How To Choose The Sealing Material of The Valve? Ten Types of Valve Sealing Materials

Valve sealing material is an important part of valve sealing. It serves as the direct contact surface of valve sealing. What are the valve sealing materials?

1.Synthetic rubber

The comprehensive properties of synthetic rubber such as oil resistance, temperature resistance, and corrosion resistance are better than those of natural rubber. Generally, the service temperature of synthetic rubber is t≤150℃, and that of natural rubber is t≤60℃. The rubber is used for sealing of stop valves, gate valves, diaphragm valves, butterfly valves, check valves, pinch valves and other valves with nominal pressure PN≤1MPa.

2. Nylon

Nylon has the characteristics of small friction coefficient and good corrosion resistance. Nylon is mostly used in ball valves, stop valves, etc. with temperature t≤90℃ and nominal pressure PN≤32MPa.

3. Polytetrafluoroethylene

PTFE is mostly used for stop valves, gate valves, ball valves, etc. with temperature t≤232℃ and nominal pressure PN≤6.4MPa.

4.Cast iron

Cast iron is used for gate valves, stop valves, plug valves, etc. with temperature t≤100℃, nominal pressure PN≤1.6MPa, gas and oil.

5.Babbitt alloy

Babbitt alloy is used for ammonia stop valves with temperature t-70~150℃ and nominal pressure PN≤2.5MPa.

6.Copper alloy

Commonly used materials for copper alloys include 6-6-3 tin bronze and 58-2-2 manganese brass. Copper alloy has good wear resistance and is suitable for water and steam with temperature t≤200℃ and nominal pressure PN≤1.6MPa. It is commonly used in gate valves, globe valves, check valves, plug valves, etc.

7.Chrome stainless steel

Commonly used grades of chromium stainless steel include 2Cr13 and 3Cr13, which have been quenched and tempered and have good corrosion resistance. Commonly used in valves for media such as water, steam and petroleum with temperatures t≤450°C and nominal pressures PN≤32MPa.

8.Chromium nickel titanium stainless steel

The commonly used grade of chromium-nickel-titanium stainless steel is 1Cr18Ni9ti, which has good corrosion resistance, erosion resistance and heat resistance. It is suitable for steam, nitric acid and other media with temperature t≤600℃ and nominal pressure PN≤6.4MPa, and used for stop valves, ball valves, etc.

9. Nitrided steel

The commonly used grade of nitrided steel is 38CrMoAlA, which has good corrosion resistance and scratch resistance after carburizing treatment. Commonly used in power station gate valves with temperature t≤540℃ and nominal pressure PN≤10MPa.

10. Boronization

Boronizing directly processes the sealing surface from the valve body or valve disc body material, and then performs boronizing surface treatment. The sealing surface has very good wear resistance. Used for power station blowdown valves.