There are various types of fillers for valves, and different fillers are suitable for different operating environments. The correct selection of fillers can increase the service life of the valve.

Introduction to the types and functions of commonly used valve fillers:


1、 Compressed packing

(1) Plant fiber filler

Made of hemp or cotton impregnated oil, wax, or other anti-seepage materials, used on low-pressure valves below 100 ℃. Suitable for media such as water and ammonia.


(2)Asbestos fiber filler

Asbestos fiber has good heat resistance, resistance to weak acids and strong alkalis, high strength, and good adsorption performance.


(3) Rubber filler

There are rubber cloth clips, rubber rods, and circular rubber fillers used in media such as ammonia and concentrated sulfuric acid with a temperature of ≤ 140 ℃.

(4) Carbon fiber filler

Carbon fiber filler is made of carbon fiber braided rope impregnated with polytetrafluoroethylene lotion. Carbon fiber fillers have excellent elasticity; It has excellent self lubrication and high temperature resistance, and can work stably in the temperature range of -120~350 ℃ in air, with a pressure resistance of ≤ 35MPa.

(5) Flexible graphite filler

Flexible graphite packing is widely used in valves and has the following excellent properties:

① With unique flexibility and resilience, the cutting filler can freely bend more than 90 ° along the axial direction, and will not leak due to temperature, pressure changes, vibration and other factors during use. Therefore, it is safe and reliable, and is an ideal sealing material.

② Good temperature resistance. Low temperature can be applied to -200 ℃, up to 500 ℃ in high-temperature oxidizing media, and up to 2000 ℃ in non oxidizing media, maintaining excellent sealing performance.

③ Strong corrosion resistance. Good corrosion resistance to acids, alkalis, organic solvents, organic gases, and vapors. Non aging, non deteriorating, resistant to corrosion from all media except strong oxidizing media (nitric acid), oleic acid, chromic acid, halogens, etc.

④ Low friction coefficient and good self lubrication.

⑤ Excellent impermeability to gases and liquids.

⑥ Long service life, reusable.

Flexible graphite is widely used in industries such as petroleum, chemical engineering, power generation, fertilizers, pharmaceuticals, papermaking, machinery, metallurgy, aerospace, and atomic energy. Flexible graphite fillers can generally be pressed and formed. Applicable nominal pressure ≤ 32MPa.

(6) Metal filler

According to its structure, it can be divided into metal foil winding filler, metal foil kneading and folding filler, metal waveform filler, lead wire twisting filler, and lead ring filler. The advantages of metal foil winding filler and metal foil wrinkling and laminating filler are high temperature resistance, erosion resistance, wear resistance, high strength, and good thermal conductivity. However, the sealing performance is poor and requires a high compression force, which must be used in conjunction with plastic fillers. Its usage temperature, pressure, and corrosion resistance depend on the metal material.

2、 V-shaped packing

The V-shaped packing is composed of upper packing, middle packing, and lower packing. The upper and middle fillers are made of polytetrafluoroethylene or nylon, while the lower fillers are made of materials such as 1Cr13, 1Cr18Ni9, and A3 steel. PTFE has a temperature resistance of 232 ℃, nylon has a temperature resistance of 93 ℃, and a general pressure resistance of 32MPa. It is commonly used in corrosive media.



3、 O-ring packing

The cross-section of the O-ring is circular, and its material is rubber, polytetrafluoroethylene, and metal hollow O-ring. The O-ring is not only used for static sealing, but also for dynamic sealing