| The production of household air-condition increased sharply in China these years, in among, almost was heat pump air-condition. Compare to single-refrigerator air-condition,4-way reversing valve is a key item in heat pump air-condition. Under the electromagnetic effect, 4-way reversing valve can change the flow direction of refrigerant, which makes air-condition cooling in summer and heating in winter. 4-way reversing valve is the most complex and precision part besides compressor, so the refrigerant will leak, and the valve can't reverse totally, if the sealing instability happens.Because of environment protection, R410A is taking the place of HCFC22 obviously, the market of R410A air-condition expands. As the highest operation pressure of R410A raised 60% as well as the requirement of reliability and life for air-condition rising, the development of sealing materials in 4-way reversing valve is necessary.This paper discussed the reasons why PTFE is taken use of as a sealing material in 4-way reversing valve chemical stability, high and low temperature-resistant, low frictional coefficient and self-lubricating property. In order to cover the shortcoming of PTFE, wear resistance, we give some relevant solutions: new PTFE formula. The test result showed that graphite, glass fiber and carbon fiber could improve the wear resistance of PTFE, graphite and glass fiber preferred economically. In order to cover another shortcoming of PTFE, creep, this paper indicated that higher molecule weight and smaller particle size of PTFE, processing technology update, copolymerization modification of PTFE could help sealing material increase anti-creep. So sealing property of 4-way reversing valve was developed basically, which was good to save the energy of the heat pump system.We got reliable data by acceptable test methods and operation, and compared them. This will contribute to develop better resistant new sealing materials for 4-way reversing valve manufacturers.
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