Leaving air in a compressor

[kywildcat]

If you use your compressor on and off during the weekend, do you drain the tank to "0" if you're not going to use it again til the next weekend. I left it full on Friday night and it lost about 2 pounds of pressure when I got out there Saturday morning.......is that normal??

Im sure this has been addressed before, but I cant find it. This is my first AC and I want to take care of it!!

 

[KEH]

I don't drain the air out of mine. Anyway, mine would lose more air than that, and I have a cut off valve at the tank. Sound like you have a good machine.

KEH

 

[6530]

2# loss overnight is fine. It could also be due to the hot compressed air coming out of the pump cooling off in the tank over the course of a few minutes, and as a result shrinking and yielding less pressure.

I leave my tank compressed 24/7 unless I'm going out of town. That way the compressor's always ready to use and there's less wear on the pump & motor since I'm not pressurizing for each use.

I have a ball valve just after the tank output that I close when I'm done & then I use a blowgun to depressurize all the hoses.

 

[Grumpy365]

. I left it full on Friday night and it lost about 2 pounds of pressure when I got out there Saturday morning.......is that normal??

Air pressure changes with temp.

If the temperature in the garage cooled down overnight you will lose some pressure.

Congradulations, You don't have a problem.

 

[rodm1]

If you have a tank 60 gallons or less I would keep it drained. Over that I just keep the water drained out of it. I tend to use the tank air for small jobs then when needed fire the compressor up it works well for me.

 

[nissan_crawler]

I can't imagine why you would drain out the money you spent in electricity. Seems like a complete waste. It's an air compressor, they're meant to hold air. Hell, mine hasn't been shut off in 6 years. If I want air, I WANT AIR. I'm not waiting for a compressor to pump up just to fill up a tire, or use the blowgun for a few seconds.

 

[ZRX61]

I have a 60gal tank, hasn't been drained to 0psi in at least 12 years... & there's absolutely no reason to do so.

 

[nissan_crawler]

I have a 60gal tank, hasn't been drained to 0psi in at least 12 years... & there's absolutely no reason to do so.

In fact, I would argue more reason not too. All that expansion/retraction is going to cause moisture.

 

[Gary S]

I have two compressors. My little 120v one is for the dirty work and it gets used in the winter when the temps go too low to even mention. My big 240v one gets used only when the weather is decent, so it gets filled in the Fall and sits all winter with air in the tank. I use air out of it all winter to fill tires or whatever until Spring comes or it gets low, whichever comes first. Then the little one picks up the slack and gets punished through the cold weather to finish the winter.
My 240v one has not been fully empty of air since I bought it. My 120v one has a leaky regulator that keeps it empty when not in use. A new regulator would cost more than it is worth.
Bottom line. Why waste air you already compressed and paid for? The more you run the compressor, the more water it accumulates.

 

[Rodger]

I've got a 60 gal. vertical tank compressor. The last time it was drained was when I moved to the new garage. It was lighter and easier to move without the 140# of air in it. LOL

Seriously, I never drain it. I just close the outlet valve and flip the lever on the pressure switch (so it can't kick on) when I'm not using it. There's no leaks and the tank holds pressure indefinitely. I have a manual drain that I blowdown every couple of days.

Rodger

 

[MTBob]

(This is somewhat off topic, but perhaps worth a mention .)
A few years ago I returned to my shop after a long weekend away. I found the air compressor running - a fitting gave out and it had been apparently running for a long time. The motor was really hot, and it seemed to me that it could potentially start a fire.
So, with a good bit of reluctance, I installed a 1 hour timer next to the air compressor outlet and I now switch the compressor on when I need air. It's a bit of a pain in the **** to have to reset the timer when I'm using lots of air, but when I leave I KNOW that if any portion of the air system fails it won't start a fire.

 

[blazsawgras]

i turn off the breaker to the compressor but dont drain tank. i may drain tank about every month to 2 months to remove condensation. but to answer the question i dont drain tank every time.

 

[ZRX61]

I just have a service disconnect next to mine & a ballvalve at the air outlet. No way it will fire up & run if a leak happens...

 

[kywildcat]

Wow......great answers! Thanks! I dont think I will be draining mine anytime soon then.

Rodger.....do you mean you open the botton drain **** on the bottom of the tank every once in a while to get rid of the moisture from the tank??

 

[BADSIX]

i leave air in mine all the time. my air compressor is in an small room on the back of my shop and is not easy to get to to shut the air vave off. but it dose keep it quiet in the shop. so i have a solenoid valve thats hooked to a switch at my exit door, i just flip the switch and it shuts the air line off.

 

[blazsawgras]

most compressors similar to mine have petcock on bottom of tank to drain moisture.

 

[tonydanzah]

I can't imagine why you would drain out the money you spent in electricity. Seems like a complete waste. It's an air compressor, they're meant to hold air. Hell, mine hasn't been shut off in 6 years. If I want air, I WANT AIR. I'm not waiting for a compressor to pump up just to fill up a tire, or use the blowgun for a few seconds.

this

 

[Gary S]

A few years ago I returned to my shop after a long weekend away. I found the air compressor running - a fitting gave out and it had been apparently running for a long time.

My compressor has an on-off switch as part of the pressure switch. I simply turn it off when the compressor isn't in use. It can't start that way.

 

[RAYJAY]

I just have a service disconnect next to mine & a ballvalve at the air outlet. No way it will fire up & run if a leak happens...

same here plus i have a light on the service disconnect. that way i do not forget to turn it off when leaving

 

[GeorgiaHybrid]

Mine stays on and pressurized 24/7 unless I am going to be gone for several days. I just shut off the power at the disconnect on the compressor and close the ball valve going to the main line at the tank. It hasn't been run down to 0 psi since I put it in.

 

[LIVELY]

60 gallon tank--been 10 years since drained other then just letting the moisture out

 

[e-tek]

i turn off the breaker to the compressor but dont drain tank. i may drain tank about every month to 2 months to remove condensation. but to answer the question i dont drain tank every time.

YIKES - Youonly drain the condensate every 2 months?? I leave my tank aired up, but drain the water out EVERY DAY it's used!! That's the law of compressors.

 

[e-tek]

Wow......great answers! Thanks! I dont think I will be draining mine anytime soon then.

Rodger.....do you mean you open the botton drain **** on the bottom of the tank every once in a while to get rid of the moisture from the tank??

EXACTLY! Drain it after every use.

 

[spongerich]

I love these sorts of threads. I'd always assumed it was a bad idea to leave the tank pressurized when it wasn't going to be used all week. I have no idea why, but it just seemed like the right thing to do.

Do you guys drain the moisture when the tank is at full pressure? I've always run mine down to 20-30 psi first.

 

[nissan_crawler]

Again, wasting money. The tank isn't going to blow up when you crack the schrader open, just go for it.

Although most likely insignificant, I would argue that pressure cycles like that weaken the tank.

 

[SnowBlaZeR2]

I love these sorts of threads. I'd always assumed it was a bad idea to leave the tank pressurized when it wasn't going to be used all week. I have no idea why, but it just seemed like the right thing to do.

Do you guys drain the moisture when the tank is at full pressure? I've always run mine down to 20-30 psi first.

I was going to ask the same thing. I usually pull the blow off valve or whatever the hell it's called. When it gets to around 30 I just open the drain on the bottom of the tank to blow out the moisture. You guys just open it at full pressure?

 

[nissan_crawler]

I was going to ask the same thing. I usually pull the blow off valve or whatever the hell it's called. When it gets to around 30 I just open the drain on the bottom of the tank to blow out the moisture. You guys just open it at full pressure?

When you want to blow water off something with the air nozzle, do you crank it down to 30 psi, or do you run it wide open? Why?

 

[bchee]

I love these sorts of threads. I'd always assumed it was a bad idea to leave the tank pressurized when it wasn't going to be used all week. I have no idea why, but it just seemed like the right thing to do.

I'm also surprised by the responses. I also just thought it "seemed" like the right thing to do. Now I'm not so worried about leaving it pressurized.

 

[SnowBlaZeR2]

When you want to blow water off something with the air nozzle, do you crank it down to 30 psi, or do you run it wide open? Why?

Depends really. I can control it with the air nozzle so I usually just go with whatever I have it set to, depending on what I'm doing.

The only reason I take it down to 30 is because it is quicker and easier to pull the valve out, than to climb down and open it up. I do that, clean up a bit and then go and open it up to drain any moisture.

So I guess what you're saying is that there is no issue with opening it up full blast? In that case, do you just do it long enough to purge the moisture, and then close it off again? Or let it all out?

 

[GeorgiaHybrid]

I just crack the ball valve on the bottom of the tank and let the water out. No need to let all of the air out of the tank or to lower the pressure before draining the water.

 

[ScaldedDog]

I leave my Eaton 80g pressurized all the time, but leave the pressure switch off when I'm not working on something that needs air. I set the auto-drain to run for 2 seconds every 10 minutes, and plugged it into a wall timer that is only on for 45 minutes/day. So mine get's drained for 10 seconds/day.

Mark

 

[Vinko]

I can't imagine why you would drain out the money you spent in electricity. Seems like a complete waste. It's an air compressor, they're meant to hold air. Hell, mine hasn't been shut off in 6 years. If I want air, I WANT AIR. I'm not waiting for a compressor to pump up just to fill up a tire, or use the blowgun for a few seconds.

One of the things that seems to always be emphasized in plant management is how much money is spent on air compressors and wasted on, for example, system leaks. I don't have any figures handy, but has anyone measured how much the air compressor costs them to use in their own garage or shop? And if you've ever repaired a leak, did you figure out how much that leak was costing you before it was repaired?

 

[williaty]

Huh, I'd always been taught to blow it down to 0 to get all the moisture out to prevent rust. I never though about blowing it down just until it stops spitting water and then leaving it pressurized.

 

[nissan_crawler]

One of the things that seems to always be emphasized in plant management is how much money is spent on air compressors and wasted on, for example, system leaks. I don't have any figures handy, but has anyone measured how much the air compressor costs them to use in their own garage or shop? And if you've ever repaired a leak, did you figure out how much that leak was costing you before it was repaired?

No, but I am horribly **** about stopping leaks. My compressor is on 24/7, and from what I can figure, it runs about once every 5 days. That's with no valves shut off, and an air hose plugged into it.

Huh, I'd always been taught to blow it down to 0 to get all the moisture out to prevent rust. I never though about blowing it down just until it stops spitting water and then leaving it pressurized.

If water isn't coming out, what moisture are you getting out? I put a quality ball valve on mine for ease of use. I crack it a little, let all the water run out, then open it wide open for a few seconds to blast anything else out, and shut it.

I don't understand why people are so insistent on wasting compressed air. Cycling tank pressure like that, just creates the very moisture you're trying to remove.

 

[usdemt]

I wired in a switch right next to the light switch so when I come into my garage I can just flip it on with the lights and it is ready to go when I need it, then when I leave I shut it off so it wont start in the middle of the night right next to my bedroom.

 

[kywildcat]

So it seems the most common answer is to to just open the bottom drain for a few seconds while tank is under full pressure to get rid of any moisture. (thats my take on it anyway). From now on, I will do that, and then just shut the power button off until Im ready to use it again. I cant imagine leaving it powered on all the time if your not going to be around anyway. Thanks everybody!!

 

[Kevin54]

Never drain my air down except when draining the moisture out of it. Once the moisture stops blowing I shut that petcock. My compressor is on 24/7. I'm like Nissan, when I want air, I want air. Hell my wife uses the air compressor just as much or more than me to keep her sweepers blown out of dust, or to keep her (really mine) John Deere blown off of grass buildup.

 

[Thruxton]

My 40 year old 2hp Craftsman has seen some very heavy duty, and for the last 12 years has been on 24/7 in my shop (permanently plumbed in with black pipe, although I will switch to galv. if I need to redo things). I fix air leaks if/when they occur, and it cycles from leaks less than once a month. However, every year I shut it down, drain the tank for 24 hours, and change the compressor oil (I could just heat it up to drive the moisture out, I guess, but easier to change it). I have drains on each outlet and check those each time I use a tool. IMHO, moisture is the great evil in an air system, from the compressor pump to the tool, and if you keep after it your stuff will last a long time.

 

[nismomans13]

I feel much better about leaving air in my comp all the time now.

 

[fr0mastaj]

Boy, after reading all of these comments, I feel like a dumbo for draining my 30 gal completely after every use (occasional weekend warrior). I will definitely keep it pressurized now...