Common material and service condition of valve sealing ring

Valve sealing ring materials are metal and nonmetal two major categories. Commonly used materials and their conditions are as follows:

1 synthetic rubber

Synthetic rubber is superior to natural rubber in oil resistance, temperature resistance and corrosion resistance. General synthetic rubber temperature is not higher than 150 DEG T, natural rubber t is less than or equal to 60 DEG C, rubber for the nominal pressure PN = 1MPa cut-off valve, gate valve, diaphragm valve, butterfly valve, check valve, valve valve sealing pipe clamp.

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2 nylon

Nylon has the advantages of small friction coefficient and good corrosion resistance. For t nylon temperature is not higher than 90 DEG, nominal pressure PN = 32MPa ball valve, globe valve etc..

3 PTFE

PTFE used for temperature T is less than or equal to 232 DEG C, nominal pressure PN = 6.4MPa cut-off valve, gate valve, ball valve etc..

4, cast iron

Cast iron used for temperature is not higher than 100 DEG T, nominal pressure PN is less than or equal to 1.6MPa, the gas and oil of the gate valve, globe valve, plug valves, etc..

5, Babbitt

Babbitt for globe valve, nominal pressure PN temperature t-70~150 = 2.5MPa ammonia.

6, copper alloy

Copper alloy commonly used materials are 6-6-3, tin bronze and 58-2-2 manganese brass. The copper alloy has good abrasion resistance, suitable for the temperature of T is less than or equal to 200 DEG C, nominal pressure PN is less than 1.6MPa of water and steam, commonly used in valve, globe valve, check valve, plug valve etc..

7 chromium stainless steel

Chromium stainless steel commonly used grades 2Cr13, 3Cr13, after quenching and tempering treatment, corrosion resistance is good. Commonly used in the T temperature is not higher than 450 DEG PN, nominal pressure equal to or less than 32MPa of water, steam and oil medium valve.

8 chromium nickel titanium stainless steel

Chrome nickel titanium stainless steel is commonly used in 1Cr18Ni9ti. Its corrosion resistance, erosion resistance and heat resistance are better. Apply to the temperature T is less than or equal to 600 DEG C, nominal pressure PN = 6.4MPa steam, nitric acid medium, for cut-off valve, ball valve and so on.

9 nitriding steel

The common grade of nitrided steel is 38CrMoAlA, and it has good corrosion resistance and scratch resistance after carburizing. Power station valve commonly used in the T temperature is not higher than 540 DEG, nominal pressure PN is less than 10MPa.

10 boronizing

Boronizing by the body or valve body material directly processing the sealing surface, and then boronizing surface treatment, sealing surface wear resistance is very good. Blowdown valve for power plant.