High Speed Abort Gate for Dust Collection System

This component activates to divert the duct airflow out of the building for fire safety in case of an explosion. October 20, 2013

Our insurance loss control was out last week and we got a clean bill except for the new DC we are installing. He is saying we need a high speed abort gate on the return air. Anyone have one or know what they are all about? I searched google and it looks like a huge monster!

Forum Responses
(Dust Collection and Safety Equipment Forum)
From Curt Corum, forum technical advisor:
When required, they would be located on the return air duct from dust collector and prior to dust collector. In the event of a bag house explosion, diverts to outside instead of back into the building. Pyroguard has them from 4" diameter to 60" diameter.

From contributor D:
They are cost effective and are located on the return air duct after the dust collector to meet NFPA 64 requirements for fire. Usually these are tied to a spark detection system which we [Kraemer Tool] also supply to operate the abort gate if a spark is detected in the duct that is travelling towards the dust collector.