Spherical-annular blowout preventer having a plurality of pistons

摘要

A blowout preventer includes a housing (5, 10) including interconnected cylinders (160) formed therein, a main seal (25) positioned within the housing (5), cylindrical sleeves (250) removably placed within the interconnected cylinders (160), annular pistons (40) and glands (45) placed within the sleeves (250); and an energizing ring (215) configured to be operated on by the annular pistons (40) in order to operate the main seal (25). A blowout preventer may also include an upper gland assembly (245) for isolating a void space (230) within the housing (10) from the interconnected cylinders (160).