Patent ID: 8657253

Claim:
A blowout preventer (BOP) system, comprising: a blowout preventer comprising: a pair of ram blocks configured to seal a vertical bore; a pair of pistons, each connected to a corresponding one of the pair of ram blocks; and a pair of ram locking mechanisms, each positioned to lock a corresponding one of the pair of ram blocks in a closed position for sealing the vertical bore; a position sensing mechanism, configured to determine a current position of one or both pistons of the pair of pistons or one or both ram blocks of the pair of ram blocks; and a controller configured to perform the following operations to determine if a backlash is present in one of the pair of ram blocks, comprising: receiving data indicating the current position of the piston; determining the current position of the piston after the ram locking mechanism locks the ram block closed and the closing pressure is released; calculating a difference between the current position of the piston and a reference position of the piston, wherein the reference position is determined when the ram block is closed, the closing pressure applied to the ram block is released, and components of the ram locking mechanism are not worn; comparing the difference with a predetermined value; and providing data to display an indication that backlash is present when so occurring based upon results of the operation of comparing.