摘要 |
A pump for compressing a low temperature high density liquid gas, e.g. liquid helium, wherein the piston is driven by a motor through a four bar linkage which converts rotary motion to reciprocating motion. The pump also includes an improved piston ring assembly, piston venting apparatus and a cushioned discharge valve. A two-stage pump in combination with support equipment provides an improved pumping cycle wherein low temperature density liquid or gas e.g. liquid helium can be withdrawn from a storage reservoir, vaporized and compressed into cylinders.
|