Patent ID: 7637474

Claim:
A method for actuating a hydraulic blowout preventer operator comprising: supplying a volume of hydraulic fluid to a first extend chamber disposed within a first operator housing so as to move a closure member into a bore of a blowout preventer, wherein the first extend chamber is formed between one end of the first operator housing and the engagement between the first operator housing and a first end of a first piston, which comprises a flange and a flange seal; supplying a volume of hydraulic fluid to a first retract chamber disposed within the first operator housing so as to move the closure member out of the bore of the blowout preventer, wherein the first retract chamber is formed between an opposite end of the first operator housing and the engagement between the first operator housing a second end of the first piston, which comprises a body and a body seal; and wherein the first end of the first piston comprises a larger diameter than the second end of the first piston such that the volume of hydraulic fluid supplied to the first retract chamber to move the closure member out of the bore is less than the volume of hydraulic fluid supplied to the first extend chamber to move the closure member into the bore.