Compressors - drain every day or leave pressured?

[Leon]

"notbob" wrote in message news: [e-mail]...

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.

[notbob]

I can see this is another pointless discussion. Have a nice day.

nb

[clare]

Both. Leave the tank pressurized and just blow off the moisture from the drain daily (if it is used).

[LRod]

Amazing how many of those you seem to get into.

[Leon]

I am certainly glad I did not have to paint you a picture. It has bee a darn good day.

[notbob]

Yes. You've made it quite clear. You don't know how to measure.

nb

[me]

[LD]

Looking over their shoulders as they run, or just low to the ground hauling? :o)

[Leon]

Ahh an unexpected bonus that a comes with purchasing quality equipment.

[Steve Turner]

I've had an upright Sanborn (similar to your C-H) for the past 20 years and I *never* release the pressure from the tank, at least not unless I'm draining the water, which isn't all that often. I don't run it balls-out too often, but when I do moisture in the lines is rarely a problem because I use one of these:

've had it for the same 20 years and it works like a champ. WAY better than those glass bowl filters.

[Mike]

Have you ever consider the need to internally inspect the pressure vessel?

[dpb]

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[Jay Giuliani]

Another thing to consider is an auto drain assembly.

It is an enclosed ball and needle vale that drains the tank when ever the ball float goes above a certain level.

It is piped to the drain valve connection.

I have them on both compressors and they stay nice and dry.

I also use a filter on the line just in case.

Got everything throough Grainger's or McMaster Carr, I don't recall which.

> I've had it for the same 20 years and it works like a champ. WAY better

[Mike]

Ever seen the results of a pressure vessel failure? I saw one about thirty years ago that sent shrapnel over 50 yards.

In the UK, if the pressure vessel is used in commercial premises then

26 months is the maximum period between statutory inspections. The rest of the world may vary (and usually does!)

[dpb]

Mike wrote: ...

... Catastrophic overpressure failure is a completely different thing than the possibility of a rust pinhole developing after 50 years or so...

I'm simply commenting that daily water buildup in a low-use, low-volume homeowner/home-shop environment is somewhat excessive...

And, yes, I've seen results of high-pressure water/steam having been 30+ years associated w/ power generation facilities there have been a couple. But they're much higher pressure and much higher temperature events (1000-2000 psi, 600-1000F typical).

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[J. Clarke]

Yet another example of people living in unreasoned terror of their tools.

Anybody that worried about it should wrap it in a Kevlar blanket or stack some dead truck tires around it or something.

[Steve Turner]

Most air compressors of this caliber are never pressurized much above

100psi anyway. I can't imagine a tank "blowout" at this pressure causing much harm at all, other than a loud noise and perhaps some soiled underwear.

[J. Clarke]

Bingo. But if one is determined to be afraid of one's compressor then rather than agonizing over how it is going to explode and kill them one day they should take steps that allow it to explode with impunity and then stop worrying about it. Of course if they aren't happy unless they're worrying about something I guess a compressor is as good a target for recreational worrying as anything.

[dpb]

The tank itself (particularly if it is ASME-rated; some of the no-name imports that aren't rated I might worry just a little about a weld failure) is pretty unlikely to be an issue.

What I have seen that can be injurious if not lethal is the shock-induced fracture of larger plastic pipe used as reservoirs in a shop air system. It was cold (-20F outside, unheated shop building probably about 0F inside) and a tool fell from a wall hook and hit one of these. It scattered pieces around like that if got you in a tender spot could have done some damage.

I abandoned the idea of plastic lines then and there for the barn. :) Altho I think a 1/2-3/4" distribution line wouldn't have sufficient material volume to be a major deal, I decided it wouldn't be a smart idea even if cheaper... :)

That was ages ago long before I ran across the OSHA directives, etc., ...

[Tom Veatch]

. Never seen that term before, but it captures the concept beautifully!

Tom Veatch Wichita, KS USA

An armed society is a polite society. Manners are good when one may have to back up his acts with his life. Robert A. Heinlein