Technical Note SB52: Explosion flap isolation valves

Data proves explosion isolation flap valves are not always tested under real-world conditions, and as a result, many flap valves on the market won’t function as certified.

Recent test data gathered from Fike Corporation’s Remote Testing Facility has empirically proven that potential performance problems exist with many ATEX-certified explosion isolation flap valves, which are currently available for purchase and even installed in many Canadian facilities.

These flap valves technically comply with NFPA 69, which states that all explosion isolation flap valves must be third-party tested and certified.  However, all flap valves sold in Canada have been tested to EN 16447 – the testing standard that Fike has proven does not accurately represent real-world conditions which may be experienced by a flap valve during a deflagration.

Many of these flap valves are certified to protect against pressures for which they were not accurately tested, as seen in the following information.