Minimum bolt stress is primarily associated with maintaining what kind of seal?

• A. Gasket seating stress
• B. Bolt tensile strength
• C. Piping support loads
• D. Flange bending moment

Answer: (A)

When a bolted flange joint is assembled, the key to a good seal is creating enough contact pressure between the gasket and the flange faces. The minimum bolt stress represents the clamping force needed to seat the gasket properly, so the gasket can deform enough to fill surface irregularities and establish a seal. If the bolt load is too low, the gasket won’t seat, leaving gaps and potential leaks, even before the system is pressurized.

Bolt tensile strength matters for resisting peak loads and potential failure, but it does not define the initial seating of the gasket. External piping loads and flange bending moments influence the overall stability of the joint, but the sealing mechanism relies on achieving adequate gasket seating stress through proper bolt clamping.