Abstract: A blowout preventer control system for use in well operations includes a BOP having at least one opening chamber and at least one closing chamber, and an operating power fluid source connected to the BOP opening and closing chambers by an opening conduit and a closing conduit, respectively. A valve controlled conduit is connected to the opening conduit to ensure drainage of power fluid from the opening chamber of the BOP. A three-way shuttle valve is connected into the closing conduit close to the BOP. The shuttle valve is provided with an inlet which is connected to the closing conduit and another inlet which is connected by a conduit to an independent BOP operating power fluid source. An outlet of the shuttle valve is connected to the closing chamber of the BOP.

Abstract: A method for use in connecting flanges of a tubular joint is disclosed. A uniform pressure is applied to the flanges of the joint up to a desired preselected, measurable compression after which the nuts and bolts used to secure the flanges together are made up hand-tight. The preselected compression applied to the flanges is then released.