Comparison of hard sealing materials and soft sealing materials

Hard seals and soft seals can complement each other. Soft seals are relatively good in terms of tightness, but now the tightness of hard seals can also meet the corresponding requirements. The advantages of soft seals are good sealing performance, but the disadvantages are easy aging and wear. , Short service life. The hard seal has a long service life, but the sealing performance is relatively poorer than that of the soft seal.

Soft seal: One side of the seal pair is made of metal material, and the other side is made of elastic non-metallic material, which is called "soft seal". This kind of seal has better sealing performance, but it is not resistant to high temperature and easy to wear. Mechanically poor. Such as: steel + rubber; steel + PTFE, etc.

Soft seal means that one side of the seal pair is made of materials with relatively low hardness. Generally speaking, the soft seal seat is made of non-metallic materials with certain strength, hardness and temperature resistance. It has good sealing performance and can achieve zero leakage. , but the life and temperature adaptability are relatively poor. The hard seal is made of metal, and the sealing performance is relatively poor, although some manufacturers claim that it can achieve zero leakage. The soft seal cannot meet the process requirements for some corrosive materials, and the hard seal can solve it!

Hard seal: Both sides of the seal pair are made of metal materials or other hard materials, which are called "hard seals". This kind of seal has poor sealing performance, but has high temperature resistance, wear resistance and good mechanical properties.

Both soft and hard seals have their own advantages and disadvantages:

Advantages of soft sealing: The sealing performance can reach grade 6, and the maintenance and replacement of the valve seat is convenient. The valve torque is small, which can save the cost of the actuator. The manufacturing cost is low, the processing is cheap, and the lead time is short. Generally used for relatively clean, low viscosity liquids and gases. The disadvantage is: not resistant to high temperature, not wear-resistant.

Advantages of hard sealing: The valve core and valve seat can be combined in many ways. The application of surface spraying technology makes the valve have a good application in wear-resistant, high-temperature and corrosion-resistant conditions, and has a long service life. Disadvantages: high manufacturing cost, maintenance and replacement of valve core and seat usually require overall grinding, and inconvenient on-site maintenance. The valve torque is also relatively large.

Post time: May-07-2022