What is a butterfly valve seat?

The valve seat is called the sealing surface, which is the sealing part inside the channel of the butterfly valve body.

What is the butterfly valve seat material?

Seat soft seal material is rubber (natural, nitrile, EPDM, silicone rubber, fluorine rubber) and plastic (PTFE, polyolefin, polypropylene, nylon).

The seal ring is elastic and resilient, has stable performance, is not easy to dissolve in the medium, thermal contraction effect (Joule effect) is small. Mechanical hardware is commonly used in mechanical equipment, there are many materials.

NBR

Oil-resistant, heat-resistant, and wear-resistant while having good water resistance, airtightness, and excellent bonding

NBR seals: oil resistant, heat resistant, wear-resistant, and have good water resistance, air tightness, and excellent adhesion. For more applications in the oil pipeline, the disadvantage is that it is not resistant to low temperature, ozone, insulation performance is very poor, and the elasticity is also general.

Suitable for petroleum-based hydraulic fluids, diol hydraulic fluids, diester lubricants, gasoline, water, silicone grease, silicone oil, and other media. It is a very wide range of uses and low-cost rubber seals.

Not suitable for use as ketones, ozone, nitrocarbons, MEK, and other polar solvents.

The general operating temperature range is -40°C to 120°C.

HNBR

Excellent corrosion resistance, tearing and compression deformation characteristics, excellent ozone, sunlight, and weather resistance. Abrasion resistance is better than nitrile rubber. Suitable for washing machinery, automobile engine systems, and refrigeration systems manipulating the new environmentally friendly refrigerant R134a. Not recommended as a solution for alcohols, esters, and aromatics. The general manipulation body temperature limit is -40°C~150°C

Silicone

Excellent heat resistance, cold resistance, ozone resistance, and atmospheric aging resistance. Has excellent insulating properties. However, the tensile strength is worse than the general rubber, with no oil resistance. Suitable for electric water heaters, irons, microwave ovens, and other home appliances. It is also suitable for various products that come into contact with the human body, such as water bottles and drinking fountains. Do not use the most concentrated solvents, oils, concentrated acids, and sodium hydroxide. General manipulation of the body temperature limit of -55 ° C ~ 250 ° C.

VITON

Better heat resistance than silicone rubber, excellent weather resistance, ozone resistance, and chemical resistance, poor cold resistance. Resistant to most oils and solvents, especially acids, aliphatic hydrocarbons, aromatic hydrocarbons, and animal and vegetable oils. Suitable for sealing needs of diesel engines, fuel systems, and chemical plants. Not recommended for use as ketones, low molecular weight esters, and nitro-containing mixtures. General manipulation of the body temperature limit of -20 ° C ~ 250 ° C.

Fluorosilicone

The performance of both fluorine rubber and silicone rubber, oil resistance, solvent resistance, fuel oil resistance, and high and low-temperature resistance is excellent. Can resist the erosion of oxygen-containing compounds, solvents containing aromatic hydrocarbons, and chlorinated solvents. Used for aerospace, space, and military applications. Exposure to ketones and brake fluid is not recommended. General manipulation of the body temperature limit of -50 ° C ~ 200 ° C.

EPDM

Excellent weather resistance, ozone resistance, water resistance, and chemical resistance. Can be used as alcohols and ketones, and can also be used as high-temperature water vapor environment sealing. Suitable for use as a bathroom, automotive radiator, or automotive brake system. Not recommended for exposure to food use or mineral oil. General manipulation of the body temperature limit of -55 ° C ~ 150 ° C.

Compared with other general-purpose rubber, EPDM rubber has great advantages.

1. Very high-cost performance, in the commonly used rubber, EPDM raw rubber density is the lightest, and can do a lot of filling, reducing the cost of rubber.
2. EPDM material has aging resistance, withstands sunlight exposure, heat resistance, water vapor resistance, and radiation resistance, suitable for weak acid and alkali media. Good insulation performance.
3. Applicable temperature range, the lowest can be -40 ° C – 60 ° C, and can be used under the temperature conditions of 130 ° C for a long time.

Polytetrafluoroethylene (PTFE)

A fluorine plastic, this material has a strong resistance to acid and alkali, and resistance to a variety of organic solvent properties. At the same time, the material is resistant to high temperatures and can be used continuously at 260°C, and the maximum use temperature can reach 290-320°C. The emergence of PTFE has successfully solved many problems in the field of chemical, petroleum, and pharmaceutical industries.

 

Standard Size for butterfly valve Teflon seat

Inch	mm
2“	DN 50
2.5“	DN 65
3“	DN 80
4“	DN 100
5“	DN 125
6“	DN 150
8“	DN 200
10“	DN 250
12“	DN 300
14“	DN 350
16“	DN 400
18“	DN 450
20“	DN 500
24“	DN 600
28“	DN 700
32“	DN 800
36“	DN 900
40“	DN 1000

If you have any questions about the butterfly valve seat, please feel free to contact us.

We can help you solve the sealing problem.