Our check valves are manufactured to API 6D and API 598 standards for testing and inspection. We also comply with ANSI B16.34 for pressure-temperature ratings, ISO 5208 for pressure testing, and MSS SP-61 for pressure testing of steel valves. All products carry CE certification and our factory maintains ISO 9001:2015 quality management certification. Additional standards like AWWA C508, EN 12334, and JIS B2071 can be met upon request.

Yes, we specialize in custom material solutions. For seawater applications, we offer Duplex 2205, Super Duplex 2507, Hastelloy C276, Inconel 625, and 6Mo stainless steel. We also supply titanium, Monel 400, and other specialized alloys for chemical processing, offshore, and marine applications. All materials come with 3.1 material certificates and can be verified by third-party inspection. Minimum order quantities vary based on material availability.

Every valve undergoes comprehensive testing per API 598 requirements: Shell pressure test at 1.5x rated pressure, seat leakage test with maximum allowable leakage rates, and backpressure test to verify closure integrity. We perform 100% dimensional inspection, material verification using spectrometers, and non-destructive testing when required. All tests are documented with certificates. Third-party inspection by SGS, Bureau Veritas, TUV, or Lloyd's Register can be arranged at customer request.

For vertical upward flow, we recommend lift check valves or dual plate wafer check valves as they provide reliable sealing against gravity. For vertical downward flow, swing check valves with proper spring assistance work best. Consider non-slam check valves for pump discharge lines to prevent water hammer. Flow velocity should be sufficient to fully open the valve - typically 3-5 ft/sec minimum. Our engineering team can perform flow calculations and recommend the optimal solution based on your specific pipeline configuration and operating conditions.

Yes, absolutely. We provide EN 10204 Type 3.1 material certificates for all metallic components, including chemical composition analysis, mechanical properties, and heat treatment records. Third-party inspection services are available through SGS, Bureau Veritas, TUV, Lloyd's Register, DNV, and other internationally recognized agencies. Inspection can cover dimensional verification, pressure testing, material verification, and manufacturing process witnessing. Additional documentation includes test certificates, dimensional reports, welding procedure qualifications, and traceability records. All services are charged separately and require advance arrangement.

Our minimum order quantity is flexible: 10 pieces for trial orders, 25-50 pieces for standard production, and 100+ pieces for best pricing. Standard lead times are 15-20 days for common sizes in carbon steel or stainless steel, 25-35 days for special materials or large sizes. Express delivery available in 7-10 days for urgent requirements (additional charges apply). Stock items for popular sizes (DN50-DN300, 150LB-600LB) can ship within 3-5 days. We maintain strategic inventory for distributors and can establish consignment programs for high-volume customers.

Comprehensive technical support is included with every order. Our services include: Application engineering and valve selection assistance, CAD drawings and technical specifications, installation guidance and commissioning support, troubleshooting assistance and maintenance recommendations. We offer 24/7 emergency support for critical applications, field service through authorized representatives, and spare parts supply with fast delivery. Our technical team includes licensed engineers with 15+ years valve industry experience, fluent in English for international customers.