Do all self cleaning blast gates leak?

[Steve Kozusko]

Was thinking about the design of blast gates while putting together my DC system. With self cleaning gates one end side of the track is open to allow the dust to be pushed out of the track by the door. What happens when the gate is open? Wouldn't there still be the opening at the end of the gate? When closed the set screw and suction will push/pull the plate and seal off the pipe but when open it seems inevitable? Thoughts?

[Jim Becker]

It depends on the design of the gate, but it's not uncommon for some leakage at gates even when they are not self-cleaning! I don't have any self-cleaning gates and never felt a need for them to be "cleaned', honestly.

[Frank Pratt]

Any commercially available gates I've seen all leak some, but it's an insignificant amount. I use self cleaning gates from Lee Valley and when they're all closed you can hear them leaking, but there's very little air passing through the blower

[Mike Henderson]

Mine leak a bit when they're open. But when they're closed, the gate closes the opening that lets the swarf fall out of the groove. I suppose even then, they leak a small amount but it would be miniscule.

Mike

[Steve Kozusko]

Thanks. I ordered the Lee Valley ones. Thinking the extra piece in the gate would help in the leakage. Probably doesn't matter much but had to buy something. Thanks for the replies..

[Jon Snider]

Turning this question somewhat around. I never had any SC gates for first shop. I’ve read about them for new shop but not really sure they’re necessary. ??

[Mike Henderson]

Turning this question somewhat around. I never had any SC gates for first shop. I’ve read about them for new shop but not really sure they’re necessary. ??

Depends on whether the gates you have get clogged up. My originals would get impacted with swarf and then I couldn't close them all the way. The self cleaning have one or two holes at the end so that when you close the gate, the swarf is pushed out. Or maybe because of the opening, the swarf never accumulates in the first place (it is sucked into the pipe by air coming in from the self cleaning opening).

Anyway, my self cleaning work. No more jammed gates (meaning unable to close them all the way).

Mike

[Jamming may also be avoided by having the gate mounted so that you push the gate up to close. But if you push the gate down or to the side, the groove the gate rides in can get loaded with swarf.]

[Pete Staehling]

Depends on whether the gates you have get clogged up. My originals would get impacted with swarf and then I couldn't close them all the way. The self cleaning have one or two holes at the end so that when you close the gate, the swarf is pushed out. Or maybe because of the opening, the swarf never accumulates in the first place (it is sucked into the pipe by air coming in from the self cleaning opening).

Anyway, my self cleaning work. No more jammed gates (meaning unable to close them all the way).

Mike

[Jamming may also be avoided by having the gate mounted so that you push the gate up to close. But if you push the gate down or to the side, the groove the gate rides in can get loaded with swarf.]

FWIW, the Harbor Freight gates had that problem and were loose enough that the gate fell down and open if mounted so that you push it up to close. The could be modified to solve that, but I ultimately gave up on them in favor of a shop built manifold with built in gates.

[Bill Jobe]

I used to keep koi and tried a valve similar to blast gates to close the system just past the pump. They would eventually clog up and not fully close.
To fix the problem I mounted the valve with the handle side down. That worked with water, but it's not really a good idea for ponds. I switched to ball valves.
Don't know if they are of any use in DC setups.
If the slot where the gate closes is up, there is a better chance of it not filling up with dust.

[Norman Pirollo]

Don't have the self-cleaning blast gates but what I did was re-orient my horizonal or angled blast gate to have the enclosed section face upwards. Seems like they close better since, as dust doesn't impact uphill. The straight vertical gates, nothing much to do except clean them out every so often. Fashioned a small device to be able to fish dust out of the compartment though.

Norman

[Bill Space]

My question would be "what if they do leak a little"?

The leakage must be very small compared to the total flow pulled by the dust collector.

Personally, I would not worry about it.

Even if they all leak while closed, just a little, it probably is a non issue. Just my take on it.

Bill

[Frank Pratt]

Blast gate leakage is like tempest in a thimble.

[Bill Jobe]

Blast gate leakage is like tempest in a thimble.

That depends on the level of effeciency of the DC.
If the system is borderline underpowered it could make a difference. But if the DC system is overbuilt I could see leaky valves as not being a problem.
Like they say in the drag racing community, "nothing succeeds like cubic dollars".