Air compressors

[kingofwylietx]

I have a fairly plain compressor, but I am employed by an instrumentation & controls company.....so I quickly upgraded:

-Nice high-flow regulator for better operation of tools.
-changed gauges to better liquid filled American made units.
-added a shut-off valve & replaced the drain plug with a valve.

The best upgrade was definitely the air regulator. It flows MUCH better than the ones that come on these units.

 

[tino_ale]

Hi all,

I have a 2HP 50L (13 gallons), oiled, simple compressor. It provides 133l/min at 7 bar (4.7CFM at 100psi). Got it for 110 euros which isn't bad IMO.

My plan is to leave it in the underground cellar that I have under my appartment. I intend to run a hose up the stairs, with a quick connect at the end. I intend to use it for blowing air mainly so I can adjust the output to approx 3 bar and won't need to change the setting often.

So my questions :
- is 3 bar low enough to change tool using the quick connect system while 3 bar still in ?
- is it Ok to leave the compressor connected to 220V and with the pressure switch on it's "ON" position 24/24 7/7 ?
- is there any problem leaving the compressor and hose under pressure 24/24 7/7 ?

My air consumption should be quite low so I'm not worried about heat.

I'm asking these questions because the user manual mentions disconnecting from the main and switching to "OFF", and emptying whenever not in use. I wonder if these are just general advise with no real technical ground or if there is actually good reasons for them.

Thanks 🙂

 

[TranquillityBase]

Hi all,

I have a 2HP 50L (13 gallons), oiled, simple compressor. It provides 133l/min at 7 bar (4.7CFM at 100psi). Got it for 110 euros which isn't bad IMO.

My plan is to leave it in the underground cellar that I have under my appartment. I intend to run a hose up the stairs, with a quick connect at the end. I intend to use it for blowing air mainly so I can adjust the output to approx 3 bar and won't need to change the setting often.

So my questions :
- is 3 bar low enough to change tool using the quick connect system while 3 bar still in ?
- is it Ok to leave the compressor connected to 220V and with the pressure switch on it's "ON" position 24/24 7/7 ?
- is there any problem leaving the compressor and hose under pressure 24/24 7/7 ?

My air consumption should be quite low so I'm not worried about heat.

I'm asking these questions because the user manual mentions disconnecting from the main and switching to "OFF", and emptying whenever not in use. I wonder if these are just general advise with no real technical ground or if there is actually good reasons for them.

Thanks 🙂

Always best to play it safe...It's a metal vessel under high pressure.

 

[tino_ale]

So there's no way I can have readily available compressed air at all time ? 🤢

I have a remote switch upstairs so if it is unsafe to leave it under pressure at all time, I can switch the main off when not in use but I'll have to empty 50L of compressed air everytime I am done with what I have to do... The pressure switch will remain on "ON" position though. Is that Ok ?

Basically my concern is not to have to go downstairs too often (the place is way too full of stuff and it's uneasy to "navigate" through it).

 

[TranquillityBase]

So there's no way I can have readily available compressed air at all time ? 🤢

I have a remote switch upstairs so if it is unsafe to leave it under pressure at all time, I can switch the main off when not in use but I'll have to empty 50L of compressed air everytime I am done with what I have to do... The pressure switch will remain on "ON" position though. Is that Ok ?

Basically my concern is not to have to go downstairs too often (the place is way too full of stuff and it's uneasy to "navigate" through it).

Tino, you mentioned 'apartment'...is the cellar a common area for all the tenants of the building?

 

[tino_ale]

I have the appartement at the ground floor and the cellar under it is "mine". It is a private area and no one except me has access to it. :tinfoil:

Another option for the compressor would be outside, next to my front door there is a recessed area, sheltered from rain. But I would still be concerned about rust and all.

An explosion of the compressor (worst scenario I guess) would probably not injure anyone because there is no-one down there, it's just storage.

On the other hand the question is more if this kind of compressor is or is not designed to be under pressure all the time. I don't want to use it beyond what it's designed for. The user manual isn't clear about that.

It basically says "when not in use, disconnect from the main, put the pressure switch to "OFF" and empty the compressor".

 

[65535]

It's not bad practice to shut the compressor off and drain it, that being said, I leave mine on under pressure 24/7 I don't have any air leaks so the motor won't cycle on, the tank is rated for the pressure that the pump delivers and it's designed to hold that pressure and not weaken with multiple pressure cycles, so you should be fine.

But you will need to go down there to drain the tank every few uses, or best after every use once the air has cooled and all the moisture has condensed.

Since my thread got bumped I'll show you how I have my compressor setup now, since I've changed a few things.

 

[precisionworks]

I leave mine on under pressure 24/7

+1

With three compressors, roughly 200' of pipe, countless threaded joints, etc., my system always leaks a tiny amount of air ... even though I try to stop every leak. Pressure vessels don't need to be depressurized, unless you want to do that.

is 3 bar low enough to change tool using the quick connect system while 3 bar still in ?

No problem there. My shop system runs at 9 bar (130 psi) and every tool is easy to connect & disconnect. A dry nitrogen tank is sometimes used when more pressure is needed for an air impact wrench ... up to 14 bar (just over 200 psi) is used for really stubborn nuts, and the quick connect is a little stiff but still usable.

is it Ok to leave the compressor connected to 220V and with the pressure switch on it's "ON" position 24/24 7/7 ?

Yes and no. If the pressure switch welds itself ON (which is not unheard of), the compressor pump will run constantly. The safety relief valve will blow at some specified pressure, and the noise will wake the dead. The relief valve closes when the pressure drops, but opens again on overpressure. The pump will get extraordinarily hot and may seize up, which can cause the motor to burn up. Best to unplug it when it isn't in use.

 

[wquiles]

+1

With three compressors, roughly 200' of pipe, countless threaded joints, etc., my system always leaks a tiny amount of air ... even though I try to stop every leak. Pressure vessels don't need to be depressurized, unless you want to do that.

No problem there. My shop system runs at 9 bar (130 psi) and every tool is easy to connect & disconnect. A dry nitrogen tank is sometimes used when more pressure is needed for an air impact wrench ... up to 14 bar (just over 200 psi) is used for really stubborn nuts, and the quick connect is a little stiff but still usable.

Yes and no. If the pressure switch welds itself ON (which is not unheard of), the compressor pump will run constantly. The safety relief valve will blow at some specified pressure, and the noise will wake the dead. The relief valve closes when the pressure drops, but opens again on overpressure. The pump will get extraordinarily hot and may seize up, which can cause the motor to burn up. Best to unplug it when it isn't in use.

That sounds reasonable and safe :wave:

I personally have the compressor running during the day (with the small leaks that I have, it only comes ON like twice a day or so), but every night and every time I leave the house, I turn OFF the shop's "master" 220V switch, which provides power to my 220 tools (lathe, mill, and of course the Quincy compressor):

Now, I do leave my tank pressurized all of the time, but turn off the valve that feeds out of the tank into the external regulator/filter, so that it does not completely drain due to the small leaks. Then, every other day or so I purge any little water that might have accumulated at the bottom of the 60 gal tank. And then every week or so, I take a look at the Motor Guard M-60 air filter, and although never wet/moist, I swap it out for another one - I just keep alternating between those two filters 😀

 

[tino_ale]

Thanks for all the replies!

This is what I will do : leave the compressor downstair, plugged to the 220V, switch on. Whenever I don't use it, I'll cut the 220V from the switch I have upstairs to avoid any problem if the pressure switch welds itself.

I'll leave the compressor pressurized and I'll try to drain the water as often as I can.

About that : right now it has a tiny drain plug that is everything but practical! I intend to replace it by a larger ball valve.
-> can I drain the water when the tank is fully pressurized ?

The other option would be to get an auto-drain system as I understand they exist but I have no idea if it would fit under my tank (it's about 6-8 cm above the ground only) and how it works.

edit : just checked HF auto drain (BTW is it any good ?) manual and it looks like it would fit under my tank. I understand now how it works. I must add I can't believe the low prices. Here the compressor comes cheap but any kind of accessory is a rip-off 🙁

 

[65535]

You need to drain it under some pressure, because not all the water will be flushed by gravity, BUT the water will be rusty, and can stain if you let it sit a week or longer, it comes out fast when there is air pushing it out at 100+psi so it tends to spray.

Also don't open the valve just crack it, your ears and surroundings will thank you. I use a 1/4" ball valve on mine. I'll get some pics up in a bit.

 

[wquiles]

You need to drain it under some pressure, because not all the water will be flushed by gravity, BUT the water will be rusty, and can stain if you let it sit a week or longer, it comes out fast when there is air pushing it out at 100+psi so it tends to spray.

Also don't open the valve just crack it, your ears and surroundings will thank you. I use a 1/4" ball valve on mine. I'll get some pics up in a bit.

+1

I also had the 120V automatic drain on the bottom of the tank, but it was LOUD as heck, so I removed it and put a simple ball valve and a hose. Here is how it looked when new:

Here is how it looks now after several months of use:

 

[tino_ale]

Found HF auto drain on ebay, I think I might go for it. Just for the peace of mind I won't have to remember to drain the tank every now and then...

 

[wquiles]

Found HF auto drain on ebay, I think I might go for it. Just for the peace of mind I won't have to remember to drain the tank every now and then...

Just a heads-up, but at least mine was LOUD !!!

I disconnected it after it fired once :scowl:

 

[choffman]

Hi all,

I have a 2HP 50L (13 gallons), oiled, simple compressor. It provides 133l/min at 7 bar (4.7CFM at 100psi). Got it for 110 euros which isn't bad IMO.

My plan is to leave it in the underground cellar that I have under my appartment. I intend to run a hose up the stairs, with a quick connect at the end. I intend to use it for blowing air mainly so I can adjust the output to approx 3 bar and won't need to change the setting often.

So my questions :
- is 3 bar low enough to change tool using the quick connect system while 3 bar still in ?
- is it Ok to leave the compressor connected to 220V and with the pressure switch on it's "ON" position 24/24 7/7 ?
- is there any problem leaving the compressor and hose under pressure 24/24 7/7 ?

My air consumption should be quite low so I'm not worried about heat.

I'm asking these questions because the user manual mentions disconnecting from the main and switching to "OFF", and emptying whenever not in use. I wonder if these are just general advise with no real technical ground or if there is actually good reasons for them.

Thanks 🙂

If you have a regular schedule, you could always put a timer/time-clock on the circuit. Something like a 7-day "water heater" timer should easily handle the current draw. You just need to be sure that the contacts have a horse power rating. Most of the timers like this that we have in the states which can be easily obtained from the common retailers, have contacts rated for Hp. They are pretty economical (around $30US) and would probably pay for themselves over a period of time. Set the timer to turn on the compressor at the same time your coffee maker is set to and by the time you're ready to get to work you'll have air.

The only thing you'll have to remember to do from time to time is check the clock for the proper time of day in case you've had power outage.

That's just an economical suggestion. There are lots of other ways to accomplish the same results and "over engineer" the design for longevity.

FWIW

Craig

 

[TranquillityBase]

Found HF auto drain on ebay, I think I might go for it. Just for the peace of mind I won't have to remember to drain the tank every now and then...

I have one NIP, if you want it?

 

[65535]

Well I was getting tired of my compressors cheap regulator giving poor airflow and not regulating the air pressure very well, it was commonly 10-20psi below what it should have been when I set it.

So eBay supplies me a nice pair of CoilHose 3/8" regulators.

The only issue was the guage ports only read outlet pressure not line pressure, so I had to plumb the tank pressure guage into the pressure switch ports.

Flow is great and regulation is very precise, if anyone really needs a good regulator for their quincy or something these things are great.

 

[jasonck08]

I got given a used 2HP, 8gal sears compressor several months ago. It worked fine until just the other day it wouldn't power up anymore.

I couldn't find a fuse box, and the plastic that covers the motor I can't get apart because I think it may be using some funky star shaped bits to hold it together. It's also sunk in the holes 3-4" so I can't see it. But a phillips and flat head wouldn't turn it.

Do compressors usually have fuses? If so, would they be near the motor itself? I checked the other switch box and didn't see a fuse.

 

[tino_ale]

Just a heads-up, but at least mine was LOUD !!!

This won't be a problem where my compressor will be 🙂

If you have a regular schedule, you could always put a timer/time-clock on the circuit. Something like a 7-day "water heater" timer should easily handle the current

Not a bad idea, if switching on and off annoys me I might do that. But I don't use compressed air really often so the manual way might just do it.

I have one NIP, if you want it?

If it's rated for 120 psi or more, yes sir I am interested 🙂 PM you now...

 

[tino_ale]

Hi guys,

I have a couple of compressed air questions, since I'm getting an air impact wrench :
1/ I have no filter/water trap whatsoever on my compressor outlet. Is that a major no-go or can I still use it like that with my wrench ? If I need a filter/water trap, does a cheap HF do the job ?
2/ I have no air oiler either. I read here and there that a few drops of oil in the wrench air inlet before each use is Ok. Do you confirm this or do I actually have to get an air oiler ?
3/ Is it possible/viable to increase my compressor tank size with used butane bottles ? Wouln't look so good but would be a dirty cheap way to increase my tank size...

Thanks for any input 🙂