Improved cylindrical throttle valve

Valve seat sealing ring

20 transfer tray assembly for underbalanced drilling rotary assembly

20 ferrule casing head

20 mud umbrella assembly of environmental protection closed rotary BOP

Carbon dioxide silencing emission device

Carbon dioxide heating deep buried device

Automatic water make-up device for boiler of pressure injection equipment for carbon dioxide production

Rotary control head for underbalanced drilling with large shell

Penetration type tubing hanger positioning device

Ultra high pressure Non rising stem connecting mechanism

Indicating device of Non rising stem valve