High Pressure Clamps Best Value Vacs recommends tightening all High Pressure to their specified LBS of torque. We do not recommend tightening high-pressure bolts with an impact gun because this may cause threads to jump or be marred which can cause failure of the bolt or seal. Sizes Available: 1.5" High Pressure Clamp 2" High Pressure Clamp 2.5" High Pressure Clamp 3" High Pressure Clamp 4" High Pressure Clamp 6" High Pressure Clamp 8" High Pressure Clamp 10" High Pressure Clamp 12" High | BVV High Pressure Clamps.