| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a relief valve for use in low pressure, having operating pressure free of great change from set pressure even after being left in an valve closed condition for a long time. <P>SOLUTION: The relief valve for use in low pressure to be operated at a pressure of 100KPa or lower comprises a valve element having an O-ring to be moved apart from or close to a valve seat. The O-ring is treated by surface treatment agent which contains a fluorine-containing compound shown in a general formula (1), a multifunctional alkoxysilane shown in a formula: Si(OR<SP>4</SP>)<SB>n</SB>R<SP>5</SP><SB>4-n</SB>, where R4 is an alkyl group, R5 is a hydrogen atom or a monovalent organic group, and n is an integer of 2 to 4, silane coupling agent, and solvent for dissolving these. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
