Valve sealing material is an important part of valve sealing. What are the valve sealing materials? We know that valve sealing ring materials are divided into two categories: metal and non-metal. The following is a brief introduction to the use conditions of various sealing materials, as well as commonly used valve types.
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 use temperature of synthetic rubber is t≤150℃, and the temperature of natural rubber is t≤60℃.Rubber is used to seal globe valves, rubber seated gate valve, diaphragm valves, rubber seated butterfly valve, rubber seated swing check valve (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 for ball valves and globe valves with temperature t≤90℃ and nominal pressure PN≤32MPa.
3. PTFE
PTFE is mostly used for globe 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 valve, globe valve, plug valve, etc. for temperature t≤100℃, nominal pressure PN≤1.6MPa, gas and oil.
5. Babbitt alloy
Babbitt alloy is used for ammonia globe valve with temperature t-70~150℃ and nominal pressure PN≤2.5MPa.
6. Copper alloy
Common materials for copper alloys are 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 often used in gate valves, globe valves, check valves, plug valves, etc.
7. Chrome stainless steel
The commonly used grades of chromium stainless steel are 2Cr13 and 3Cr13, which have been quenched and tempered, and have good corrosion resistance. It is often used in valves for media such as water, steam and petroleum with temperature t≤450℃ and nominal pressure 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, used for globe valve, ball valve, 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 valve with temperature t≤540℃ and nominal pressure PN≤10MPa.
10. Boronizing
Boronizing directly processes the sealing surface from the material of the valve body or disc body, and then carries out boronizing surface treatment, the sealing surface has good wear resistance. Used in power station blowdown valve.
Post time: Jun-10-2022
