Compressors - drain every day or leave pressured?

Page 1 of 4  
OK, I finally figured out my compressor purchase and went with the Campbell Hausfield 60 gal upright - Lowes was even nice enough to part with it for $399 (gloat?)
The manual says that the tank should be drained daily. I'm wondering what people usually do with their large compressors... do you drain the tank every day, or just leave it pumped up so it's ready when you need it?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I installed a ball valve to replace the t-screw valve, 1/4 turn to full open. I let the valve leak just enough than I can hear it leak if all is quiet in the shop, this will keep the water drained. Because it takes less than 5 minutes for mine to go from empty to full when not in use I switch the compress of from auto to off. It takes about 3 days to fully drain all pressure.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I see no justification to subject the tank unnecessarily through inflation/deflation cycles. I'm reasonably certain that by 'draining' they mean the water from the bottom of the tank. Always a good habit. Buy a fitting which will allow you to attach a swaged line (think brake line from the auto parts store) and run it up along the side to the top of the tank where it is easily accessible. Install a ball valve (as per Leon) up there. If you want to get fancy, attach a small swan neck to the ball-valve so you can conveniently catch the water as it comes out.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:
I see no justification to subject the tank unnecessarily through inflation/deflation cycles. I'm reasonably certain that by 'draining' they mean the water from the bottom of the tank. Always a good habit. Buy a fitting which will allow you to attach a swaged line (think brake line from the auto parts store) and run it up along the side to the top of the tank where it is easily accessible. Install a ball valve (as per Leon) up there. If you want to get fancy, attach a small swan neck to the ball-valve so you can conveniently catch the water as it comes out.
I have kicked around the idea of making the valve a bit more accessible but I think you are going to have to have a high volume release to persuade water to go up a line and out. If you simply let the air trickle the water is probably not going to be completely drained once the bottom of the tank is empty, I suspect that the vertical line would retain water.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

The air pressure will push any water up the line at tank-pressure until all the water is blown out. . I kept a 10 HP Webster drained like that for 20 years. The drain *is* at the bottom of the tank, the valve isn't. If you use an automotive brake line, it will clear all the water out. The vertical line will blow itself clear when you open the valve.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Air pressure on my compressor is never fully released unless we are doing repairs or upgrades, etc.
We do, however have a ball valve and tube at the bottom of the compressor and at a few low points on the lines to remove moisture as well as a large FRL at any point where a tool is being run. We drain the water daily via a 10 second opening of the valve, etc.
When we used to have super high volume needs (previous business) we set up an automatic timer that vented the valve at the bottom of the tank every hour for 2 seconds. We used to drain out a few gallons of water a day on the big compressors.
Folks in humid areas have highly efficient air dryers and possibly these purge systems to keep water out of air lines, etc. ...Especially medical and food grade systems.
But if you are talking air only? They must have a reason to do it, but I can't figure out what it is... I'd think pressurizing and depressurizing the system daily would cause unnecessary fluctuations and possibly damage long term - like bending a piece of metal back and forth slightly over and over again... Eventually, it fails / breaks.
Regards, Joe Agro, Jr. (800) 871-5022 01.908.542.0244 Automatic / Pneumatic Drills: http://www.AutoDrill.com Multiple Spindle Drills: http://www.Multi-Drill.com Flagship Site: http://www.Drill-N-Tap.com
V8013-R
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Mike wrote:

Pressure's not going to bother it, condensation however will rust it.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Rust is considerately reduced by the fact compressors are oil lubricated, so there is typically a water/oil mix in the tank. I used to worry about it, but my Craftsman compressor, which I inherited from my late FIL, never gave me an bit of trouble. When I sold it cuz of moving, it still worked great despite being almost 30 yrs old.
nb
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Yes, that is true on a oil lubricated compressor that has oil leaking past the piston rings but a new compressor that is not leaking oil past the rings will rust prematurely if you do not drain the tank often in a humid environment.
With that in mind also not all compressor oil lubricated. I have has an old inherited 80 gal oiled compressor developed pin holes in the tank because of interior rust.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Any oil lubed compressor will have some oil migration past the rings. It's almost impossible, or at least economically prohibitive, to attempt to reduce it in typical air tool grade equipment.

An example is SCUBA tank compressors, which are lubricated with a non-toxic soap solution and insanely expensive.

Nowhere did I state rust was entirely eliminated. I said it was reduced. Pay attention, please.
nb
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I probably don't drain the moisture often enough. My tank remains pressurized most of the time. My theory is I always have air available, and I'm not running the machine needlessly.
It is a good idea to drain the moisture out fairly often because moisture can cause problems. Small problems include getting moisture into paint and tools. Big problems include rusting out the bottom of the tank around the drain valve. The tanks are pretty much un- repairable so then you buy a compressor (or part out a similar one).
RonB
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Yeah and each compression stroke will have at least "1" atom of Ceasar's last breath. Compressors unlike automotive engines depend on the crank shaft and rod splashing in the oil to lubricate the bearings and cylinder walls. Automotive engines which are more likely to leak oil past the oil rings have an oil pump forcing the oil to all of those areas. through journals, crank shaft bearings, rod bearings and the connecting rods. Additionally, unless the rings in a compressor pump are leaking badly the higher compression in the cylinder area will help to prevent migration of oil past the rings into the cylinder, head, and eventuallly the tank. There has to be considerable loss of compression and blow-by past the rings above the piston before migration will happen. The amount that does migrate in a properly maintained and well running compressor is immeasurable. If you see oil coming out of your condensation drain you have ring problems. IF the amount of oil that you think that gets into the tank of a compressor is enough to prevent rust I suggest you get your compressor repaired. My "new" compressor is 14 years old and has never been low on oil although I am beginning to see a bit of rust come out with the draining water if it sets too long with out being drained. Occasionally I inadvertently bump the drain ball valve and close it. While a compressor will operate with leaking rings, like a gasilone engine that burns oil, it does not run as effeciently as it could be. You should not be depending ona a compressor pump that is in need of repair to protect your tank from rust, especially considering the many "gallons" of water that goes through the tank.

A more simple example and one that more closely meets the description of the type compressor in this discussion is the "cheap" oilless direct drive compressor.

No where did I state that you said that the rust would be eliminated. I was merely trying to pointing out that if you are depending on leaking piston rings to keep your tank from rusting you have more to worry about than a little rust in the tank.
So uh, practice what you preach.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I can see this is another pointless discussion. Have a nice day.
nb
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Amazing how many of those you seem to get into.
--
LRod

Looking back through the Bush years for his Positive Accomplishments is, for me,
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

I am certainly glad I did not have to paint you a picture. It has bee a darn good day.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Yes. You've made it quite clear. You don't know how to measure.
nb
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I used to work in a machine shop and I finally cracked the pet cock at the bottom of the tank so little that I had to use a plastic cup with water in it to get one or two bubbles every few seconds and just let it run like that M-F turned the compresser off Friday at 5 and resarted it on Monday at 7.
YMMV, Rich
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Mike wrote: ...

They mean for moisture as others noted...
I know what they say but...
The 80(?) gal compressor here is 40+ yr old and has been left pressurized/on 24/7 and hasn't been drained but a time or two in its lifetime (and would add a "maybe" to that estimate).
It's reasonably dry here but not desert; I never see evidence of a great deal of moisture in the air. Don't use much volume which probably makes a difference; if it were in continuous use would probably be more need...daily surely seems excessively a-r to me unless a large volume is going through the compressor daily and/or it is very high RH area...
just to toss in $0.02, etc., ... :)
--


Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Have you ever consider the need to internally inspect the pressure vessel?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Mike wrote:

Nope...
--
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.