Drain valve for water table

Instead of using the 1/4” drain plug for draining my SS water table AND for clamping my cutter ground to (which was a poor design at best) I decided to add a simple valve in. I bought a 3/8comp x 1/4 mpt brass valve and screwed it straight into the female drain fitting. The valve seal is brass on brass so no issues with a gasket over time. I put a toilet/faucet hose on it to direct water to a bucket. I will eventually set up a pneumatic drain/fill tank but this is my fix for easy draining and a much better way to ground my cutter.

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You should be grounding your cutter directly to the metal you are cutting for best results… There is a difference…

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My current table I put a regular faucet type valve on the water pan to drain it. It immediately filled up with plasma debris and plugged up. I couldn’t even close the valve. Right now I have a swamp cooler overflow pipe for a drain, I just pull the pipe out and let it go.

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I agree. I don’t understand using the drain plug as a tie point for the Work Clamp. First, on the inside of the pan, the drain bushing is isolated by a neoprene gasket. On the underside the fitting is isolated by teflon tape or some other ‘putty’ to seal the pipe thread on the fitting.

I simply clamp to the lip of the Water Table and haven’t had a problem. If you’re doing hot rolled stock or some other material that had some insulating surface (Anodized Aluminum to take a random example) then you need to grind down to bare metal and clamp on the work piece itself. Don’t forget, you’re trying to get 40-50Amps through this connection.

And, finally, I use a simple ball valve with a barb and hose on output for the drain. The first time it was filled with debris and didn’t drain, but I simply poked at the opening from above to disturb the sediment to get it to flow out. Now I drain it more often - mostly just to reduce loss of liquid due to evaporation.

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@Dicky I definitely am doing that when possible. Sometimes there’s just not enough material to make it feasible.

I put a bar sink drain in mine, it’s about 1.5", rubber connector to 1" drain hose that goes into a plastic container with ball valve… I use air to fill it up… I’ll see if I can find a pic… I always clamp to the metal… I have started jobs and forgot to, clamp just sitting in the water on the water table and wondered… Why is this cutting like shit… Ooops, then I remember…

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I found them… Just a simple bar sink drain, hasn’t clogged up yet… replaced that hose with a better one though, that one sucked…

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Do you get allot of the sediment down in your water container?

I havent checked in 8 months… it fills, it drains, it’s good… If it breaks, I’ll fix it… and I cut a lot of stuff! Lol, original slats…

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I like that sink drain. I wondered how the seals in a ball valve would hold up with that abrasive plasma sediment .

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8 months and counting, I’d say they are holding up pretty good!

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I put a piece of scotch brite under the slats and over the drain. acts as a filter and diffuses the water as it comes back out, no geysers

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I like your ‘refill’ method. Maybe this is common practice, but it’s the first I’ve seen it. It appeals to me in that it lends itself to automation (just need a pneumatic valve on your air inlet).

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Great idea!
One question though, what happens if you’re cutting over it?

Where did you get the tank?

@Dicky I love the tank design. It’s exactly what I was planning on fabbing up myself. The larger drain looks like a pretty solid improvement. I may do the same thing when I get to that point. @JaVelin great idea using scotch brite.

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Doesn’t seem to harm the scotch brite it’s well under water. If it melts a little I dont care but I haven’t. Noticed that. Thinking also theres not many times where the torch passes over that particular spot anyway.

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Leaving it in the water cuts way better than when you leave it on the floor next to the machnie :see_no_evil:
and yes I have done it more than once. 1/4" plate will not even pierce but it does a crappy etch job.

It’s ok, but it’s not fully automated… You have to vary the pressure as it fills… To much and you just must blow the plastic and have yourself a real mess… I almost did it last night, turned on the compressor, unplugged the plasma line, plugged in the tank line (I know get a splitter), and the valve was WIDE open!! I thought the tank was going to explode…

Also, the pvc ball valves are getting a little hard to turn, not enough for me to replace them yet, but… I imagine it would not matter brass or plastic, with no filter a bunch of junk is probably tearing up the valve… I like the scotch bright idea, gonna have to implement that! Probably should clean out the tank first… I havent done that in 8 months since I started, so probably due… I just keep adding water from the top…

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Dicky,

I would buy a cheap regulator (Harbor Freight has $5 regulators) dedicated to the tank always set low. May help to prevent this in the future. But now that you’ve done it once it’s probably a “mindset” event…LOL