Model 0540V Large Body Static Curtain Fire Damper is UL authorised to be used exactly where setting up codes have to have the safety of HVAC ductwork penetrations in vertical fireplace separations (walls or partitions) which have a fireplace resistant ranking of 4 several hours or a lot less. The https://myleshyocp.theblogfairy.com/36095434/heavy-duty-stainless-steel-damper-manufacturers-an-overview