Patent ID: 6935610
Filing Date: 2005-08-30
Classification: F16K

Abstract:
1. In a partial stroke valve test apparatus having a housing enclosing a drive cam operably attached through a shaft to an actuator and an emergency shutdown valve, and an engagement cam attached to a cylindrical engagement shaft for selectively engaging with the drive cam during a partial stroke valve test and selectively rotated between a test position in which the engagement cam engages with the drive cam and an operational position in which the engagement cam is rotated away from the drive cam, the improvement comprising: a detent radially communicating with the engagement shaft for selectively maintaining the partial stroke valve test apparatus in the test position or the operational position; and a key for selectively rotating the drive cam, a key lock pin mounted in the housing, and a lock pin channel comprising a portion of the key wherein the key lock pin engages the lock pin channel, thereby preventing removal of the key from the valve test apparatus when the engagement cam is in the test position.