Annular BOP is controlled by hydraulic system, while sealing the well, the hydraulic oil enter the closing chamber on the bottom of piston from the lower oil port of body to push the piston move up and force the spherical move upward centripetal, make the ribs close each other, the rubber is squeezed toward the wellhead, carry out the sealing drilling tools or sealing the wellhead.

◆ Use the spherical structure cover, there is no stress concentration while bearing pressure, the stress of body is evenly and easy to install and disassemble.
◆ The radial end face of the piston is type Z, the strike is short, the height is low and set up the wearing zone without machining.
◆ The sealing ring use lip ring, the using life is long.
◆ The storage of rubber in the spherical rubber is large, the sealing is reliable and long life.
◆ For the high anti-H2S BOP, all the parts which touch the well fluid is welded by high nickel base alloy, it can reach the anti-H2S effect can be achieved. ( For clients to choose)