Air compressor - bottom drain valve - advice re mods

[Howard Rosenberg]

Has anyone here changed their compressor's original bottom drain valve to either a ball valve or a 1/4-turn valve?

If so, any advice?

Mine's a 25-gallon Porter Cable. Crouching down to wrestle with that tiny little drain valve is really getting old (just ask my knees.)

And, because this thing will be impossible to lift onto my bench, any idea how to ID the diameter and thread?

[Jim Becker]

Yes...I did that many years ago to my IR compressor. If I recall, it was all 1/4" NPT and very easy to reconfigure after removing the OEM stopcock from the bottom of the tank. The piping I used after a 90º elbow extends out to the perimeter of the tank and there's a ball valve there. At the present time, I just have a hose connected to that that passed through the wall of my temporary gara-shop and I exhaust moisture manually on a regular basis. Once I'm back in a dedicated building, I'm planning on getting another auto drain to replace the one that died after many years at the old shop.

[Tom M King]

I always change them to a ball valve. Some, I use a street elbow and nipple to extend it out where it's easy to get to. The only one I haven't changed is on the little aluminum tanked California Air that has a decent valve to start with.

[Howard Rosenberg]

Thanks Jim.

Do you know how much a difference it makes if the ball valve is rated for plumbing vs gas? HD has both and they're both rated to 175PSI. And if it's not too much trouble, is it possible to post a pic of your current setup. Many thanks.

Thanks Tom!

[Tom M King]

I just bought metal ones made in the USA, and never noticed what they were originally intended for. They have all been a good many years back, so meeting those requirements may be more difficult these days. Not one has ever leaked, nor needed to be replaced.

[Malcolm McLeod]

Has anyone here changed their compressor's original bottom drain valve to either a ball valve or a 1/4-turn valve?

If so, any advice?

Mine's a 25-gallon Porter Cable. Crouching down to wrestle with that tiny little drain valve is really getting old (just ask my knees.)

And, because this thing will be impossible to lift onto my bench, any idea how to ID the diameter and thread?

Agree, that 90% of home-shop-sized compressors in USA will have 1/4" NPTF on the drain port. The 1/4 turn ball valve is simple and quick, if you remember to use it!!

If you want automated drains there are generally 2 types: electrically-operated (timed) and float-operated.

In an industrial environment w/ 24/7 operation, the electrically-operated style typically last 1-2 years - even if it has I-R on it. In a home shop I'd expect 5-8 years if you leave your air system powered 24/7, but only 'in-use' 5-10% of that time. Or, you might get 10-15 yrs, if you power down the compressor AND auto-drain when not in-use. Unless you power the drain down, they will continuously bleed some air, even if there is no water. I will not spec these for our company use anymore. ...Buy early, buy often.

Float-operated are much more reliable, longer lasting, use no power, and don't bleed air at all when there is no water. They are typically the largest option and might mean raising the typical small shop compressor 4-6" off the floor. I think there are some cheap units available (think Amazon, $30-$40?), but quality of course costs more.

No matter the drain option, be aware of the system pressure (use caution/watch you eyes) and where you drain the water; it will be rusty. You can drain it on the floor, or (manually) into a bucket if there is room under the (new) valve. It will stain the floor. - - Maybe use some cheap drip irrigation hose and route to a floor drain, sump, or outside in a discrete spot that looks good in orange?

ETA - I've seen some installations where the user threads a sintered bonze filter into the drain valve; it keeps rusty water from blinding you or painting the entire area, but the trade off is that the filter slowly plugs with the larger rust particles.

[Howard Rosenberg]

Thanks Malcom. My setup is nowhere is as sophisticated as the options you describe! I'm just trying to get as much life out of my knee as long as possible!

[Jerome Stanek]

I have an auto drain plus the ball valve hated the wing nut style that it came with

[Malcolm McLeod]

Thanks Malcom. My setup is nowhere is as sophisticated as the options you describe! I'm just trying to get as much life out of my knee as long as possible!

There really is nothing sophisticated about receiver drains. Virtually every industry uses compressed or instrument air in some form or fashion, so there are dozens of options for drains. Here is just one manufacturer. See the "Standard Timer Controlled Drain" , the "Egg Drain", and/or the "Mechanical No Loss Drain". They are all about the same installation effort as a manual valve and REALLY easy on the knees.

[Warren Lake]

home depot parts, put it where every you want. The odd time I left it a tiny bit open and it did auto drain but normally just turn it drain close it. 5 HP 2 stage 80 gallon tank, Plan to replace it with two of them.

DVC00141A.jpg

[Jim Becker]

Thanks Jim.

Do you know how much a difference it makes if the ball valve is rated for plumbing vs gas? HD has both and they're both rated to 175PSI. And if it's not too much trouble, is it possible to post a pic of your current setup. Many thanks.

Thanks Tom!

At the time I did it, I have no idea which "version" of the ball valve I purchased from the 'borg. Unfortunately, I have a lot of stuff piled in front of my compressor right now in the temporary gara-shop, so getting a photo would be darn difficult. Please trust me, however...this is a really easy modification. Probably easier on your smaller compressor than it was on my 60 gallon unit since you theoretically can tip it to gain easier access to the OEM stopcock.

[Bill Dufour]

I used an elbow and pex out to the valve. The tank pressure will push water up and out well over 100 feet in height so I recommend put the valve up at waist height even if the drain pipe then drops down to floor level. Your back will thank me.
Bill D

[Howard Rosenberg]

Thanks Jim. appreciate it!

Thanks everybody.

[Wayne Cannon]

FWIW, my auto-drain empties into a shallow Dollar Tree aluminum roasting pan under the compressor. It's high enough to contain any splatter, and the water evaporates faster than it accumulates.

[Alan Lightstone]

My auto-drain valve on my California Air Tools compressor drains into a pickle jar. Never had to empty it. The water must evaporate.