1,standardAPI 16A 2,Bore dia.7 1/16(180mm)26 3/4 ... BOP in the closed position, such operation as circulating drilling fluid, re-leasing pressure and killing the well can be special ... flanges, bolts, clamps and ring grooves all conform to API 16A Ram structureFor dual-face ram, the upper face and lower ... drilling tool with the same size as the ram. If long time of well close is necessary, the ram should be ...