Engineering guide
This module selects non-metallic flat gaskets to DIN EN 1514-1 — the dimensional standard for gaskets used with PN-designated flanges. For every combination of nominal diameter DN and nominal pressure PN, it delivers the inside and outside diameter and the gasket thickness, and derives from these the gasket mean diameter and the effective gasket width — the basic geometric quantities of every flange calculation.
In addition, the module provides the characteristic values needed for the tightness verification: minimum and maximum allowable surface pressure, gasket factor, creep factor, and the modulus of elasticity at 20 °C with its temperature-dependent alteration rate. This allows you to check whether the gasket is sufficiently compressed at operating pressure and operating temperature without being destroyed by excessive compression.
Typical applications are soft gaskets (e.g. fiber- or PTFE-based materials, graphite) in flanged joints of pressure equipment and piping systems. Anyone who wants to design a flat gasket to DIN EN 1514-1 gets dimensions and material properties from a single source here — as direct input values for flange verifications to DIN EN 1591-1 or AD 2000-Merkblatt B 7 of the German AD 2000 code.
Scope
- Non-metallic flat gaskets
Typical workflow
Select nominal size and pressure rating
From the nominal diameter DN and nominal pressure PN of the flanged joint, the appropriate gasket size follows; the operating pressure is assigned to the pressure rating.
Determine the gasket dimensions
The module reads the inside diameter, outside diameter, and thickness of the flat gasket from the dimension table of DIN EN 1514-1 and calculates from these the gasket mean diameter and the effective gasket width.
Assign the material properties
For the selected gasket material, the minimum and maximum compressive load (surface pressure), gasket factor, creep factor, and the modulus of elasticity at 20 °C with its alteration rate over temperature are provided.
Check suitability for the operating conditions
Operating pressure and operating temperature are compared with the allowable characteristic values: the surface pressure in the assembly and operating condition must lie between the minimum and maximum compressive load so that the joint remains tight and the gasket neither blows out nor is crushed.
Hand over the values to the flange calculation
Gasket mean diameter, effective width, and characteristic values flow as input quantities into the verification of the complete flanged joint, for example to DIN EN 1591-1.
Frequently asked questions
What is the effective gasket width needed for?
The gasket force is not distributed over the entire gasket area but over the ring area actually compressed between the sealing faces. Together with the gasket mean diameter, the effective width determines the area over which surface pressure and required bolt force are calculated — making it the central geometric quantity of the tightness verification.
Why is there a minimum and a maximum compressive load?
Below the minimum surface pressure, the gasket does not conform sufficiently to the flange surfaces and leaks; above the maximum pressure, the material is plastically destroyed or extrudes sideways. The assembly bolt force must be chosen so that the surface pressure remains within this window in all load cases — including after settling and creep.
What role do the creep factor and the gasket modulus of elasticity play?
Non-metallic gaskets relax under load and temperature: part of the assembly compression is lost through creep and settling. The creep factor describes this loss, and the temperature-dependent modulus of elasticity describes the elastic recovery capacity. Both characteristic values determine how much gasket force actually remains in the operating condition.
Does DIN EN 1514-1 also apply to Class-designated flanges (ASME)?
No, DIN EN 1514-1 applies to PN-designated flanges to DIN EN 1092. For Class-designated flanges, the sister standard DIN EN 12560-1 applies. The gasket dimensions differ because the sealing faces and bolt circles of the two flange systems are not identical.
Worked example
For a flanged joint DN 100, PN 16, the gasket mean diameter, the effective gasket width, and the compressed gasket area are to be determined from the dimensions of a flat gasket to DIN EN 1514-1 (form IBC, inside bolt circle) — a worked example of a basic gasket calculation.
Given
| Inside diameter di | 115 mm |
|---|---|
| Outside diameter da | 162 mm |
| Gasket thickness | 2 mm |
Solution
Gasket mean diameter
dG = (di + da) / 2 = (115 mm + 162 mm) / 2 = 138.5 mm
Effective gasket width
bG = (da − di) / 2 = (162 mm − 115 mm) / 2 = 23.5 mm
Here the full ring width is assumed to be compressed; in a calculation to DIN EN 1591-1, a smaller effective width may result from the force-deformation behavior.
Compressed gasket area
AG = π · dG · bG = π · 138.5 mm · 23.5 mm ≈ 10,225 mm²
This area is the reference quantity for the surface pressure: a bolt force of, say, 100 kN produces about 9.8 N/mm² of compression on it.
Result
| Gasket mean diameter dG | 138.5 mm |
|---|---|
| Effective gasket width bG | 23.5 mm |
| Gasket area AG | ≈ 10,225 mm² |
Technical content source: LV-Solved-Problems-Content 628d313247e7