Over the past few years there have been several cases of near-accidents due to leaks in flanges. Experience from offshore operation has shown that flanged connections in piping at high pressure in the presence of hydrocarbons constitute a large safety risk.
Better methods of avoiding leaks from such flanges will therefore provide a safety benefit, at the same time more effective methods of leak testing can reduce the down-time connected with testing, and thus reduce the loss in earnings as the result of downed production.
KaMOS® is now introducing a new method of leak testing of flanges with ring joints that can measure whether tightness has been achieved on all sealing surfaces of flange before the flange and pipe are subjected to internal pressure, as well as monitor the flange connections for future leakages.
The method permits flange integrity to be tested from the outside before system pressure is applied.
In the safety equation this will offer great benefits. It will also in many cases reduce the test time for normal pressure and leak tests because certain repetitions of the tests in case of leaky flanges would be avoided.
The test method is based on pressurizing the annular space above and below the seal ring using test gas. If no pressure loss is recorded during this pressurization, the seal is deemed tight.
The test gas that is applied to the annular space is applied using simple portable equipment, consisting of a gas reservoir, a manometer and hoses.
The equipment is easy to handle and will make it possible to test flanges on a one-off basis without pressurizing entire systems.
The test system will also check the primary and secondary sides of the seal for tightness.
The leak testing that is used today cannot distinguish these two sides, only if it’s tight or not.