Flanged Closure Checklist
Checklist for bolted flange closure assessment — pressure thrust, bolt load, gasket compression, flange rotation, leakage and fatigue.
Pressure thrust
- Pressure thrust calculated: F = p * pi * r^2
- Thrust direction confirmed (axial, tending to separate)
Bolt load
- Bolt preload specified
- Joint stiffness ratio calculated
- Bolt load increase from pressure estimated
- Residual bolt load at operating pressure confirmed
- Bolt stress within allowable
Gasket
- Gasket type and material specified
- Gasket compression at assembly calculated
- Gasket residual compression at operating pressure calculated
- Minimum sealing pressure confirmed
- Gasket unloading from flange rotation assessed
Flange rotation
- Flange moment calculated
- Flange rotation estimated or analysed
- Rotation within acceptable limits
- Gasket compression non-uniformity assessed
Fatigue
- Pressure cycling defined if applicable
- Bolt alternating stress calculated
- Bolt fatigue life assessed
FEA
- Nonlinear contact between flange faces modelled if FEA used
- Gasket nonlinear behaviour included if FEA used
- Bolt preload modelled as pretension or thermal contraction