Water in compressor tank

Determined

Well-known Member
Reading the post about compressor tank explosion got me to thinking, as rust caused by not draining the tank is probably a contributing cause of failure in many cases.

For years I had a 60 gal upright compressor sitting on the shop floor.
Even if you drained the water off it daily you would always get at least a half of a cup out of it.

Replaced it with a 80 gal horizontal compressor 5 years ago, not wanting the noise in the shop I installed it in the barn loft next to the shop.

I have a line with a tap on the end connected to the factory drain port that hangs on the shop wall so I can easily drain the tank without having to go upstairs.

Even if I leave it for a week at best I might get a tablespoon of water out of it.

So is there a difference between vertical versus horizontal tanks?
Different compressor head design?
Is it drier up in the loft compared to the shop floor?
Barn is not heated, attached shop heated with a wood stove when needed.

Any thoughts or similar experience.
 
Well, a vertical tank will drain all of the water out better.
Heat rises so maybe having the intake up high in a building utilizes the some what dryer air to be used?
Especially if you only turn it on during the day.
 
Is the loft a warmer area?

If so, there is less water vapor condensing inside the tank. Condensation needs a cool surface to collect on. That's one purpose of the tank, to catch the water vapor before it goes out into the line.

You'll probably be seeing more water in the lines now than before.
 
I have both 60 and 80 gal vertical compressors. Both are in unheated buildings.

Both have timer controlled electrical tank drains. Because the timers can be set no less frequently than every hour, I leave both unplugged and simply plug them in momentarily when I walk buy to drain the tanks. Probably do this a couple of times each week, less frequently in the winter.

The exhaust of each tank drain is routed outside with clear tubing.

I never get more than drops/mist from either even if it has been 2 or 3 weeks when I cycle the timers.

Dean
 
You need ti look at surface area. A horizonal tank has a long flat area that water can gather. While a vertical tanks area is much smaller.

Cold air meeting hot (or vs versa) is where most watsr comes from.

Before you start your compressor. Open the drain valve and let the compressor run about five minutes to warm up and start pumping warm air into the tank before you close the valve. Bet you will get a lot less water at the end of the day. An ole car painter taught me the trick.

I installed a full flow ball valve to my drain and leave it open when I am done and close it after I start the compressor to warm up for the next round of use.
 
(quoted from post at 13:07:57 09/05/18)
Both have timer controlled electrical tank drains. Because the timers can be set no less frequently than every hour, I leave both unplugged and simply plug them in momentarily when I walk buy to drain the tanks. Probably do this a couple of times each week, less frequently in the winter.

Dean

Why not set the timers to drain twice a week?
 
(quoted from post at 09:59:13 09/05/18)
(quoted from post at 13:07:57 09/05/18)
Both have timer controlled electrical tank drains. [color=blue:63bf4bfe11][b:63bf4bfe11]Because the timers can be set no less frequently than every hour[/b:63bf4bfe11][/color:63bf4bfe11], I leave both unplugged and simply plug them in momentarily when I walk buy to drain the tanks. Probably do this a couple of times each week, less frequently in the winter.

Dean

Why not set the timers to drain twice a week?
 
I don't know all the in's and out's of this and am only guessing, but I would hazard to say the reason you got more water from the vertical tank is because water drains better through a vertical pipe than a horizontal one.

There also might be a difference in tank thickness, which would affect how efficiently the ambient air temp could condense the moisture inside each tank.

As for location, the shop is an active area with air flow and lots of moisture from breath. Every time people and animals exhale, their breath includes airborne moisture vapor.

Is there hay in the loft? If so, dry hay could act as a wick, pulling much of the water vapor from the air before it reaches the compressor.

Again, just guessing here.
 
Thanks for reminding me. Been a while since I drained mine (60 gal. vertical). Got maybe 1/4 cup. Ran the unit for a few mins. with the drain open, and will do again then button it up.
 
I would if I could, 007, but the timers can be set no less frequently than every hour.

These compressors are in non commercial farm shops and I don't want them popping off every hour.

Dean
 
(quoted from post at 15:32:59 09/05/18) I would if I could, 007, but the timers can be set no less frequently than every hour.

These compressors are in non commercial farm shops and I don't want them popping off every hour.

Dean

Oops, I had a brain fart and was thinking the timers could not be set at anything less than an hour, therefor you should be able to set at say anything more than an hour apart.
 
If the air in your loft heats up during the
day time that means that the humidity level
(grains of moisture/cubic ft of dry air) is
going down. Atmospheric air is a mixture
of dry air and water vapor. Heated air
expands rapidly (more cubic ft of air/lb)
but water already in vapor phase does not).
Dryer air going into the compressor means
less condensate in the tank. I have a 60
gallon vertical tank with an auto drain
valve at the bottom. Has a float valve
that opens the drain on water level rise.
Works good but needs to be cleaned out
every few years.
 
Draining the tank will only help a little. Even if you drain the tank hourly there will be a certain amount of moisture lining the inside. I have a compressor which had a long pipe attached to the compressor with a valve on the end. I set the valve to drain slightly 24/7 so it almost never did have water accumulate in the tank. Still the tank rusted out. What ever the inside of a tank is coated with when it breaks down you are going to loose the tank. I have a portable Campbell Compressor I bought new and from day one a sea of rust has come out of it when drained. I don't think they coated the inside of the tank with anything. If I had the time I would put an inspection camera in the tank to see.

Speaking of draining the tank a number of years ago I was hired to do some work for a homeowner which was doing a lot of the work himself and just had me do the things he couldn't. I watched him for a week at the end of the day he would take his little compressor and put a coupler on it letting the pressure down to 0. At the end of the week I got the nerve to ask him why he did that and he said the instructions said to drain the tank daily. He was flabbergasted when I told him what the instructions meant. When it was drained correctly I think the tank was more than half full of water.
 
I have a 60 gallon vertical. I like the idea of a vertical for several reasons. I left mine sitting on the bottom section of the shipping crate to get a little
space below to access the drain valve. Then one day I just plumbed it out front where it's easy to access.

My twin cylinder conventional oil lubricated compressor is several 10's of years old and "burns oil", not a lot but enough to find oil in the water drained
out. I like that idea since oil floats, as I drain the tank when I get the urge, the oil coats the tank and helps to prevent rusting through problems........I
would speculate.
 
Lots of interesting thoughts, still not sure exactly why the difference.
The compressor is on 24/7 year round no hay in the loft and no noticeable change in the amount of water any time of the year.

Not complaining as it works great, just curious as I fought with water separators and dryers for 25 years with the vertical tank and still would have moisture in the lines, with the horizontal tank in the loft it has been 5 years and the air it is putting out is dry enough that I can paint a whole vehicle without hardly a drop accumulating in the water separator.
 

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