Why does a volume damper leak when it is bolted metal-to-metal into a sleeve?
2nd YearDampers / SealingGREEN · Standard Correction
Metal-to-metal damper frames can leak around the perimeter. Back it off, clean the faces, add the approved gasket/seal detail, re-tighten evenly, and retest.
A damper frame bolted into a sleeve without gasket or seal can leak around the entire perimeter even if the fasteners are tight.
Find the leak path, unbolt only as allowed, clean both faces, install the approved gasket/sealant detail continuously around the frame, tighten evenly, and retest under fan pressure.
Field checklist
Confirm the leak is around the damper-to-sleeve frame, not the blade or downstream joint.
Check whether gasket tape/sealant was omitted or broken.
Clean metal faces before sealing.
Install continuous approved gasket/seal detail with no gaps at corners.
Tighten evenly and retest.
Ask Foreman
The volume damper frame at [location] is leaking around the sleeve. I checked the perimeter and it appears metal-to-metal. Do you want it backed off and gasketed/sealed per detail?
Use this as training guidance. The foreman, approved drawings, project specs, manufacturer installation instructions, employer safety policy, and AHJ/code requirements always control the final answer.