摘要 |
A reciprocating compressor (26) includes two pistons (56 and 58) driven in opposite directions in a piston chamber (54). As a piston is driven in the downstream, compression-stroke direction, pressure causes a piston ring (64 or 66) that seals against the piston-chamber wall to seal against the piston, too, and thereby prevent fluid flow from the piston's downstream side to its upstream side. When the piston is driven downstream, on the other hand, pressure keeps the piston ring spaced from the piston and thereby allows flow from the piston's upstream side to its downstream side. The piston rings thus act as check valves.
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