The engineering task
A flanged joint carries a hot pressurised fluid and must maintain a specified tightness class through assembly, pressure test, heat-up and steady operation. Flange, bolts and gasket change stiffness and strength with temperature; external pipe forces and moments may unload or locally overload the sealing faces.
A simple flange-strength check is insufficient. Assembly preload must cover seating, relaxation and operating losses without overstressing gasket, bolts or flange during tightening. EN 1591-1 is therefore applied as a linked sequence of load cases rather than one operating point.
Required design data
- Flange geometry, materials and temperature profile
- Gasket parameters including Qsmax, Qmin and leakage data
- Bolt material, preload scatter and assembly method
- Pressure plus external axial forces and moments for each case
Technical solution approach
Define the joint
Capture flange dimensions, bolts, gasket and materials as one consistent connection system.
Set the tightness target
Translate the required leakage class into minimum required gasket stress.
Calculate assembly
Bound target preload and scatter between required gasket stress and allowable component loads.
Verify the load sequence
Calculate test, heat-up, operation and cooldown in their actual sequence with pressure, temperature and external loads.
Derive assembly instructions
Convert allowable preload into tightening method, torque or controlled bolt load and inspection requirements.
Expected deliverables
Suitable SOL ALPHA modules
The modules form a technically plausible toolchain. Their final selection and sequence will be confirmed during the later calculation against the applicable code and project conditions.