Air system pressure leak

[antman213]

I have an air system that Is 100' of 1" pipe and An 80 gallon tank.. What is a reasonable amount of air loss?

I'm losing about 15PSI per day if the system is left untouched. This is not enough flow to detect easily.

What would you do? Is it worth digging into?

 

[ZRX61]

Do you not have a shut off valve on the tank?

 

[Worsedog]

Soap bubbles should easily find that. Then decide.

 

[thammel]

Believe that's more loss per day than you should have. Use leak detector solution. Try with compressor valved off to try and identify what part of the system is leaking.

 

[yatg]

Check your pipe, the quick connects, the drain valve, the pump to tank piping, IOW everything because the leak could be anywhere there's pressurized air.

 

[TurnipTruck]

I had at least 80’ of 1” galvanized and an old (new to me) 60 gal IR. First couple of tests it wouldn’t hold overnight. I tracked it down to the compressor. After some heavy use and some heat cycles, whatever was stuck on a valve finally broke loose and now it holds for months.

 

[larry_g]

If you leave it for 2 days does it loose 30 PSI? If you note the pressure at a time when the system is full of hot air it can easily loose 15 psi as it cools. Note the pressure in the morning when cool and if not run for a day does it still loose 15 PSI?

lg
no neat sig line

 

[Shop-hound]

Soapy water on all your fittings - watch for bubbles. In the pipe fitting world we call this “snoop”. Works really well. Can also isolate your tank from your pipe run (if you have a ball valve at your outlet off tank and see if it still loses pressure to determine which section of your system is the issue

 

[May Pop]

Don’t forget the stems on any valve with the soapy water

 

[rayra]

who leaves their system on and pressurized all the time? And why?

 

[Wrench97]

who leaves their system on and pressurized all the time? And why?

A guy who worries about .625 psi an hour leak........................

 

[mogandave]

who leaves their system on and pressurized all the time? And why?

I would not leave it on, but a tank full of (nice dry) air will do a lot of jobs without having to run the compressor and refill the tank.

 

[antman213]

A guy who worries about .625 psi an hour leak........................

I only installed it a few months ago. So its been in "Test Mode" since then.
Main reason I ask is I heard somewhere that most systems have 20% or so in losses and whether I should even worry about the leak.
Its small enough and on a large enough system that it probably isn't worth chasing, especially since I used X-pando on some of the fittings. Not planning on touching those

I probably would leave it on 24/7 just because the unit is burried behind job boxes, carts, and a few pallet jacks. and I like blowing stuff off at random.

 

[antman213]

If you leave it for 2 days does it loose 30 PSI? If you note the pressure at a time when the system is full of hot air it can easily loose 15 psi as it cools. Note the pressure in the morning when cool and if not run for a day does it still loose 15 PSI?

lg
no neat sig line

Thats pretty much the case. Left Monday at 115psi, came back Thursday morning at 85psi.

 

[May Pop]

15 a day is A lot of wasted air. I like a full size valve directly after the compressor before the flex and before any item like a hose reel. This serves 2 purposes. One to isolate each item when looking for a leak and second no reason to empty the whole system to do a repair or change a leaking coupler. Also as hose reels age they have the possibility of leaking at the swivel. You could shut it off at the valve and not loose air. I also leave air in the system to blow off something or fill a tire etc.
Remember air is money.

 

[BillK]

who leaves their system on and pressurized all the time? And why?

A lot of people apparently do but I am not one of them. I can just see something happening when I am not around and the compressor running for hours on end.

 

[NUTTSGT]

A lot of people apparently do but I am not one of them. I can just see something happening when I am not around and the compressor running for hours on end.

Exactly why I shut my off at the tank. Mine has a small leak but I flip the ball valve when I need air and don't need the compressor to run when I'm not there.

Granted I might hear it run once a year or so when the tank leaks off just enough to trip the low pressure switch between cycling when I have been out there.

 

[karoc]

In pneumatic world of controls, we would go drug store buy small bottle of peppermint. At source of air put few drops in line then turn your air on. Where ever you smell peppermint you will find air leak.
But if you have access to that 100’ run bubbles would be better

 

[antman213]

I do have a ball valve after the tank, as well as a regulator. I will start the investigation this week lol

 

[PoorUB]

who leaves their system on and pressurized all the time? And why?

I leave mine pressurized all the time. I do shut off the compressor when it is not in use.
I like being able to walk in and have air right now instead of waiting 5 minutes.

As for leaks, mine will drop enough to turn on the compressor in maybe 10 days.

 

[DenisG]

Check the diaphram on the pressure switch. Those are not always easy to diagnose because of covers, springs, tubes, and wires, but sometimes that's where the problem is and you can only tell by taking one apart. I think that some pressure switches have bleeders to deliberately bleed the tank down when it is not used in a while.

 

[Bill T]

If you are just checking a few connections, Windex works fine to detect leaks

 

[csp]

Mine is pressurized 24/7 (but not powered) with no noticable pressure loss. I'm sure there's some, but not enough to have it ever immediately turn the compressor on when I flip the power on. There are times I will go two weeks without turning it on.

 

[firebirdparts]

who leaves their system on and pressurized all the time? And why?

So I do. As far as the reason why, it would take a lot of time to depressurize it. i could just open a valve, put my fingers in my ears, and run, I guess, but I have no clue what the benefit of that would be. The anti-benefit, obviously, is that when I want air I would have to wait for it to fill back up. I could isolate the compressor tank and cut down the time required, but I don't know why I would.

 

[Imatk]

From what I understand if you leave a compressor pressurized you'll get more condensation as the air temp varies and then more water= more rust in the tank, and more water in your lines.

I always drain mine when I'm done for the day just in case.

 

[Wrench97]

From what I understand if you leave a compressor pressurized you'll get more condensation as the air temp varies and then more water= more rust in the tank, and more water in your lines.

I always drain mine when I'm done for the day just in case.

The moisture comes from the hot compressed air cooling, once cooled it will not produce any more moisture then a empty tank.

I leave the tank full but shut the electric off and the ball valve on the line off the tank, at one time we left it on with a hose outside to fill tires as needed but one holiday weekend someone needed the hose more then we did we came in Tuesday morning to find pieces of compresor all over the floor, the belts off and the electric motor still running.....................................

 

[antman213]

More air equals more water. If you add a cycle by depressurising and then again pressuring you will add more water. Although if you depressurize from the drain it will get it out of the tank though

 

[NUTTSGT]

I leave mine pressurized all the time. I do shut off the compressor when it is not in use.
I like being able to walk in and have air right now instead of waiting 5 minutes.

As for leaks, mine will drop enough to turn on the compressor in maybe 10 days.

No reason to drain the tank, just shut off the pipe, plumbing or system. A simple quarter turn of a ball valve and the system is recharged.

 

[Imatk]

This seemed like a good article... short story, should you drain your tank immediately after use... it depends

https://toolsaction.com/how-often-to-drain-air-compressor-tank/

 

[mogandave]

It's nice to have a spitter/electric condensate drain valve that will keep the water from building up in the tank, but will not open when the power is off.

 

[TractorJeff]

Every year there are numerous Threads on here as to why and how you should power down a compressor when you are not out there. Safety/Cost/Wear! Mine is pressurized 24/7 BUT the Switch is OFF till needed! For me it is a Safety, then a Cost thing. If the tire is low and I am ready to go. I have more than enough in the Tank to fill multiple Tires! Then recharge the next time I am in the Shop and going to need Air!

 

[Wrench97]

This seemed like a good article... short story, should you drain your tank immediately after use... it depends

https://toolsaction.com/how-often-to-drain-air-compressor-tank/

Unless you are pulling the tank into a vacuum there is still air in the tank...............................and condensation, just not under higher than atmospheric pressure.

 

[Citation]

This seemed like a good article... short story, should you drain your tank immediately after use... it depends

https://toolsaction.com/how-often-to-drain-air-compressor-tank/

This seems like a questionable conclusion on the part of the TA writers.

Let's break this down a bit. Why do we have condensation in the tank? Well air has water vapor in it. To get that vapor to condense we need to lower the temperature of the air below the dew point. Normally, your 75* air on a 60% humidity day has quite a bit of excess capacity for water vapor. Nothing in your shop, save that cold beer bottle, is cold enough to condense the water. However, when you compress the air the dew point goes up. So long as you also raise the temperature of the air the water can stay suspended. This is why the hot air coming out of the pump head isn't accompanied by liquid water. As the water cools in the tank we pass the dew point and water can condense on the surface on the tank and then collect in the bottom. So basically we get water in the tank because we cool the air back to around room temp.

If we use the air right away, it may still be hotter and thus the dew point is a bit higher. But that doesn't really help much if we say filled the tank this morning and used the air in the afternoon. If we use a lot of air then the air in the tank can drop to below ambient temp and you will get additional condensation.

But if you just fill the tank up then let the temperature stabilize you generally won't get any additional condensation. So filling it at 8AM then using that air around lunch time today or lunch time next month would only change things if the tank gets cool and night (thus more condensation). I see no advantage in draining the pressure vs just leaving the tank pressurized. If things were stable for a day they are likely stable for a month (again, drain the water after use).

I guess if you want to be picky you can say, "well it will get colder and night" but I can also just drain a bit more water then next day. If the drain is easy to get to drain it frequently. In absolute terms it is safer to drain the tank and you are less likely to accidentally leave the compressor on if you drained it of all pressure (on is kind of obvious at that point). I like having air at the ready but if it's been over a month since I used air then I guess waiting 5-10 min for the tank to fill isn't too bad (I liked that my small roofing compressor filled in 1 min).

Anyway, I think the source was offering more of a wives tail than solid reasoning.