New Compressor - question

My question is, between uses, what's the best way to leave it: shut it off and bleed off the pressure, shut it off and leave it pressurized, or leave it on to maintain pressure? I'd like to do whatever I can to keep it in good condition.

Our climate is dry, but even so, I notice that when I bleed it using the draincock at the bottom, a little moisture comes out. I have been bleeding it unless I know I'll be using it the next day. I bleed with the pressure relief until pressure gets low enough that it won't stay open without holding it open, then open the draincock. The moisture that comes out isn't much, but enough to leave a damp spot under the draincock where the air hits the concrete floor, and to tell that it is just a little discolored form light rust? Even though it's "oilfree" should I be oiling somewhere?

Another comment and question - I have noticed that when I open the draincock, as the pressure gets down, it sputters, and somtimes stops bleeding without bleeding all the way down. Yesterday when I used it, I noticed that when I closed the draincock, it didn't shut all the way off. When I finished the work I was using it for, I pulled the draincock and noticed that the o-ring on it was chewed up - probably what was sputtering and probably the cause of the leak that wouldn't let me shut it off all the way. Is this a result of opening and closing it too often? I'll be getting a new o-ring, or if I can't find one, a new draincock, but I'd also like to prevent this from happening again.

The sputtering you are experiencing when you drain down the tank is from ice formation. Expanding gas cools very rapidly. This freezes the moisture in the air and blocks off the valve until ambient air temperature warms the valve enough to melt the ice again. We used to sell electrical cabinet coolers that used this principle of expanding gases to produce chilling air blasts down to -40C.

Your tank will rust. Nothing you can do about it.

Draining between uses is unnecessary. Compressed air is more expensive than natural gas. You are paying money to pressurize that tank, why waste it? I wouldn't recommend pulling the safety valve either. They aren't meant for repeated cycling, and the spring will probably sack out and start to pop prematurely.

Have fun with whatever you use it for.

I did find o-rings at the local True Value hardware at 39-cents each, so bought one and a couple of spares. That will do for now, but when/if it happens again, I like your idea about replacing with a "real" valve. For starters, a street-ell and extension nipple will save having to get down on the floor to reach under it to open the drain cock - I'm no fossil yet, but getting closer every day, and my knees thank you for the suggestion! :)

This drain cock has a knurled not wing "knob." I would probably have gone ahead and bought a replacement without an o-ring, but in fact, didn't get down to the air tool shop where I deal, so settled for the o-rings. Now I won't go that route, but will try your suggestion when the time comes.

Hadn't thought about not using the pressure relief valve to bleed it. Makes sense, but if so, they really shouldn't put that handy little ring on it - makes it seem obvious as the thing to do. You are also right about bleeding every time making for expensive air - will leave it pressureized in the future. In fact, I'm having some serious thoughts about making a semi-permanent place for it and plumbing across the side of the barn where I have my workbench, but allowing for easy disconnect to keep it portable. Maybe even run a connection out the side under my shed where I keep the tractor and implements.

Interesting comment on the ice as causing the sputtering - should have thought of that myself.

Thanks again for the good post.

Thanks again!