摘要 |
<p>A check valve system (10) with a fail-safe valve (FSC) comprising either a pair of oppositely acting, oppositely facing, one-way check valves (V1 and V2) located at the interface (42) between two connecting numbers (36, 40), or a shuttle valve (206) and stab (232), for controlling the flow of fluid through the connector members at the member interface. Said valves (V1, V2, and 206) are closed by spring bias when the members are separated but which are mechanically opened when said members engage one another to permit the flow of pressure fluid through the members. The fail-safe valve (FSC or FSCa) is a one-way check valve in one of the check valves (V2) closed against pressure fluid, when said members are joined, but which will open to relieve any pressure which might be trapped in control lines (12a) when the members become disconnected. The members are disclosed as part of a connector (16) and a mandrel (20), and as part of a tree (200), tree cap (202 ), or running tool.</p> |