| 摘要 |
A refrigeration valve body is formed by brazing front and back segments having front and back ports respectively, the back segment also having a distribution port and a charging port for the reception of pressurized freon gas to charge a related refrigeration system through the back port and the front and distribution ports. The back segment comprises an opening from its back end to the back port. After brazing of the segments a tool is inserted through said opening to dress a seat around the front port. The tool is then removed, and a valve stem and seat assembly is inserted into the opening. This assembly comprises a sleeve threaded into the opening to compress a sealing gasket against a collar which is in turn compressed against a shoulder of the back body segment in the back port. A valve stem is threaded into the sleeve extending through the gasket and collar and comprises a head with oppositely facing seats arranged for line contact with front and back seats around the front port and the front end of the collar, respectively. The collar has a passage from the charging port to the back seat. Preferably all threads are self-locking.
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