Galvanized Round End Cap
The cap that neatly closes the end of a round duct or the outlet of an unused fitting.
AirGreen codeAG-VC-01206
514 316-2973 · sales@airgreen.ca
Quick facts
The galvanized round end cap closes off the end of a round duct or an unused fitting outlet, such as a tee or wye kept for later. Available from 4 to 12 in, it replaces the cardboard-and-tape fixes still found in many basements.
A duct system closed where it should be
After a renovation, there is often a cut-off branch that no longer feeds anything, or an opening left for a future addition. Every poorly sealed opening sends heated or cooled air into a ceiling or wall, at the expense of the rooms being served. The cap closes the duct mechanically; tape is then only used to seal the joint.
Seven diameters
Available in 4, 5, 6, 7, 8, 10 and 12 in. Choose the nominal diameter of the duct or outlet to be closed.
Good practices
- Close off an abandoned branch as close as possible to the main duct, so you do not leave a dead section of duct.
- Screw the cap in place and seal the joint with aluminum tape or duct sealant.
- Before removing a forced-air branch, make sure the unit keeps enough outlets for its airflow.
- During work, a temporary cap keeps dust out of the ducts.
The cap simply comes off the day the branch needs to be connected.
Available from AirGreen in Greater Montréal
We adapt duct systems during renovations in Montréal, Laval, Longueuil, on the South Shore and on the North Shore. RBQ licence 5645-9605-01, subcategory 15.8 Ventilation. For availability or a quote, call us at 514 316-2973 or email sales@airgreen.ca with the diameter and quantity.
Closing what is no longer used, or not yet
An abandoned branch or a fitting waiting for a connection leaks heated air: the cap closes it for good.
- Closing an abandoned branch after a renovation
- Tee or wye outlet kept for a future connection
- End of a round trunk duct
- Keeping dust out of an open duct during work
7 sizes, one page
Each size has its own AirGreen code. Tap a row to select it.
| Dimensions | AirGreen code |
|---|---|
| 4 in | AG-VC-01201 |
| 5 in | AG-VC-01202 |
| 6 in | AG-VC-01203 |
| 7 in | AG-VC-01204 |
| 8 in | AG-VC-01205 |
| 10 in | AG-VC-01206 |
| 12 in | AG-VC-01207 |
Nominal diameter of the round duct to close.
Specifications
From the manufacturer’s documentation. A value the manufacturer does not publish is not listed.
What to know before installing
- Choose the cap with the same nominal diameter as the duct or outlet to close.
- Screw it on and seal the joint with foil tape or mastic.
- Before closing a forced-air branch, make sure the system keeps enough outlets for its airflow.
- Mark capped outlets on the plan.
You may also need
Galvanized Tee Fitting
Galvanized Wye Fitting
Galvanized Round Pipe – 60 in Length
Galvanized Side Take-Off
Cleats for Galvanized Duct (C and S)
Galvanized Oval Duct – 60 in Length
90° Oval-to-Round Elbow (Oval Duct)
45° Flat Oval Elbow (Oval Duct)Ventilation ductsSee all
Frequently asked questions
Why not just use tape?
Tape alone over an opening eventually gives way under air pressure. The cap closes it mechanically, and the tape only seals the joint.
Can I cap a branch that is no longer used?
Yes, close it near the trunk. First check that the equipment keeps enough outlets for its airflow.
Can the cap be removed?
Yes. Remove the screws and the tape to connect the branch later.
Can you modify my duct system?
Yes. We rebuild and adapt duct systems during renovations across Greater Montréal.
A duct system with no leaks or open ends
Tell us the size and the quantity: we confirm availability and send you a quote. Or let our technicians install it for you.
Specifications from the manufacturer’s documentation, checked on October 7, 2026.