When installing a housing with multiple bolt holes, which practice is correct?

When installing a housing with multiple bolt holes, which practice is correct?

• A. Tighten the bolts in a star pattern
• B. Install all bolts before tightening any bolt
• C. Tighten each bolt to final torque sequentially
• D. Leave one bolt loose until others are tightened

Answer: (B)

Starting with all bolts in place allows the parts to align evenly so the gasket seats properly. The best practice is to slip all bolts into their holes loosely first, then tighten them in a balanced pattern (often a cross or star sequence) to the final specified torque. This distributes the clamping force around the entire flange, prevents distortion of the housing, and helps ensure a proper seal. Tightening bolts one by one to final torque, or leaving one bolt loose until the others are tightened, can pull or tilt the joint and lead to leaks or misalignment.

Starting with all bolts in place allows the parts to align evenly so the gasket seats properly. The best practice is to slip all bolts into their holes loosely first, then tighten them in a balanced pattern (often a cross or star sequence) to the final specified torque. This distributes the clamping force around the entire flange, prevents distortion of the housing, and helps ensure a proper seal. Tightening bolts one by one to final torque, or leaving one bolt loose until the others are tightened, can pull or tilt the joint and lead to leaks or misalignment.