However, the intended use for a Flapvalve is always with a pipe on both sides. Therefore, a number of explosion tests, with a pipe connected on both sides of the Flapvalve, are needed.
Phenomenon observed during tests:
– The pressure in the pipeline opposite to the test vessel may be higher for a short period and can cause a failure and deformation of the locking device. Thus, it is be possible that a secondary explosion can pass.
– During experiments without an attached tube on the opposite side, this cannot be observed, as there is no vacuum but a difference in the overpressure.
The very high oscillation size in the pipe comes from the strong closure of the flap which converts dynamic pressure into static pressure and produces shock waves. The oscillations are much smaller in the vessel.
So, in real use, it is likely that the pressure in the protected side may be transiently higher than the pressure on the unprotected side due to the high acoustic oscillations on both sides of the flap with considerable hazards of the possibility of glow and flames may pass, if the locking device is not prepared for a possible reopening and can lead to very dangerous effects.