Engineering task and calculation objective
FLEN is an auxiliary module of the LV calculation environment from the family of general-purpose modules. It is not maintained as a standalone calculation with its own input mask, but works in conjunction with other modules to which it supplies intermediate results.
Such background modules are common in modular calculation systems: they encapsulate sub-calculations shared by several main modules and thus keep the actual design modules lean. The documentation of the results takes place in the main module that calls FLEN.
Calculation workflow
- Invocation by a main module: FLEN is driven in the background by a higher-level calculation module, from which it receives the required input data.
- Perform the sub-calculation: The module carries out its sub-calculation with the data handed over; no separate input by the user is intended.
- Return the results: The results are passed back to the calling module and incorporated there into the overall calculation and the documentation.
Input quantities
| Quantity | Symbol | Unit |
|---|---|---|
| Load case | case | – |
| Calculation temperature | t | °C |
| Calculation pressure | P | MPa |
| Material | end | – |
| Wall thinning allowance | δe | mm |
| Corrosion allowance | c | mm |
| Thinning allowance during manufacturing | δm | mm |
| Total allowance | ∑(δ) | mm |
| Nominal design stress (operation, exception) | f | MPa |
| Material strength, test | Ktest | MPa |
| Safety factor, test | Stest | – |
| Material strength (operation, exception) | K | MPa |
| Safety factor, operation | S | – |
| Reinforcement area | A | mm² |
| Smaller diameter of non-circular end | a' | mm |
| Greater diameter of non-circular end | b' | mm |
| Shape factor | C1 | – |
| Shape factor C2 from 10.4-5 | (0 ... 1) C2 | – |
| Shape factor C3 according to construction | C3 | – |
| Coefficient C4 from Fig.10.7-4 for narrow-face gasket | C4 | – |
| Distance between gasket and bolt circle | c | mm |
| Equivalent diameter of flat end with hub | Deq | mm |
| Diameter of the flat part | DF | mm |
| Inside diameter | Di | mm |
Calculation options
Type
Flat end with a hub of uniform thickness acc. Fig. 10.4-1a) · Flat end with a tapered hub acc. Fig. 10.4-1b) · Flat end welded directly to the shell acc. Fig. 10.4-2 · Flat end with relief groove acc. Fig. 10.4-3
Type of gasket
Flat end with a narrow-face gasket acc. Fig. 10.5-1 · Flat end with full-face gasket acc. Fig. 10.5-2
Type of flat end connection
Cylinder with welded flat end · Cylinder with bolted end
Type of opening
Opening without nozzle · Opening with set-on nozzle according Fig. 10.6-3 · Opening with set-in nozzle according Fig. 10.6-4
Type of end
Welded end · Bolted rectangular end with full-face gasket · Bolted elliptical or obround end with full-face gasket · Bolted end with narrow-face gasket · Annular welded or bolted end
With hub?
No · Yes
Frequently asked questions
Why does the module have no input mask of its own?
FLEN is designed as an internal calculation module. It obtains all input quantities from the calling main module and returns its results there; direct operation by the user is not required.
Where can I find the results of this sub-calculation?
In the documentation of the main module that uses FLEN. There, the supplied intermediate values are reported in the context of the overall calculation.