Duplex Check Valves

Weidouli offers a comprehensive range of high quality duplex check valves for all types of applications and industries. As for dual plate check valves, they have JB/T 8937 & API 594 design, wafer type. As for the end connections: Flange RF, Wafer & Lug are all standard units.

The other available type of Weidouli Duplex check valves includes Duplex pressure seal check valve, Duplex nozzle check valve, Duplex single plate check valve, Duplex lift type check valve, Duplex swing check valve.

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Duplex Check Valves

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Duplex Check Valves

Material Definition Of Duplex Check Valves

Duplex stainless steel is a steel that has half of the ferrite phase and half of the austenitic phase in its quenching structure, and generally, the minimum phase content must be up to 30%.

Material Features Of Duplex Check Valves

Corrosion Resistance

Excellent general corrosion resistance; superior to Stainless steel in most environments. Excellent resistance to localized corrosion including intergranular, pitting, and crevice corrosion; the CPT of Duplex steel is generally at least 35ºC. The grade is also resistant to chloride stress corrosion cracking (SCC) at temperatures of up to about 150ºC. Duplex steel will often perform well in environments that cause premature failure of austenitic grades. It has better resistance to seawater than Stainless steel.

Heat Resistance

Although Duplex steel has good high-temperature oxidation resistance, this grade - like other duplex stainless steels - suffers from embrittlement if held for even short times at temperatures above 300ºC. If embrittled, this can only be rectified by a full solution annealing treatment. Duplex stainless steels are almost never used above 300ºC.

What is the Difference Between a Single Check Valve and a Duplex Check Valve?

A single check valve protects against the risk of backflow and back-siphonage