Vacuum ball valves

[paco]

Hey Botters!

I need help finding recommend ball valves for vacuum usage. I'm on my second set (2 X 4 valves) in a few months because they jam (wont turn no more) from being use dry and in dusty environment. I still don't use a bleeder board (because I can't get any so far on this part of the world) but even with that, the ball valves would still be run dry and still get some dust.

I'm at the point where I'm considering brass ball valves to overcome this problem but 2" brass ball valves aren't cheap.

If you have been using yours for a fair moment (a year or more) and still are happy with them (read easy to turn), let me know or post information regrading brand and sources.

Thanks in advance!

[srwtlc]

Hey Paco,

I don't have any ball valves myself (yet), but could you use some kind of dry lube? I've got some " Gunk Liquid Wrench" with PTFE that is supposed to not collect dust residue.

Just a thought.

[ed_lang]

Paco,

I have used two different types on my system. The ones I like best come from the DIY home store Lowes and they have a "union" on one end. I can unscrew the union and take the top (or bottom) off and get right to the ball. I could lubricate clean or whatever to it. The tighter you screw the union ring down the harder it is to turn the valve. I also see the one piece ball valves that have no way to get to the ball when the valve is installed.

Here is a link to the ones I use.

http://tinyurl.com/2cuzof

[paco]

I've thinking about a concept...


3449


3450

made of acrylic. Knife/guillotine type. The acrylic body parts would be glued/weld with a tiny/no clearance. Still need to figure the fitting part but I'm mostly concern regarding leakage...

The idea is not exactly saving or cheap valve but one that wouldn't get stuck. Simple design are often the best one...

What are your thoughts on this?

[ljdm]

Machine a round groove for an "O" ring, grease the ring. It would seal it, and still move fairly easy. Either rubber(more friction), or a Teflon type - similiar to a slip joint washer on a drain pipe. My 2 cents.

[paco]

Here's an update and a cross view half way open...


3451

[wberminio]

Have you tried this wrench? It really works.
I made mine out of PVC pipe.


www.talkshopbot.com/forum/messages/29/7575.html (http://www.talkshopbot.com/forum/messages/29/7575.html)

Erminio

[beacon14]

Paco,

I have the one-piece PVC type valves and only some of them are sticking - the ones that get the most dust on them during cutting and in particular the ones I turned a few times without vacuuming the dust off first. I've had some success with shooting some spray lithium grease into the area where the ball and housing meet. Now that I am cutting more full sheets I find I have to turn the valves less often but I always make a point (too late) to clean the valves off before turning them. Vacuuming is best as blowing with compressed air will just blow the dust further into the joint.

Your gates work with the same principle as my dust collection blast gates. Either full on or full off with no where for dust to collect in either position. I used All-Star gasketing on the inside faces of the housing figuring when the dust collector (in your case the vacuum) is on it will pull the gate tight against the gasket to seal itself off.

Ideally I'd like to get a solenoid system so I could just flip a switch...

[gpari]

Paco, I have the ones that were supplied with the vacuum from shopbot. Just the plain solvent weld plastic ones found at any big box home supply store. I have been running them for about 18 months. The first year, I didn't have a pre filter on the bypass valve. Consequently, that valve saw plenty of dust and chips, and I had to clean the vacuum filter weekly. Now I have a big fram automotive filter on the bypass valve, so it sees virtually no dust. But, they are all still working just as good as the day they were installed. They don't leak when closed, and are easy to operate.

Guess I'm just lucky.

Gabe

[borg_industries]

You have two options. Try spraying your ball valves with a silicone spray and work it in. The spray will dry and not collect as much dust as an oil will. Some sprays will attract dust from the positive charge ions in the spray. Just keep this in mind. Second, Jandy valve has a Never-Lube Ball valve. They are used for swimming pools/ hot tubs/ watter falls. Search the net for the best price. Some suppliers really jack up the price on pool equipment so expect to spend some time looking.

[Gary Campbell]

David..
I sent Paco a few websites that have PVC Knife valves. I dont have the R&D time at the moment, so I am hoping he will test them in the dust. Their OEM application is for pond water, so dirt should be OK. If you get the right ones, they have replacable seals. If they work, I will be adapting them to an air cylinder for either air or electric solenoid switching. This is the next Bot project after I get the rest of the E-Chain and center supt. leg project completed.

[paco]

R&D days at USINUM (http://www.cooptel.qc.ca/~usinum/).

About this idea of an all acrylic gate/knife/guillotine valve, this is what I came with so far (http://youtube.com/watch?v=7Aek4c-DsXc). It perform very well with minimal to no leakage and couldn't be more easy to use.

More later... I'm out to the plumbing supply... I'll have a look at those off-the-shelf knife valve that Gary refer to. I'll post the details on my Blog (http://pacosarea.blogspot.com/) sooner or later.

[harold_weber]

Not clear how to adapt these to fit PVC pipe, but they are claimed to be "self cleaning"...

http://www.leevalley.com/wood/page.aspx?c=2&p=51506&cat=1,42401&ap=1 (http://www.leevalley.com/wood/page.aspx?c=2&p=51506&cat=1%2C42401&ap=1)

[Gary Campbell]

Guys...
Here are the valves I am trying to get Paco to test...

3452
$15 ea in the 2" version..easy to use, lots of leverage, and you can replace the seals if needed.
Gary

[paco]

Harold,

I tend to think those would leak too much... at least the ones I've checked were too lose. "My" concept is similar though but have very minimal clearance.

Gary,

yesterday, at the plumbing supply, I had those in my hand and I decide they were not that interesting. They are a bit stiff even though the movement to actuate is more easy than a PVC ball valve. They use rubber seal with a thick lubricant; that might be a problem with dust. Both the lubricant and the rubber seal. The fact that they can be serviced is pretty much non sense in the case of a such system as we use as once glued, one wouldn't be able to take the valve apart unless cutting something. Did I mention those cost me $30.00 locally?...

More later on "my" idea... yeah, I didn't re-invented anything...

[Gary Campbell]

Paco..
Thanks for the heads up. am not able to get hands on here. Internet only.
GC

[paco]

Problem solved. Information is online on my Blog (http://pacosarea.blogspot.com/2007/12/all-acrylic-gate-valve-for-vacuum-hold.html).

Let me know what you think!

[Brady Watson]

Looks great Paco! Thanks for the link.

-B