Draining Your Air Compressor?

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Jan 15, 2007
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Hi Everyone,
I recently got a nail-gun/compressor set from Porter+Cable -- the one with a brad nailer, finish nailer, stapler, and a 6-gallon compressor.  I've used it on a few projects, and it's been great so far!

I've read a lot about draining the compressor.  After each use, I empty all the air from the compressor, then I open the drain valve and tilt the compressor so the water drips out.

I've noticed that, even after just a couple of hours of use, a fair amount of water drips out the drain valve.

So, for those of you with a lot of experience with compressors, here are a couple of questions:
1. Do you drain all the air out of the tank after each use?
2. Do you drain all the water after each use?  Can you really drain all of it out?
3. If I ran the compressor with the drain valve open for a few minutes, would that clean out the water better than tilting the compressor?

I've heard of automatic drain valves, and noticed this one from Harbor Freight:
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=42221

I don't usually buy too much from Harbor Freight, but I'd be interested in knowing whether this item is useful.  if not, can you recommend another similar one?  Is this kind of thing unnecessary?

Thanks everyone!

Matthew
 
  Matthew, I drain (bleed) the tanks after every use. And I too tilt it a little. It really is to help prevent rusting out the tank. Don't worry too much about it, I've had to problems, the rest of the compressor will likely wear out before the tanks rust too badly. My experience is from 15 years of almost daily use of my compressors.

ETA, I leave the drain valve open when not in use.
 
Matthew-

I''ve been using my Senco for a long time now.  I drain it at the end of the work day - every day, and often some water comes out.  It is nothing to worry about - just don't leave it for a couple of weeks/months.  My compressor just keeps on running.  My guess is that your PC unit will do the same.

I think that is why they have the valve there.
 
just drain the tank at the end of the day.tilt the compressor to get the water out,and keep the valve open until the next time.sometime i spray wd40 on the valve to keep it lub so that it is easy to open and close.don't worry about those auto drain,the tank is not going to rust in a day.you need to worry about lubricating the nail gun you have.put a few drop of pneumatic oil in the guns to keep them working good.if you live in a place that gets very humid,like where i am,you may want to put a air dryer on the compressor(it remove moister in the line).i don't use one.i use to have one of those pc 6 gallons,i burn it!! big time.it just kept on running until the motor started to smoke.i now use a emglo 4 gallons,and small 1 gallon senco that i use a lot.and love it !love it! love it! i use the emglo if i have a big job that requires lots of nailling.  hope this helps. good luck with your pc!      btw:the pc guns are not bad at all,I've been using them for a long time.
 
I guess I am in the minority here but I don't bleed off the pressure after every use. To my way of thinkig that means you will be cycling a lot more air through the unit, meaning more water too. If you leave the tank pressurized then you are only adding the air you have used, and little additional water, especially with the relatively small volume your nailers use. I do drain mine if I know I will not be using it for a stretch but only if has had a decent workout.
 
I have a Thomas 4 gallon, double-hotdog T-200ST compressor.  I drain both tanks every day that I use it. 

One problem that I found was the original drain valves were very difficult to tighten and loosen, so I replaced them with this guy: http://www.homedepot.com/prel80/HDUS/EN_US/jsearch/product.jsp?pn=100095680 ($3.15 at Home Despot).  It is MUCH better than the original valve.  But...

It turns out that multiple manufacturers make a similar valve.  I bought a couple at Lowes and at Home Despot.  The Lowes version were garbage and I took them back.  The Husky version at Home Depot is very smooth and requires an easy twist.  It makes the draining task much easier.

Quite frankly, while I like this Thomas "American Made" compressor, I'm disappointed that they installed cheesy drain valves.  Oh, well...  All's well that ends well I guess.

Regards,

Dan.
 
I only drain mine once a week or so. I don't think draining the tank of air and the little amount of water at the end of each day is needed (personal opinion) and having to run the compressor again to pump it back up from "0"....every day.

I would guess looking at your use, air condition (high humidity/dry) and what makes you comfortable is about the best way to decide.
 
Everyone,
Thank you very much for sharing your opinions here.  It's good to hear from those with more experience on something like this.

One interesting point: the instruction manual mentions a startup routine to do the very first time you use the compressor.  You're supposed to run the compressor for about 20 minutes, with the drain valve open.  This is supposed to blow out any water that might be in the tank.

It sounds like doing this "startup" routine once in a while, as a maintenance step, could be more effective than tilting the tank.

I really like the guns so far, and have used them on a couple of projects.

Now I'm looking to add that pin nailer.  I'm still considering the Grex and the Cadex (not to be confused with the vaguely similar-sounding Kapex).

Thanks everyone,
Matthew
 
Ahhhh... so the swishing noise coming from my tank when i move it is water ??? Wondered what it was ::)
 
I found that when I lived in GA I had to empty the tank quite often (nearly every use), especially in August. Back home in Oz I may do it once a month, if that.
 
I drain mine as I use it. The more use the more I drain it. If the humidity is higher I drain it more. A few years back we had a samller 30 gallon tank explode after years of rusting out from the inside. The tank was indoors but in Michigan the humidity is usually very high all throughout the year. That particular tank rarely got emptied. Now I live in Southern California and humidity is not a major problem but I still empty the tank often...
 
Ted,
What was that like -- having the tank explode?  Do I want to know?

Groggy,
Did you change habits because of the weather, or was it something else?  Are compressors less expensive in Australia?  (I'm only kidding, of course).

Matthew
 
Matt, It was very loud and thank God I was outside when it happened. One fellow worker was within 3' from this unit when it exploded and lucky it was under the bench and he was wearing ear muffs. I know he had to go change his shorts after it happened but no one was hurt, only a mangled benchtop...
 
Matthew Schenker said:
Everyone,
Thank you very much for sharing your opinions here.  It's good to hear from those with more experience on something like this.

One interesting point: the instruction manual mentions a startup routine to do the very first time you use the compressor.  You're supposed to run the compressor for about 20 minutes, with the drain valve open.  This is supposed to blow out any water that might be in the tank.

It sounds like doing this "startup" routine once in a while, as a maintenance step, could be more effective than tilting the tank.

I really like the guns so far, and have used them on a couple of projects.

Now I'm looking to add that pin nailer.  I'm still considering the Grex and the Cadex (not to be confused with the vaguely similar-sounding Kapex).

Thanks everyone,
Matthew
i have the grex.great gun!never failed!i don't know much about the cadex,but i think it is more expensive than then grex,either way i think you will be happy with any of them.  you don't have to run the compressor for 20 min anymore for start up.they just want you to run it to "break in"and to remove any moister caught in the tank. just remenber to drain the tank after each use.
 
Matthew, where I live now (Melbourne) there is very low humidity. GA in summer is oppressive, and I remember SC being 100deg and 98% humidity - not a fond memory.

Suffice to say that unless you go much further north in Oz, past Brisbane, the humidity is not really comparable to what you get on the eastern seaboard.
 
A good way to picture what 120 psi has the ability to do.

A loaded (80,000 pounds) tractor trailer traveling at 70 mph gets stopped with a working pressure 90-120 psi.

A few years back we had a samller 30 gallon tank explode after years of rusting out from the inside.

A while back a moisture trap drain bowl blew off a air line. It sounded like a cannon going off.
 
ejantny said:
A while back a moisture trap drain bowl blew off a air line. It sounded like a cannon going off.
I once cracked 120' of air line outside the bathroom window. There was a yelp and the window slid open with a hideously scarred face appearing. It was the missus, and she had been applying lipstick when I cracked the line, and she was not happy.
 
Matthew Schenker said:
.......One interesting point: the instruction manual mentions a startup routine to do the very first time you use the compressor.  You're supposed to run the compressor for about 20 minutes, with the drain valve open.  This is supposed to blow out any water that might be in the tank.........
  Matthew, running for 20 min with no load is to heat the grease that is packed in the motor allowing it to flow into all the nooks and crannys. The grease packed compressors have a shorter life than the oil ones, no a big deal if you aren't using your compressor hard.

Edited, it was getting late so I typed a fast response. The motor is not packed with grease, the crankcase is. Lubricating the crankshaft, connecting rod and so on.
 
You guys are scaring me now!  I've been using my compressor and nailers happily for the past couple of weeks, and now I'm picturing the tank exploding.

I'm only kidding (sort of) as I know the chances of it happening are slim.

But here's a related question: how much hose line could I run with this compressor?  Is this compressor strong enough to run adequate pressure through a 100-foot hose?  I'd love to get one of those hoses on a reel.  It would help neaten things in my shop, and I could run it to some spots of my house without having to carry the compressor out of the shop.

Here's a 50-foot example (looking for 100 feet, perhaps): Air Hose Link.

Thanks,
Matthew
 
Hi,

Don't want to be a nit picker here, but actually that truck gets stopped with spring pressure.  The air simply pulls the shoes away from contact.  As the brake is applied the air bleeds off and the spring pressure does the stopping.  That way the system is fail safe.  If an air line ruptures it fails in the all stop mode, not the can't stop mode.  Same system was used on the large diesel pusher motor coach we full timed in for four years.  While it "only" weighted half what the tractor trailer does, it still was a lot of mass to bring to a stop from 70 mph.

Jerry

ejantny said:
A good way to picture what 120 psi has the ability to do.

A loaded (80,000 pounds) tractor trailer traveling at 70 mph gets stopped with a working pressure 90-120 psi.

A few years back we had a samller 30 gallon tank explode after years of rusting out from the inside.

A while back a moisture trap drain bowl blew off a air line. It sounded like a cannon going off.
 
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