摘要 |
A method of forming a valve seat having a resilient plastic insert received in a serrated groove of the seat. The insert is inserted into the groove and is pressed therein with a power driven ram to effect cold flowing of the insert into serrations in the sides of the groove. The insert is then subjected to hydraulic fluid at a relatively high pressure level to completely bottom the insert against the bottom of the groove prior to machining of a protruding sealing surface of the insert. The invention is directed additionally to another method which includes the step of swaging a lip into the insert to secure it in a non-serrated groove of a valve seat. Hydraulic fluid pressure is then applied to the insert to completely bottom it in the groove prior to installation of the seat in a valve body.
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