double valves

double valves

[¦dəb·əl ′valvz]
(petroleum engineering)
Two valves in series used as subsurface traveling or standing valves in wells, the dual arrangement being more reliable than a single valve.
References in periodicals archive ?
3 Y-adapter with double valves stopping - 2 400 pieces
The Fukuroi plant is one of the first to be equipped with a pneumatic-sender pressure vessel system, whereby a pressure vessel is installed underneath each of the three main scales, which is directly fed by the scale through DFWG double valves and air shut-off valves.