In the structure, it is divided into annular blowout preventer with spherical plastic core, annular blowout preventer with cone-shaped plastic core, and blowout preventer with tube-shaped plastic core. Annular BOP top cap and housing are connected by bolts or claw blocks. Blowout preventer with spherical plastic core and dust-proof ring. Performance characteristics: reasonable structure, easy operation, long life of plastic core, adapt to a wide range, capable to seal pipe string with nominal paths from 0-DN in ans shapes, better performance by combining with ran blowout preventer in the use. Working Principle: When wells must be sealed in case of kicks high pressure (10.5Mpa) oil from control systems enters into close-cavity under piston from housing oil outlet, to promote plastic core moving upward along ball surface, so that bearing tendons move closer to each other to moce the rubber between them to the center of wellhead so as to seal drilling tools or fully seal wellhead. In opening , hydraulic pressure oul enters into open-cavity above piston from housing oul inlet, to push piston moving downwards , so that plastic will reset with its own elasticity, wellhead will be open. When you have any demands on BOP, BOP ram, Ram Packers and packing element, freely contact me for best quotation. We can provide you various brand and type product.