| Valve Design and Application | Valve type, nominal size, pressure class, temperature range, media, and connection standard | The product specification must state applicable design and connection standards. ASME B16.34 covers many industrial valves; EN 13828 applies to manually operated copper-alloy ball valves for water services. | Approved drawings, product data sheet, dimensional drawing, pressure-temperature rating, and connection details | Reject suppliers that provide only a general catalog without application-specific ratings. |
| Body and Component Materials | Valve body, ball, stem, seat, seals, handle, and fasteners | Material grades must be declared and suitable for the intended pressure, temperature, and fluid. Copper-alloy components may be specified using applicable EN or ASTM material designations. | Material certificates, incoming inspection records, alloy verification reports, and bill of materials | Prefer suppliers with heat/batch traceability from raw material receipt through final shipment. |
| Chrome Plating Quality | Surface preparation, base coating, chrome layer, adhesion, corrosion resistance, and appearance | Chrome-plating thickness and corrosion requirements should be defined in the purchase specification because requirements vary by application. ISO 1456 provides requirements for electrodeposited nickel plus chromium coatings. | Plating process specification, coating-thickness test results, adhesion test records, salt-spray reports where specified, and visual inspection criteria | Do not accept “chrome plated” as sufficient evidence without a defined coating system and inspection method. |
| Dimensional Accuracy | Port size, thread or flange dimensions, face-to-face length, stem geometry, and mounting interfaces | Dimensions must conform to the agreed drawing and relevant thread, flange, or connection standard. | Inspection plan, calibrated measuring equipment list, first-article inspection report, and sample dimensional report | Require documented control of critical dimensions and revision-controlled drawings. |
| Pressure and Leakage Testing | Shell test, seat test, operating test, and allowable leakage | ISO 5208 and EN 12266-1 provide valve pressure-testing and leakage-testing frameworks. Test pressure, duration, and acceptance class must be stated in the purchase specification. | Batch test records, test equipment calibration certificates, test procedure, and nonconformance records | Prefer 100% final pressure testing when required by the product specification or risk level. |
| Potable-Water Compliance | Material safety, extractables, contamination control, and regional approval | For drinking-water applications, use the applicable market requirement, such as NSF/ANSI/CAN 61 in North America or the relevant national water-contact regulation in the destination market. | Valid product certification, scope of approval, laboratory reports, and confirmation that the exact model and materials are covered | Treat certification as model- and material-specific; do not rely on an uncertified factory-wide claim. |
| Quality Management System | Control of purchasing, production, inspection, corrective action, and document retention | ISO 9001 is the internationally recognized standard for quality management systems. Certification should be current and issued for the relevant manufacturing scope. | Current certificate, certification scope, issuing body, audit validity, quality manual summary, and corrective-action process | Verify the certificate independently and confirm that production activities are included in its scope. |
| Machining Capability | CNC turning, drilling, threading, deburring, process control, and repeatability | The supplier should demonstrate capacity for the required valve sizes, tolerances, materials, and annual volume rather than listing equipment without capacity data. | Equipment list, machine capacity, maintenance records, process-flow chart, capability studies, and production samples | Assess actual throughput, bottleneck operations, and subcontracted processes. |
| Plating Production Control | Cleaning, activation, plating-bath control, rinsing, drying, and wastewater management | Critical bath parameters must be monitored according to the approved plating process. Environmental controls must comply with applicable local requirements. | Process flow, bath-monitoring logs, chemical control records, maintenance records, and plating inspection reports | Prefer controlled in-house plating or a fully disclosed, audited plating partner with clear responsibility for quality. |
| Traceability | Link between raw materials, machining batch, plating batch, assembly, testing, and shipment | Traceability depth should match the risk and regulatory requirements of the application. | Lot codes, traveler sheets, serial records where applicable, inspection reports, and shipment records | Reject suppliers unable to identify the material and test history of a delivered batch. |
| Inspection and Testing Equipment | Pressure testers, torque testers, coating-thickness gauges, dimensional tools, and calibration controls | Measuring equipment must be suitable for the required accuracy and maintained under a documented calibration system. | Calibration certificates, equipment register, calibration intervals, and sample test records | Give higher scores to suppliers with calibrated equipment available at the production site. |
| Production Capacity and Lead Time | Monthly output, available shifts, bottleneck capacity, raw-material availability, and peak-season planning | Capacity claims should be supported by production records and should distinguish standard products from customized products. | Capacity plan, recent production schedule, on-time-delivery data, inventory policy, and contingency plan | Compare confirmed capacity against forecast demand, not only the supplier’s maximum theoretical output. |
| Product Consistency | Dimensional repeatability, operating torque, plating appearance, leakage rate, and defect rate | Acceptance criteria must be agreed before mass production and applied consistently across the batch. | Pre-production sample approval, first-article report, control plan, statistical inspection data, and defect analysis | Approve production only after samples pass the same tests required for mass-produced units. |
| Packaging and Corrosion Protection | Protective caps, anti-tarnish measures, moisture control, carton strength, and palletization | Packaging must prevent impact, contamination, and corrosion during the agreed transport and storage period. | Packaging specification, drop or transport test results where applicable, photos, and packing-list format | Confirm that chrome surfaces and valve threads are physically protected before shipment. |
| Audit and Sample Approval | Factory audit, process audit, sample testing, and corrective-action response | Supplier qualification should include document review, production observation, sample inspection, and closure of identified nonconformities. | Audit checklist, corrective-action report, sample test results, and approval record | Select suppliers that can provide objective evidence rather than relying solely on marketing claims. |
