Question about compressor line slow leak

[NelsonC]

I have just finished installing the supply line in my shop, used 3/4" line from Maxline. The process was ok, took me about 2 days to complete the install.

There are a total of 3 outlets, 2 are connected to 50' reel, 1 has a quick connect on. there are 2 Tees total. Total line length is about 55'.

Now, after the install, I let the system charge until the compressor shut off at 157PSI. I turned it off and left it that way for 20 hours. After 20 hours, the pressure gage on the compressor shows 70PSI.

Is that too much of leak in my system? I guess at this rate, my compressor would kick in every 7 hours. I suppose it's ok to let it run once every 7 hours, or is that too much leak.

 

[gungatim]

IMO, yes way too much. mine will sit for days before dropping enough to kick on the compressor if I leave the lines pressurized (when I occasionally forget and leave on).

find the leak(s). I would think you would be able to hear it at that rate. you could even have partially blown an o-ring on the reel if running that high a pressure.

Also I wouldn't be running full 157psi through the lines, regulate it down to 90-100 as most tools require.

 

[NelsonC]

Sorry, I was not clear, there is a dryer and regulator before it goes into the line, I had it set at 100PSI.

 

[doojus]

I just installed a 1/2" MaxLine system and while the actual hose is a great product, I found that the manifolds and air drops were a PITA to get to seal. I found that every single one of the air drops leaked when I did the soapy water test. I ended up taking every one of the air drops off and reapplying teflon to the threads and then torquing the fittings as tight as I could with large wrenches.

For the manifold, no matter what I did I couldn't get it to stop leaking. I even tried a new one thinking maybe I had ruined the threads. I ended up just using a T fitting instead of the manifold. I think the 3/4" system doesn't come with one of those, so you're probably just losing air from the air drops.

 

[NelsonC]

Well, I will have to do a soapy water test. I will try to find as many as I can and see if they can be tightened even more.

 

[doojus]

FWIW i found that none of the T or union joints leaked, just the machined aluminum blocks. If you find that they leak just redo the teflon tape and tighten them until your wrench is about to break and then tighten them some more.

 

[jimbbski]

On threaded connections I prefer to use a paste sealer rather then Teflon tape. It seems to seal better and is easier to apply.

 

[arbormatt]

FWIW i found that none of the T or union joints leaked, just the machined aluminum blocks. If you find that they leak just redo the teflon tape and tighten them until your wrench is about to break and then tighten them some more.

I'm not sure if you are insinuating tightening connections at the aluminum block until your wrench is about to break? We have had guys get way too ham fisted on a lot of our aluminum blocks and actually rip threads out. Use a decent sealant and be careful with aluminum.

 

[doojus]

I'm not sure if you are insinuating tightening connections at the aluminum block until your wrench is about to break? We have had guys get way too ham fisted on a lot of our aluminum blocks and actually rip threads out. Use a decent sealant and be careful with aluminum.

I said exactly what I was purported to insinuate, what else could I be saying? It was an exaggeration obviously.

 

[arbormatt]

I said exactly what I was purported to insinuate, what else could I be saying? It was an exaggeration obviously.

Not trying to be a **** but if you are going into aluminum with a good sealent, a little past snug should be fine. It is no fun having to drill out holes and install helicoils because someone decided to torque on aluminum.

 

[doojus]

^cool you just saved OP a ton of time, he's all good since he already got them snug.

 

[arbormatt]

Just use a quality dope. Unless you are cutting your own threads you cannot count on thread quality. Well applied dope over Tef tape any day. I just finished an install at one of our plants. We ran over 2000' of 2" black pipe hooked up to two 50 hp Kaeser compressors and no leaks. Maybe doojus can advise me for the next job.

 

[doojus]

Maybe doojus can advise me for the next job.

Nah we leave advice up to know it alls and you obviously got us covered on that front.