Deflagration = Explosion propagating at subsonic velocity

Short Time Burning = Stabilized burning for specified time

Inline deflagration flame arresters designed to prevent transmission of a deflagration (explosion propagating at subsonic velocity). Inline deflagration flame arresters are fitted with two pipe connections, one on each side of the flame arrester.

Inline deflagration flame arrester approved for stabilized burning for specified time. For detection of a stabilized flame a PT100 temperature sensor mounted on the unprotected side is necessary!

When a stabilized flame is detected an action within 30 seconds (short time) has to be carried out which ensures a safe quenching of the flame. (E.g. inerting or stopping the gas flow)

 

Inline Deflagration Flame Arrester – Short Time Burning: Explanation

Deflagration = Explosion propagating at subsonic velocity

Short Time Burning = Stabilized burning for specified time

Inline deflagration flame arresters designed to prevent transmission of a deflagration (explosion propagating at subsonic velocity). Inline deflagration flame arresters are fitted with two pipe connections, one on each side of the flame arrester.

Ignited explosive gas mixture will propagate through the pipe in direction to e.g. storage tank. With pipe length flame speed increases. Up to a certain pipe length / pipe inside diameter ratio, the flame propagates at subsonic speed. Inline flame arrester approved for deflagration stops flame propagation at subsonic speed.

Inline deflagration flame arrester approved for stabilized burning for specified time is equipped with a PT100 temperature sensor mounted on the unprotected side. As soon temperature increase and stabilized flame is detected an action such as inerting or closing of a shut-off valve to block the vapor flow is necessary. This action should start within 30 seconds (short time burning) and extinguish the flame so that the system can operate safely. Inline deflagration flame arrester approved for short time burning are also approved for atmospheric deflagration.

Inline deflagration flame arresters has a lower pressure drop than detonation flame arresters.

However, consider when installing inline deflagration flame arrester that the distance from ignition source to inline deflagration flame arrester is limited.