The flanges in a pressure vessel or piping system are one of the most frequent sources of problems and/or leakages. The design of flanges including the bolts and gasket is difficult. The flange assembly is a complex mechanical item that requires some years of engineering and field experience. Furthermore, the calculation codes are not always providing uniform answers for the design verification.

FLG is the Red-Bag flange calculation software. The software provides calculations for standard and custom flange as per the ASME VIII div.1, the EN 13445-3 and the EN 1591-1 calculation codes. Flange types are circular with inner bolt circle gasket flanges.

The FLG application provides the engineer a flexible engineering tool to review, check and validate new and existing flange design. The available calculations give the engineer the opportunity to make different calculations and compare the results. This 'multi' calculation approach to flange design supports the engineer assessing the critical aspects of the flange assembly.

Some of the questions an engineer will get when a flange is malfunctioning are:

  • Is the flange overstressed, do I have to change the design?
  • Is the gasket overstressed, or is there not enough seating stress?
  • Is there enough bolt load in the flange, did we use the correct bolt torque?
  • Are the bolt providing enough flexibility during operation?
  • Did we select the correct gasket?
  • What is the leak tightness of the gasket with the given bolt load?

These are question or at least aspects considered by the engineer when designing a custom flange or determining the bolt load for piping flanges. For pipe flanges the following might also be the case:

  • Is there too much gap between the flanges?
  • Is there an unacceptable misalignment between the flanges?
  • Are outside forces considered?

Use the consultancy services from Red-Bag if you need support or require an expert opinion. The ultimate goal is to have the flange assembly as tight and safe as welding.