| Valve Application | Confirm the service medium, operating temperature, pressure, flow direction, installation position, and frequency of operation. | Select the valve type and materials according to the actual duty rather than using nominal size alone. | Approved datasheet, piping and instrumentation diagram, design pressure, design temperature, and service-medium specification. | High |
| Material Selection | Verify whether the body is grey cast iron, ductile iron, or another specified iron grade, and check pressure-temperature limitations. | Material grade, casting standard, pressure class, and corrosion protection must match the project specification and applicable code. | Material specification, chemical composition report, mechanical-property report, and casting identification records. | High |
| Applicable Standards | Check the standards used for design, face-to-face dimensions, flanges, pressure testing, and marking. | Common references include EN 1074 for water-service valves, EN 12266-1 or API 598 for pressure testing, and ISO 5211 for actuator interfaces where applicable. | Standards matrix, product drawings, compliance statement, and revision-controlled technical documentation. | Medium |
| Manufacturer Capability | Assess whether the factory controls casting, machining, assembly, coating, testing, and final inspection. | A controlled production route with documented subcontractor controls is preferable to an undocumented trading or assembly arrangement. | Process-flow chart, facility audit, equipment list, production capacity data, and approved subcontractor register. | High |
| Casting Process | Review pattern control, melting practice, pouring records, heat treatment where required, and defect prevention. | Use controlled melting and pouring procedures with defined chemical-composition limits and acceptance criteria for casting defects. | Furnace records, melt-batch identification, pattern-control records, casting inspection procedure, and nonconformance reports. | High |
| Dimensional Control | Verify body dimensions, flange drilling, face-to-face length, stem dimensions, sealing surfaces, and actuator mounting dimensions. | Critical dimensions should be checked against the approved drawing using calibrated measurement equipment. | Inspection plan, dimensional inspection report, calibrated instrument list, and approved manufacturing drawing. | Medium |
| Pressure Testing | Confirm shell testing, seat testing, test medium, test pressure, holding time, and leakage acceptance criteria. | Testing should follow the specified standard, such as EN 12266-1 or API 598, with no visible leakage beyond the applicable acceptance limit. | Pressure-test procedure, test chart or digital record, calibrated gauge certificate, test report, and serial or batch reference. | High |
| Functional Testing | Check opening and closing operation, travel stops, operating torque, handwheel or gearbox performance, and actuator compatibility. | The valve should operate smoothly through the complete travel without sticking, abnormal noise, or excessive torque. | Functional test record, torque measurement where specified, actuator sizing calculation, and operating instruction. | Medium |
| Sealing Materials | Verify elastomer, gasket, packing, and coating materials for compatibility with the service medium and temperature range. | Material selection should consider potable-water requirements, chemical exposure, temperature, pressure, and expected service life. | Material certificates, elastomer grade declaration, technical data sheets, and relevant drinking-water or chemical-compatibility approvals. | High |
| Corrosion Protection | Assess surface preparation, coating type, coating thickness, curing, holiday detection where applicable, and repair procedures. | The coating system should be defined by environment and service; dry-film thickness should be measured against the approved specification. | Coating procedure, surface-preparation record, dry-film-thickness report, batch certificates, and coating inspection checklist. | High |
| Quality Management | Evaluate control of documents, purchasing, production, inspection, calibration, corrective action, and customer complaints. | An ISO 9001-certified quality management system is useful, but the certificate should be checked for scope, validity, and issuing body. | Valid certificate, quality manual or process map, internal-audit records, corrective-action samples, and calibration register. | Medium |
| Inspection Planning | Determine which characteristics are checked during incoming inspection, in-process inspection, final inspection, and pre-shipment release. | Critical-to-quality characteristics should have defined inspection methods, sampling levels, acceptance criteria, and responsible personnel. | Inspection and test plan, control plan, sampling procedure, final release checklist, and inspection personnel qualifications. | Medium |
| Traceability | Trace each valve from purchase order and casting batch through machining, assembly, testing, coating, packing, and shipment. | A unique heat, melt, batch, lot, or serial number should link the product to material and test records. | Permanent body marking, nameplate, traveler, heat-number record, material certificate, pressure-test report, and packing list. | High |
| Material Certificates | Check that certificates identify the material, production batch, applicable standard, test results, and authorized approval. | Certificates should be consistent with the valve marking and traceable to the actual melt or casting batch supplied. | Mill or foundry certificate, chemical analysis, mechanical test results where applicable, and certificate-validation procedure. | High |
| Non-Destructive Examination | Determine whether visual, dimensional, dye-penetrant, magnetic-particle, ultrasonic, or radiographic examination is required by the design risk. | Use NDE selectively according to the governing specification, casting risk, pressure class, and customer requirement. | NDE procedure, personnel qualification, inspection report, equipment calibration record, and disposition of indications. | Medium |
| Sampling and Pre-Shipment Inspection | Define inspection quantity, sampling method, witness points, documentation review, and rejection procedures before shipment. | Use a documented sampling plan, with 100% checks for designated critical tests and agreed acceptance limits for visual and dimensional defects. | Inspection level, acceptance-quality-limit agreement, third-party inspection report if required, and signed release note. | Medium |
| Documentation Package | Confirm the complete data book required for customs clearance, installation, commissioning, and future maintenance. | The package should normally include drawings, operating instructions, certificates, test reports, coating records, spare-parts information, and packing details. | Document index, approved data book, revision history, certificate list, and digital archive structure. | Medium |
| Packaging and Logistics | Review protection of flange faces, stem and actuator components, internal surfaces, labels, moisture control, and container loading. | Packaging should prevent impact, corrosion, contamination, and loss of identification during multimodal international transport. | Packing specification, photographs before dispatch, moisture-protection record, packing list, and loading inspection report. | Medium |
| After-Sales Support | Assess warranty terms, spare-parts availability, technical response time, installation support, and failure-analysis capability. | Define warranty coverage, claim-response timing, replacement procedure, and responsibility for verified manufacturing defects in the purchase contract. | Warranty statement, spare-parts list, service procedure, escalation contacts, and sample corrective-action report. | Low |
| Commercial and Compliance Review | Check total landed cost, import duties, payment terms, export documentation, sanctions screening, and supply continuity. | Compare suppliers using total cost of ownership rather than unit price alone, including inspection, freight, documentation, and replacement risk. | Total-cost model, commercial offer, delivery schedule, export documents, compliance questionnaire, and business-continuity plan. | Medium |