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DETONATION FLAME ARRESTER

IN-LINE BI-DIRECTIONAL OVERDRIVEN (UNSTABLE) DETONATION FLAME ARRESTER

Series No. 25000E / 35000E

ATEX / CE /  ISO Approved according to the latest ATEX Directive and ISO Standard 16852

Series No. 25000E / 35000E- Suitable for use with ISO Group IIA vapors, generally equivalent to National Electrical Code (NEC) Group D vapors

The Protectoseal Series Nos. 25000E & 35000E Detonation Flame Arresters are specifically designed to withstand and arrest the high velocity and high pressure flame fronts that may develop in long or complex piping runs such as those encountered in vapor recovery or manifolded tank systems. The arresters provide positive protection against flame transmission through piping systems handling chemical vapor mixtures as referenced below:

Protectoseal's Series 25000E / 35000E Detonation Flame Arresters are designed to withstand deflagrations (subsonic), stable detonations (supersonic) and overdriven/unstable detonations (transitional). These arrester are bi-directional, capable of stopping a flame or detonation approaching from either direction in a piping system.

STABLE VS UNSTABLE DETONATION ARRESTERS

"Unstable" detonation arresters are required for safety in piping containing flammable vapors, as encountered in vapor recovery or manifolded tank systems.

A confined flame front will accelerate from the point of ignition, eventually reaching the speed of sound in a pipe run. During the unavoidable transition period from subsonic to sonic speeds, flame front pressures and velocities are far greater than before or after the transition (an unstable detonation).

Devices approved under ISO 16852 as "stable detonation arresters" (DET-3 or DET-4) have not been tested against the severe mechanical and thermal effects of multiple unstable detonations. The use of "stable detonation arresters" is based on the premises that: 1) it is unlikely that the unavoidable high pressure and velocity transition will occur as the flame front reaches the detonation arrester, and 2) all of the independent safety systems required to be installed when stable detonation arresters are used will function properly.

The major approval agencies in the United States and Canada - United States Coast Guard (USCG), Underwriters Laboratories (UL), Underwriters Laboratories of Canada (ULC) and Factory Mutual (FM) - all require that detonation arresters be tested to withstand unstable (overdriven) detonations.

 

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