LATCHING RECIPROCATING VALVE ASSEMBLY

摘要

A latching reciprocating valve assembly (10) capable of remaining in a closed mode of operation for all pressures of operation, and only moving to an open mode of operation once the pressure differential is reduced below a release pressure after having exceeding a predetermined minimum engagement pressure. The engagement pressure being greater than the release pressure. The latching reciprocating valve assembly uses a sliding port collar (26) and a sliding actuator (30) operating against a spring (38) to change between the closed mode and the open mode. The assembly (10) avoids the need for blow out plugs and shear pins that need to be replaced after each use and may be used in a tool (50) that is run into a core barrel (66) on a wireline for testing or maintenance or the like of a well.