Valve Procurement: Key Clauses in Purchase Orders

The Importance of a Complete Purchase Order

A valve purchase order (PO) is the contract that defines exactly what the buyer receives. Vague or incomplete POs result in valves that do not meet service requirements, delayed deliveries, and costly disputes at receiving inspection.

Essential Technical Clauses

• Design standard and pressure class (e.g., API 6D, Class 900)

• Body, trim, and seat materials with grade and heat number requirements

• End connections and facing type (RF, RTJ, BW schedule)

• Testing requirements per API 598, API 6D, or project-specific ITP

• Marking per MSS SP-25 or API 6D marking requirements

• Applicable special requirements: NACE, low-temperature, fire-safe, fugitive emission

Commercial and Logistics Clauses

• Delivery lead time and milestone schedule

• Packing and preservation requirements for long-term storage

• Documentation requirements: MTRs, hydro test reports, NDE reports, COC

• Spare parts list for commissioning and two-year operational spares

Inspection and Witness Points

Specify hold and witness points in the PO or reference the project ITP. Without explicit hold-point language, the manufacturer may complete testing before notifying the client inspector—resulting in re-test costs and schedule impact.

Vendor Data Requirements

Require the manufacturer to submit datasheets, drawings, and test procedures for approval before fabrication starts. Approval of submittals before production prevents rework when design details do not meet project requirements.