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2, the cavity adopts the pressure self-tight sealing structure, during hydraulic test or operation, can use the medium pressure to compress the sealing ring to achieve reliable sealing, and the higher the pressure, the more reliable the sealing.

3. The valve body adopts high-quality steel castings, both ends of which are processed into U-shaped groove and directly butt welding with pipes. The chemical composition and properties of the two materials are similar, and the welding performance is excellent, without welding the intermediate itD;The four-open ring adopts 38CrMoAlA to resist nitriding, ensure its thermal strength, wear resistance, corrosion resistance, scratch prevention, easy to disassemble and assemble;Middle cavity self-sealing washer, high temperature steam corrugated asbestos washer, internal braid 18-8 filament to ensure sealing and prolong service life;Surface welding 1Cr18Ni9Ti, anti-rust, anti-erosion, multiple tests can ensure the seal.