Compressor draining

[Jim Becker]

My compressor is never, um....de-compressed. I do have an automatic drain system on it, however, to keep moisture from accumulating.

[johnny means]

I drain mine when I start seeing water at my end of the hose I keep tellin myself I should do better.

[Brian Penning]

Aren't most of those drain valves something like a 1/2" from the floor and pointed downwards?
I know on my old PC pancake and present Makita compressor it is.
How do you install the ADV?

[Byron Trantham]

+1, except that I bought mine at McMaster Carr. It was about 30% less than Graingers...

+2, except I got mine free from my brother-in-law! :-)

[Matt Day]

Aren't most of those drain valves something like a 1/2" from the floor and pointed downwards?
I know on my old PC pancake and present Makita compressor it is.
How do you install the ADV?

The stock petcock (drain) on my CH horizontal compressor is about 1.5" from the floor. I'm in the middle of installing my HF ADV, and the only thought was to put a 2x4 under both the front and wheels to raise the compressor and still allow water to drain. I though about hardpiping it out, but I figured the ADV needs to be at the lowest point. Any suggestions are appreciated.

[Peter Hanson]

Anyone have the part number for the HF ADV - can't seem to find it on their web site...

Thanks!

[David Hostetler]

The petcock on my HF compressor is 2" off the floor. (I measured it when I started thinking drain valves...).
FWIW, I still haven't drained mine from this weekend...

[Chip Lindley]

Those little "finger-getter" petcocks were installed in the most inconvenient place by Satan himself! Replace it with a 1/4" 90 degree nipple and a length of 1/4" pipe so a ADV can be threaded on. It is really worth the effort!

These are pricy from commercial sources but can be had verrrry reasonably if you hawk eBay for one. I installed a brand new Ingersoll-Rand ADV and Norgren regulator on my 60 gal. Quincy for cheap!

The I-R auto drain has a timer to set the blow duration in seconds, and interval from 1 to 60 minutes. Really Neat! That open exhaust port can be piped out through a wall to reduce noise AND water in the shop.

[Chris Tsutsui]

So is the purpose of draining water to prevent corrosion on the inside of these tanks? I wish more tanks were well coated... I know mine isn't.

I wonder why cathodic protection is never used in conjunction with these other drain methods for compressed air tanks...

Securing aluminum to the bottom of the tank can sacrificially protect a steel tank bottom (Galvanic). Basically the aluminum will sacrifice itself to protect the bare steel, but the aluminum has to be submerged in the condensed water (if there is any). You could insert the steel rod in a pipe that gets attached to the drain valve. Or fabricate a drain valve that has aluminum rod in it, or manufacturers could weld a bracket in the tank bottom that aluminum anodes could get bolted to.

Another idea is to use a non-evaporative fluid such as aliphatic alcohol on the bottom of the tank will prevent evaporation of the settled water. This fluid is lighter than water, floats on the top, and prevents the water from evaporating and causing surface rust.

BTW, there may be pitfalls in these ideas as I just shot these out there as food for thought.

Personally I like the idea of the auto-drain, though a sacrificial galvanic cp system could leave water in there and the tank will be protected.

[mickey cassiba]

Lot's of great ideas...but for me and my $90 compressor, opening my (self installed ) ball valve just works. I worked in maintenance for a while at DeVilbiss, before moving up the road to Porter Cable( all now divisions of Stanley/B&D). The bottom line there was not about making efficient, long lasting compressors...it was about making lots of bucks, quickly. I suspect some of the higher end labels(IR, and Quincy) have pretty much the same motivation. Besides, if the unit won't wear out, how are they gonna sell you another in a few years? Capitalism 101.

[mickey cassiba]

The stock petcock (drain) on my CH horizontal compressor is about 1.5" from the floor. I'm in the middle of installing my HF ADV, and the only thought was to put a 2x4 under both the front and wheels to raise the compressor and still allow water to drain. I though about hardpiping it out, but I figured the ADV needs to be at the lowest point. Any suggestions are appreciated.

If your pump is an oil lubricated one, you need to maintain the pump alignment...if it's an oil less unit you can run it upside down if you wish

[Mike Harrison]

Mine has been "on" for ten years in this shop. I drain it once a week during late spring, summer, and early fall. Change the oil at Christmas time. I installed a street el, piece of 1/4" pipe, and a ball valve for draining.

[Jim Foster]

The pressurized tank for compressors will be/should be designed for infinite life, otherwise it's a bomb waiting to go off. Since most tanks are made of steel, infinite life is reasonably straight forward to design for. Airplanes have weight to contend with and are often made of aluminum pieces which have finite load cycles regardless of maximum stress levels seen in service. There may be other negative usage issues associated to cycling the pressure, but fatigue should not be one of them. It might be that the biggest danger point is corrosion on the welds from minerals/chemicals in the water or air.

[Tony Zaffuto]

I open the drain and let it open until the next I use the compressor.

[Chris Parks]

Mine has been "on" for ten years in this shop. I drain it once a week during late spring, summer, and early fall. Change the oil at Christmas time. I installed a street el, piece of 1/4" pipe, and a ball valve for draining.

This, just make the pipe larger and the water settles in the pipe not in the tank and the tank should last longer. The bigger the pipe the less it needs draining if the user forgets. Me, I like ADV's, they save me having to access the compressor which is outside the building and a pain to get to.