Self-Cleaning Blast GateQuestion

[Steve Eure]

I replaced all my plastic blast gates with the self-cleaning aluminum gates. Now whenever they are closed, I can hear and feel air being sucked up though the bottom. Is this normal? Is it enough air loss to be a problem.
I have a 2 HP HF collector with an Oneida SSD and am impressed with this setup over my other configuration that I had. The air suction on the closed blast gates baffles me though.
Just wondering if this will be a problem?

[Paul F Franklin]

A little leakage is common. But make sure you have them oriented correctly. The knob that tightens against the gate should be on the tool side of the gate. There is less leakage that way.

[Jim Dwight]

I have the HF unassembled waiting on me to have time to combine it with a super dust deputy, barrel, poke a hole in the exterior wall for the exhaust, etc.. I finally got a propane line run today for the grill so if I can figure out the connections to the grill and get that done that project is over and maybe the DC will be next.

But I am debating size of the ducts and the material. If you don't mine saying, what size and material did you use? Are you satisfied with the performance (your OP seems to indicate you are).

[Matthew Curtis]

A little leakage is common. But make sure you have them oriented correctly. The knob that tightens against the gate should be on the tool side of the gate. There is less leakage that way.

I just had an "ah ha" moment. Thanks Paul

[Steve Eure]

Jim, I am using 6" HVAC pipe on the main run from my lathe and sander, but just 4" pvc from everything else. I ran 4" because of all the wye's I had to install and 6" wye's were more than my budget could handle. The 4" seems to work ok, although some will argue with that. On a short run, there is no problem. I then had to reduce sown to the 4" that fed into the dc.

[Steve Eure]

Yeah, thanks Paul. Who would have thunk it? I went into the shop and checked the orientation of the gates and 6 of my 9 gates were backwards. Changed them around and the leakage stopped.
There is no indication on the blast gates to show the direction of flow. I'm glad I asked here on the Creek. Thanks again Paul!

[Larry Frank]

I I tried one metal gate and do not care for them. I made my own for both 6" and 4" . They seal tight and self cleaning and less expensive.

[David Kumm]

On most gates you can just change the screw so it pushes the steel towards the airflow. No need to switch the actual unit. On larger systems with larger mains the leakage is actually a good thing as it adds some air to the mains which are typically much larger than the ports. Dave