A valve datasheet can define pressure class, material, end connection and test standard. It does not, by itself, prove that the factory named in the purchase order can repeatedly manufacture and document the valve as required.
That distinction matters more after the publication of API RP 591, Process Valve Qualification Procedure, Seventh Edition (February 2026). The published description makes one point especially useful for buyers: evaluation under the recommended practice is manufacturing-facility specific. Qualification does not automatically extend to valves made at another facility, even when that facility belongs to the same company or supplies the same brand.
For refinery, petrochemical, LNG, pipeline and other critical process-valve packages, the RFQ should therefore identify both the product requirement and the manufacturing location that will fulfil it.
What “facility specific” changes in an RFQ
Avoid a generic request such as “supplier to comply with API RP 591.” Ask the bidder to connect the offered valve to a traceable manufacturing route:
| RFQ field | What the buyer should request | Why it matters |
|---|---|---|
| Legal manufacturer | Registered company name | Prevents ambiguity between brand owner, trader and factory |
| Manufacturing facility | Full address of the plant performing the relevant work | Qualification is not automatically transferable between sites |
| Valve scope | Type, size range, pressure class, body material and applicable product standard | Evidence for one construction may not represent every offered valve |
| Critical operations | Casting/forging source, machining, assembly, pressure testing and final inspection locations | Reveals outsourced or split production steps |
| Qualification evidence | Report reference, issue date, tested configuration and approving party | Lets the purchaser compare the evidence with the offered scope |
| Change control | Notification requirement for factory, design, material or critical subcontractor changes | Protects the approved supply route after award |
A practical pre-award review sequence
1. Freeze the product standard and service conditions
State the governing product standard and edition, valve type, pressure class, materials, design temperature, fluid, corrosion allowance, end connections, operating mode and required tests. A qualification review cannot correct an incomplete valve specification.
2. Match the offered valve to the qualification envelope
Ask the supplier to provide a simple matrix linking the offered construction to the available qualification evidence. Record any gap instead of treating a similar valve as automatically equivalent.
3. Confirm where work is performed
Identify the locations for design control, incoming-material verification, machining, assembly, pressure testing, nondestructive examination and final release. If private labelling or subcontract manufacture is involved, make the relationship visible before the purchase order is issued.
4. Align the ITP and document package
The inspection and test plan should identify purchaser hold, witness and review points. The final manufacturing record book may need material certificates, heat-treatment records, NDE reports, pressure-test records, dimensional checks, coating records, nameplate details and release documentation, depending on the project.
5. Control post-award changes
Require written approval before changing the named manufacturing facility, qualified construction, material source or critical subcontractor. This prevents commercial substitutions from breaking the technical basis of the award.
Questions to send with the next valve enquiry
- Which exact facility will manufacture, assemble, test and release these valves?
- What valve types, sizes, classes, materials and constructions are covered by the submitted qualification evidence?
- Which operations are subcontracted, and how are those suppliers controlled?
- Does the proposed qualification evidence match the product-standard edition stated in our RFQ?
- What changes would trigger purchaser notification or requalification review?
- Can the supplier provide an ITP and sample manufacturing record book index before award?
Do not confuse three different checks
– Product compliance asks whether the valve meets the governing design and test standard. – Quality-system approval asks whether the organisation operates an accepted management system. – Valve qualification evaluates evidence for a defined valve construction and manufacturing facility.
These checks support one another, but one should not be presented as a substitute for the others.
Build a quote package that can be audited
XHVAL can review project requirements for ball valves, gate valves, globe valves, check valves and butterfly valves. Send the valve list, service conditions, governing standards and required documentation with the RFQ so the technical scope can be checked before price comparison.
For butterfly-valve-specific selection and project support, see XHVAL Butterfly Valve.