: procedure, extent, PWHT, re-examination |
| EN 10204 type | Customer PO | 3.1 or 3.2 as specified; correct signatures |
| Marking correlation | A703 | Certificate fields must correlate to physical marking on casting |
The Weld Repair Issue
This is the casting certification element that catches the most buyers by surprise. Foundries regularly repair casting discontinuities by welding — it is an accepted and standard practice. ASTM A703, EN 1559, and most specification bodies permit weld repair of castings under defined conditions. But the repair must be documented.
If a casting was weld-repaired, the MTC (or a supplementary weld repair record that is formally attached to the MTC) must document: the defect type and location before repair, the welding procedure used (WPS reference), the welder qualification, the post-weld heat treatment (PWHT) if performed, and the NDE re-examination results after repair.
A casting MTC that shows clean NDE results but omits the fact that the casting was weld-repaired before those results were obtained is missing required documentation — and in some cases, constitutes fraud. Quality teams receiving castings that show surface grinding or irregular surface texture inconsistent with the casting process should treat this as a trigger for asking the foundry to confirm whether weld repair was performed.
For castings in NACE MR0175 sour service, weld repairs create additional hardness concerns: the weld HAZ may exceed the 22 HRC limit even when the base casting is compliant, and post-weld hardness testing and documentation are mandatory.
EN 10204 Types for Castings: Common Misapplication
The most common EN 10204 misapplication in casting supply chains is accepting a Type 2.2 (non-specific test report) for pressure service castings. A Type 2.2 certificate does not provide traceability to the specific heat — the test results may apply to a batch, a campaign, or a product family, not to the individual castings in the shipment. For ASME Code pressure-containing castings, ASME Section II and B16.34 require traceability to the specific heat — which means EN 10204 Type 3.1 is the minimum.
The second common misapplication: accepting a document labeled "3.1" that is signed only by a sales representative or a shipping department employee, not by the manufacturer's authorized QA representative who is organizationally independent of production. Under EN 10204, the 3.1 signatory must be the manufacturer's "authorised representative of the inspection department." A shipping manager's signature is not compliant, regardless of what the signature line says.
Subsea valve bodies, nuclear castings, and critical rotating equipment in oil and gas typically require EN 10204 3.2 with third-party co-signature. This must be specified on the purchase order before the casting is poured — it is not possible to obtain retrospective third-party co-signature after pouring and heat treatment are complete without arranging witnessed retesting.
NDE for Castings: What Must Be Documented
Castings for pressure service require NDE that is fundamentally different from rolled product inspection because of the internal discontinuities unique to the casting process: porosity, shrinkage cavities, hot tears, cold shuts, and oxide inclusions.
Radiographic Testing (RT): The most common method for critical casting zones (flanged ends, pressure-containing walls). ASTM E446 (steel castings ≤ 114mm thick) or ASTM E186 / E280 (thicker sections) specify the reference radiographs against which acceptance is evaluated. For ASME B16.34 castings, the applicable acceptance level (1 through 6 for each defect type) must be documented.
Ultrasonic Testing (UT): ASTM A609 for steel castings; EN 12680-2 for steel castings in European markets. UT is required for thick-walled castings where RT cannot provide adequate penetration.
Magnetic Particle Testing (MT): ASTM E709 for surface and near-surface discontinuities in ferromagnetic castings. Required for the pressure-containing areas of most valve bodies in carbon and alloy steel.
Liquid Penetrant Testing (PT): For non-magnetic materials (austenitic stainless, nickel alloys) and as a complement to MT for surface-breaking discontinuities.
What must appear on the MTC or referenced NDE report:
- The NDE method and the governing standard
- The examination coverage (100% of pressure-containing areas, or specific zones per reference drawing)
- The acceptance criteria (RT acceptance level, UT rejection criteria, MT/PT indication size limit)
- The NDE technician's name and qualification level (Level II or III per EN ISO 9712 or ASNT SNT-TC-1A)
- Examination date
- Accept or reject disposition for each examined zone
An MTC that states "RT: Passed" without the standard, acceptance criteria, technician qualification, or examination extent is not compliant — it is a non-documented claim.
Pressure Testing Castings for ASME B16.34 Compliance
ASME B16.34 requires hydrostatic shell testing of every valve at 1.5 times the maximum allowable working pressure (MAWP) for the rated class and material group. The casting MTC or a supplementary pressure test certificate must document: the test pressure, the test duration, the test medium (typically water), and the result (no leakage, no permanent deformation).
For API 6D (Pipeline Valves), shell hydrostatic testing requirements are similar, and the test certificates are often required as part of the vendor data package submission to the project.
Missing pressure test data is a direct hold: a valve body casting cannot be used in ASME B16.34 or API 6D service without documented hydrostatic pressure test results.
How TestCert Handles Casting Certification
Casting MTCs are more complex per-document than standard rolled product certificates. They include NDE method references, heat treatment condition codes, weld repair disclosures, pressure test results, and test coupon identification that do not appear on most pipe or plate MTCs. The format varies dramatically between foundries — some use structured digital documents, others use hand-typed forms with fields unique to their quality management system.
TestCert extracts all casting-specific fields alongside standard chemistry and mechanical property data. NDE references, heat treatment conditions, weld repair disclosures, and pressure test results are captured in structured form alongside the core chemistry and mechanical values. Validation rules are configured for the applicable casting standard (ASTM A216, A217, A351, etc.) and the customer's EN 10204 type requirement. An A351 Gr. CF8M austenitic stainless casting for ASME B16.34 Class 900 service has different validation requirements from a carbon steel A216 Gr. WCB casting for general utility service — the system applies the correct ruleset automatically.
When an NDE reference is present but incomplete, when weld repair is flagged but no repair record is attached, or when the EN 10204 type does not match the PO requirement, the exception is raised at receiving before the casting enters any inspection or assembly process. The complete casting documentation package — MTC, NDE report, pressure test certificate, weld repair record — is stored as a linked set, retrievable in seconds when the ASME Authorized Inspector asks for it.
See how TestCert handles casting certification at testcert.io — book a demo or start a trial.