back-pressure valve


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back-pressure valve

[′bak ‚presh·ər ‚valv]
(petroleum engineering)
A check valve installed in a natural-gas well bore to shut off gas flow while replacing the blowout preventer (used during drilling) with a christmas tree piping arrangement, which controls gas flow out of the completed well.

check valve, back-pressure valve, reflux valve

check valve
An automatic valve which permits liquid to flow in only one direction. Also see non-return valve.