Questions regarding the valve material
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I would like to ask: for condensate containing a small amount of chloride ions, at a temperature of 90–110°C, with 316 being the initially chosen material, what materials should be used for the body, ball, and seat of the ball valve? What I’m mainly confused about is which part of the valve the valve seat refers to; it would be helpful if there were an illustration to show this.
If the valve body is 316, the ball can be made of 316 as well, and the valve seat can be made of RPTFE
Thank you very much. I have another question: for a globe valve whose operating medium is fresh steam at around 200 degrees, what material should be used for the valve seat? Should PTFE or 304 steel with flexible graphite be used?
Directly use duplex steel F53
Common valve seat materials and their applications: 1. EPDM (Ethylene Propylene Diene Monomer): It possesses excellent resistance to weathering, ozone, heat, acids and alkalis, water vapor, color stability, electrical properties, oil impregnability, and fluidity at room temperature. EPDM products can be used for extended periods at 120°C, and can be used for short periods or intermittently at 150–200°C. 2. NBR (Nitrile rubber): It is produced by the emulsion polymerization of butadiene and acrylonitrile. Nitrile rubber is mainly manufactured using low-temperature emulsion polymerization; it boasts excellent oil resistance, high wear resistance, good heat resistance, and strong adhesion. Its disadvantages are poor low-temperature resistance, poor ozone resistance, inferior electrical properties, and slightly low elasticity. 3. PTFE (polytetrafluoroethylene): It can be used continuously at 260°C, with a maximum operating temperature of 290–320°C. It features an extremely low coefficient of friction, good wear resistance, and excellent chemical stability. It cannot be injection molded; it can be extruded or coated. The unique properties of PTFE enable its wide use in industries such as chemicals, petroleum, textiles, food, papermaking, medicine, electronics, and machinery, as well as in marine operations. 4. Metal seal (cemented carbide): The material used for the metal-sealed valve seat possesses excellent properties such as high temperature resistance, high pressure resistance, corrosion resistance, and wear resistance. However, it requires sophisticated manufacturing processes; its biggest drawback is that leaks can occur over time due to prolonged operation.