... corrosion resistant alloy. Specification:Item Size Specification 1 9″ Single Ram BOP/Double Ram BOPBore: 9″ Working pressure: 10,000-15,000psi ... Bottom connection: 9″ 6BX BX157 CRA Flanged 3 11″ Single Ram BOP/Double Ram BOPBore: 11″ Working pressure: 10,000-15,000psi ... 6BX BX158 CRA Flanged 7 13 5/8″ Single Ram BOP/Double Ram BOPBore: 13 5/8″ Working pressure: 10,000- ...