Forging Hydril GK Type Annular BOP Blowout Preventer 11" Bore 5000psi Working Pressure

Basic actuation: Requires both opening and closing hydraulic pressure. Seal-off is achieved by applying hydraulic pressure to the closing chamber, which raises the piston and forces the packing element into sealing engagement with the drill pipes or open bore.

Well pressure assistance: After initial seal-off, well pressure helps maintain the seal (excluding 7-1/16"-15,000 and 20,000 psi models, which require sustained closing pressure).

Stripping operations: Drill pipe can be rotated and tool joints stripped through the closed packing element while maintaining a seal. Optimal packing element life is achieved by setting the closing chamber pressure to allow slight drilling fluid leakage for lubrication.

Control system compatibility: Works with any standard accumulator unit equipped with a separate pressure regulator valve for the annular BOP and sufficient accumulator volume.

Supplementary components: If the pressure regulator valve responds slowly, an accumulator (surge absorber) precharged to 50% of the required closing pressure should be installed in the closing chamber control line. For subsea operations, an accumulator in the opening chamber line may be added to prevent pressure fluctuations.