EN 11 – Round steel flanges according to EN 1092-1 – Calculation per DIN EN 13445-3 chapter 11 (Taylor-Forge method)

In general, DIN EN 13445-3, chapter 11 permits a calculation for internal and external pressure for the most different flange types and covers almost all possible designs:

  • Calculation under internal or external pressure
  • Flanges with either full face or narrow face gaskets
  • Flanges with O-ring gasket
  • Internal flanges
  • Split loose-flange
  • Seal-welded flanges

The geometry database includes:

  • Welding flanges, loose flanges, blind flanges
  • Welding neck flanges, slip-on and welding flanges
  • Threaded flanges, integral flanges
  • hub, lap

Modules included in the package: see price list

EN 12 – Bolted domed ends convex or concave to pressure DIN EN 13445-3 chapter 12

(requires EN11 module)

Recognised and proven methods for the design of bolted domed ends, with either full face or narrow face gaskets, and with the dome either convex or concave to pressure.

EN 15 – Calculation of rectangular pressure vessels according to DIN EN 13445-3 chapter 15

Module EN15 comprises calculation rules for the design of rectangular pressure vessels with and without reinforcements. The calculation takes into account stresses caused by internal overpressure. After entering the geometry and materials, the program determines the existing membrane and bending stresses and checks the geometric conditions and allowable stresses.

EN 16.04 / EN 16.05 – Local loads on nozzles in spherical and cylindrical shells DIN EN 13455-3 chapter 16.4 / 16.5

e.g. nozzles under force and torque with or without reinforcing disc

* Alternative: Stress calculation of nozzle loads with integrated FE method (module FEM)

EN 16.06 – Line loads according to DIN EN 13445-3 chapter 16.6

contains general requirements for the calculation of axially symmetrical containers which are exposed to a local line load in the longitudinal or circumferential direction.

EN 16.07 – Lifting lugs acc. to DIN EN 13445-3 chapter 16.7

Lifting lugs on cylindrical shells and domed ends

The program calculates lifting lugs in longitudinal arrangement or in circumferential direction with or without reinforcement plate. The strength check for the weld seam and the lug is carried out according to RKF – guideline catalogue strength BR A 62.

EN20 – Reinforcement of flat walls according to chapters 20 and 21

The EN20 module calculates reinforcements of flat walls acc. EN 13445-3 chapter 20 and radial reinforcement ribs of round flat ends acc. chapter 21.

The program is divided into 3 calculation sections:

  • 20 Stayed flat walls
  • 21.4 Radially reinforced flat round ends without peripheral moment
  • 21.5 Radially reinforced flat round ends with peripheral moment

Three types of stays can be selected for the calculation of stayed flat walls: 20.6 Threaded staybolts, 20.7.1 Welded-in staybolts and 20.7.2 Welded stays. Radial reinforcement ribs for circular flat ends with and without centering ring can be calculatede acc. section 21. For ends with peripheral moment the bolt force is considered, which can be calculated with module EN10 for circular flat ends, with module EFL acc. section 11 or module 1591 acc. Appendix G (flanges). The geometrical conditions are indicated in the calculation mask. The strength conditions are checked after all required values have been entered.

Allowable external pressure for pressure vessels with out-of-roundness exceeding tolerance according to DIN EN 13445-3, Annex F

(incl. UNRD module)

Method for determining the permissible pressure for cylindrical shells whose out-of-roundness, measured from the true centre point, is more than 0.5% of the radius.

The included module UNRD is based on DIN EN 13445-3 Annex E

ENAJ – Alternative method for the design of heat exchanger tubesheets DIN EN13445-3 Annex J (Alternative to chapter 13)

The procedure applies to the following types:

  • U-tube heat exchangers, also heat exchangers with tubes with end caps and only one tube sheet, but also heat exchangers with curved tubes and any number of separate tube sheets
  • Heat exchanger with submerged floating head
  • Heat exchanger with externally sealed floating head
  • Heat exchanger with internally sealed floating head;
  • Fixed-head heat exchanger with expansion joint
  • Fixed-head heat exchanger without expansion joint


  • Calculation of non-symmetrical tube sheets (tube sheets 1 and 2 are different)
  • Calculation of tube sheets with untubed fields whose size exceeds the limitation according to EN 13445-3 chapter 13.

ENAO – Physical properties of steels acc. to DIN EN 13445-3 Annex O

Annex O applies to the most frequently used steels

After entering the boundary conditions (temperatures), geometric quantities (lengths) and density, the program determines the following physical properties at the entered temperature:

  • Modulus of elasticity ET
  • Linear thermal expansion βT
  • Thermal conductivity λT
  • Density at temperature T ρT
  • Specific heat capacity cT

With the help of the relationships of the differential properties to the property at reference temperature, it is possible to determine the properties of the frequently used steels at any temperature. These are additionally calculated by a polynomial.


In the module WRC / WRCK a calculation option according to the finite element method was integrated for the calculation of stresses in cylinders and spherical shells with nozzle loads.

The nozzles can be arranged with / without reinforcement disc, vertically, obliquely or tangentially.

Prices of the individual modules see price list

see also:

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