... used to open and close BOP and relief valve while drilling operation. API 16D Surface BOP Control ... and close BOP and relief valve while drilling operation. It mainly consists of remote control panel, driller's ... 0~14MPa(0~2000Psi)5, Nitrogen charging pressure of accumulators: 7±0.7MPa(1000±100Psi)6, Air ... 65~0.8MPa(93~115Psi)7, Pressure range of pressure valve: 17.5~21MPa(2500~3000Psi)8, Hydro- ...