Leaving air preesure in the Compressor tank

[LCHIEN]

Some questions about compressor ownership and habits.

actually three sections, answer OWNERSHIP
if you own one then Answer about turning it off and draining it


How many of you leave pressure in the compressor and walk away at the end of the day?
Yeah, they recommend you don't do this.

[cabinetman]

My compressor is electrically turned off every night, and I have an air shutoff at the tank that also gets turned off. I leave the pressure in the tank and I usually bleed the moisture out everyday. I also have drains along the airline run that get bled periodically during the day.

[goslin23]

I have a small Craftsman compressor that I leave plugged in, turned on and the tank full. I'll drain it maybe once a week or when I think of it.

I know this is not recommended and it's probably not a good thing, but the thing is so dang noisy (it IS an oiled compressor) and takes a few minutes to fill up. The main thing I use it for is to blow the dust off stuff when I'm through working. I do use it for my nail gun and an occasional tire inflation. I'll probably want to start draining the thing every time I use it and leave it empty and off when I'm not in the shop though. I could simply turn it on to fill when I start my day in the shop. Might last longer that way huh?

-=gos=-

[cabinetman]

I have a small Craftsman compressor that I leave plugged in, turned on and the tank full. I'll drain it maybe once a week or when I think of it.

If you don't have a shutoff at the tank, and it develops a slow leak or a burst somewhere, it will kick on and stay running until it melts, overheats the circuit, starts a fire, and burns down the house. And it probably happened to a guy named Murphy when he went out of town for the weekend.

[jackellis]

I have a small Campbell Hausfeld that I usually leave pressurized but unplugged. It seels like the only good way to release the pressure is by holding open the pressure relief valve until it bleeds down. Is there a better way?

I do need to replace the quick drains (2) on my tank.

Assuming you leave it unplugged, what's the downside of leaving pressure in the tank. I use mine about once a month for no more than a few minutes so it's not like a lot of moisture accumulates, but I do worry about an explosion that will send shrapnel everywhere.

[Black wallnut]

Yeah! what exactly is the reasoning behind bleeding off the pressure? I can understand the need to remove any moisture and agree that one should leave it unplugged when not in use.

[radhak]

How many of you leave pressure in the compressor and walk away at the end of the day?
Yeah, they recommend you don't do this.

Yeah, sure, go ahead and add to my list of paranoias - things to check, remember, avoid, lock, ventilate, secure, protect, lubricate, dehumidify, organize, label, align, refresh the BT3C-page, and what not .

Not that I remember to do any of them at the right moment; it's just the list that grows longer .

I don't use my compressor all that frequently, so when I do, I tend not to drain it off at the end, with the idea that I'd use it to clean up some around the shop; at the most a week or so of undrained air, then maybe a couple of weeks of non-use. rarely do i leave it plugged it - prefer not to be startled by the big-bang noise of it's starting up unexpectedly.

[scorrpio]

I am blessed with an 'automagic' compressor when it comes to draining. The compressor I have was given to me for free, because its owner upgraded to something better and bigger. Despite all my efforts to tighten things up, it leaks. It drives my nailers fine when pumped to 90 psi, if you turn it off, tank will go from 90 to 0 overnight. I probably should replace it, but as long as this one works, just can't seem to get around to it. Maybe when there is some killer deal available...

[cabinetman]

Yeah, sure, go ahead and add to my list of paranoias - things to check, remember, avoid, lock, ventilate, secure, protect, lubricate, dehumidify, organize, label, align, refresh the BT3C-page, and what not

I can remember when I first got tools that had a safety built into the switch, that took me a while to get used to actuating in order to use the tool. I can remember when automatic transmission cars first came out with the safety of having to have the foot brake on in order to get it out of "Park". For stick shifts it was having the clutch engaged just to start the engine. It's just getting used to the "newness" of the task. You should get very familiar with the necessities in the shop for your own sake and as a procedural step that goes along with the tools. The more you use them, the more of a habit will be formed.

[LinuxRandal]

I can't pick any particular thing because it varies by use and compressor.

Years ago, there was a garage, not to far from me, whose compressor tank, split and blew (at least an 80 gallon), and blew a car that was on a lift (left the compressor on and the car in the air), across 78 highway.

So my pancake will get air left in it (tires, emergency road kit), and my big one will only be left fully pressurized if I intend to use it in the next day or two. Otherwise I drain it, and let most of the air out (not all), but have it shut off.

[LCHIEN]

Two websites I read suggest draining the water daily:


Maintenance Tip 2: Drain The Moisture From The Tanks
The receiver tank collects moisture from the air that it’s compressing - especially if you live in a humid climate. Most tanks have a valve for draining this moisture that accumulates and it’s up to you to make sure that these are drained regularly. Before draining the water you should be sure to release the air pressure from the tanks.



Daily Maintenance: You should drain moisture from your air compressor's tanks on a daily basis. Bleed most of the air pressure from the tanks before opening the drain valves, allowing all moisture to drain from the tanks.


That I can understand. But both recommend releasing most of the air pressure from the tank before doing so. I don't undestand this, I always crack the drain cock open with full pressure on, the water blows out quickly instead of drip-drip-dripping out. I mean gravity's the same whether pressurized or not... the water will be in the bottom of the tank and not be kept away by pressure? Seems to me like pressure helps drain quicker.

Anyone understand the reason behind releasing the air pressure before draining suggestions?

[footprintsinconc]

plugged, pressurized and ever so often drained

i have a 60gal husky (HD) compressor. i leave it pressurized. i just close the valve rubber hose and drain the air hose, so it doesnt remain pressurized.

its always plugged in, it automatically comes on when it needs to and i will loose air from that tank in about a week before it automatically turns on and fills up again. it takes a long time (or it feels like it does) to empty and takes a while to fill up (maybe 15 minutes, cant remember).

i drain it every three months or so. its pretty dry here in az. i just drained it yesterday, not much water at all. the first time i drained very hardly anything came out except a few red drops. now, last night (2nd time i drained it) i got about a 1/4 of a cup all red. i bought a used compressor. i am wondering if i should get some oil in the compressor so it inhibits rust, is that a good idea? if so how do i get a oil in the compressor? i have a water/oil filter before my hose line so that nothing gets thru.

[cabinetman]

Anyone understand the reason behind releasing the air pressure before draining suggestions?

Probably the lawsuits. I also drain under full pressure. There's not always just crystal clear water in the bottom of the tank. Sometimes there is a gummy oily sludge that needs to be forced out.

[LCHIEN]

Yeah, LOL, I have never seen any clear water out of mine.
Always something that looks like Beef stew gravy (only less appetizing).

I wonder if the tank rusts faster when its under pressure... more oxygen molecules (about 10 X as many at 10 Atmospheres) available for reaction... a common technique for speeding up chemical reactions is to add heat or pressure.

maybe I should release pressure when shutting down for the day (now that I've replaced the leaky HF Quick-connector and it holds pressure overnight)...

[Cheeky]

i have a Hitachi pancake compressor, which is reasonably quiet on the fire-up. i have to put on the ear prot. when i drain it.....friggin loud, but i do it after every use.