| 1 | Application fit | Whether the supplier offers air-release, air/vacuum, and combination valves suited to the pipeline duty. | Share the fluid, operating conditions, pipeline profile, and valve function; request a written selection rationale. |
| 2 | Applicable standards | Whether the proposed valve is designed and documented to the specification required for the project and market. | For waterworks applications, ask whether the product is covered by AWWA C512 or EN 1074-4, as applicable. Confirm the exact edition and scope. |
| 3 | Pressure and temperature limits | Rated pressure, operating temperature range, and any limits related to the selected materials or configuration. | Check the datasheet against the project design conditions; do not treat a nominal size or pressure class as a complete operating limit. |
| 4 | Air-flow and sizing data | Sizing guidance and performance data appropriate to air admission and air discharge requirements. | Request the sizing method, relevant flow curves or tables, and assumptions used. Have the selection checked against the pipeline design. |
| 5 | Materials and compatibility | Body, trim, float, elastomer, and coating materials compatible with the fluid and service environment. | Request a material list and confirm compatibility, corrosion exposure, potable-water requirements, and any project-specific material restrictions. |
| 6 | Testing and traceability | Defined inspection and test records, product identification, and traceability appropriate to the purchase specification. | Ask for sample test documentation and clarify whether inspection is performed on each unit, by batch, or by another stated method. |
| 7 | Quality management | The supplier’s quality controls and the scope and validity of any management-system certification it claims. | Verify certificate status and scope with the issuing or accreditation body. ISO 9001 certification concerns a quality management system; it is not, by itself, product approval. |
| 8 | Export and documentation readiness | Ability to supply the documents and markings required for the destination country and project. | Confirm document language, applicable conformity requirements, country-of-origin paperwork, shipping terms, and packing details before ordering. |
| 9 | Delivery and spare-parts support | Quoted lead time, availability of replacement parts, and the process for handling technical questions or claims. | Request a dated delivery commitment, recommended spare-parts list, warranty terms, and a named point of contact. |
| 10 | Total cost and commercial clarity | Comparable scope of supply, pricing assumptions, payment terms, freight, and any exclusions. | Compare like-for-like quotations, including accessories, inspection documents, packaging, delivery terms, and after-sales support. |