API16A Blowout Preventers (BOP) and BOP Stacks Xi'An rig offers a range of annular and ram blowout preventers (BOPs) and BOP stacks for oil, gas, geothermal drilling, well intervention, and underbalanced drilling. Available in various models and specifications to meet industry standards. Xi'An rig provides a comprehensive selection of blowout preventers (BOPs) and BOP stacks, including annular BOPs with spherical and conical rubber cores and ram BOPs with U-type, UM-type, and