Patent ID: 9085955
Filing Date: 2015-07-21
Classification: E21B,Y10T

Abstract:
1. An anti-rotation device for a stuffing box, the stuffing box comprising a housing with a threaded opening and a correspondingly threaded cap configured to seal the opening, the housing and the cap configured when threadably connected to retain packing in the housing under a pressure above ambient, the cap rotatable in a first direction to seal the opening and in an opposite second direction to unseal the opening, the pressure disposing the cap to rotate in the second direction and unseal the opening, the cap being provided with a protuberance on an outside edge thereof, the anti-rotation device comprising a stop member pivotably attached to the outside of the housing and extending at least adjacent the cap but is unbiased toward the cap, and a disengageable locking mechanism to selectively lock the stop member adjacent the cap, the stop member capable of pivoting away from the cap and the protuberance when unlocked and prevented from pivoting away from the cap and the protuberance when locked, such that upon rotation of the cap in the second direction by operation of the pressure the protuberance contacts the stop member and the cap is thereby prevented from further rotation in the second direction.