Duplex Steel Check Valve Manufacturer & Exporter

ASTM A995 4A / A182 F51 (UNS S31803 / 2205) · 2" to 36" (DN50–DN900) · Class 150 / 300 / 600 / 900 · BS 1868 / API 594 / API 6D. Exported to Saudi Arabia, UAE & 40+ countries with full documentation.

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Why Duplex Steel for Check Valves?

Duplex Steel check valves combine the check valve's proven shutoff design with twice the yield strength of SS316 with far better chloride pitting and stress-corrosion resistance. This makes them the standard specification for seawater below 20°C, brackish water, brine, FGD systems, chemical processing, and offshore topside piping.

Supreme Valves manufactures duplex steel check valves in ASTM A995 4A / A182 F51 (UNS S31803 / 2205) with design and testing per BS 1868 / API 594 / API 6D. Every valve ships with EN 10204 3.1 material certificates and full pressure test reports; third-party inspection by Lloyd's, BV, or TÜV is available for project orders.

Duplex Steel Check Valve Specifications

ParameterSpecification
Body MaterialsASTM A995 4A / A182 F51 (UNS S31803 / 2205)
Corrosion IndexPREN 34–35
Temperature Range-50°C to +250°C
Size Range2" to 36" (DN50–DN900)
Pressure ClassClass 150 / 300 / 600 / 900
End ConnectionsFlanged RF/RTJ, Wafer, Lug, Butt Weld
Design StandardBS 1868 / API 594 / API 6D
TestingAPI 598, hydrostatic shell & seat; NDE (RT/PT/UT) on request
DocumentationEN 10204 3.1/3.2 MTC, NACE MR0175 compliance, IBR where applicable

Available Designs

Swing Check (Bolted Cover)
Dual Plate Wafer & Lug (API 594)
Piston / Lift Check
Non-Slam Spring Assisted
Retainerless Design Option
Soft or Metal Seated

Industries We Serve

Offshore oil & gas platforms
Desalination plants (GCC region)
Chemical & petrochemical plants
FGD & scrubber systems
Pulp & paper bleach plants
Marine & shipbuilding

Frequently Asked Questions

What duplex steel grades do you use for check valves?
We manufacture Duplex Steel Check Valve bodies in ASTM A995 4A / A182 F51 (UNS S31803 / 2205). All castings/forgings are supplied with EN 10204 3.1 material test certificates; 3.2 certification with Lloyd's, BV, or TÜV witness is available on request. PREN 34–35.
What services is a duplex steel check valve recommended for?
Duplex Steel construction is proven in seawater below 20°C, brackish water, brine, FGD systems, chemical processing, and offshore topside piping. The material offers twice the yield strength of SS316 with far better chloride pitting and stress-corrosion resistance. Operating temperature range is -50°C to +250°C.
What sizes, ratings, and designs are available?
Sizes 2" to 36" (DN50–DN900), pressure classes Class 150 / 300 / 600 / 900, end connections Flanged RF/RTJ, Wafer, Lug, Butt Weld. Designs include: Swing Check (Bolted Cover), Dual Plate Wafer & Lug (API 594), Piston / Lift Check, Non-Slam Spring Assisted. Design and testing per BS 1868 / API 594 / API 6D, pressure tested per API 598.
Do you export duplex steel check valves to the Middle East?
Yes. We export to Saudi Arabia, UAE, Qatar, Kuwait, Oman, and Bahrain with complete documentation — MTCs, test certificates, NACE MR0175 compliance where specified, and third-party inspection. Typical delivery 4–8 weeks with DAP/CIF terms to GCC ports.

Related Pages

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