What does working pressure for a compressor mean?

M

Melbee

Guest
Hi Folks,
I have a 20A oil-filled (20 lt p/min) max. 85 psi with a 1.5 litre air tank. I was told the working pressure is 30 psi and would like to know what that means. Can someone explain it to me please?

A few weeks ago I took the motor off my old compressor and used the 3 litre air tank to add to my new compressor so I have a total of 4.5 litre air storage. At the moment I have my 20A compressor with 1.5 litre air tank set at 30 psi, which goes to the 2nd 3 litre air tank, which is set at 20/30 psi for my airbrush. I have read other people with this kind of set up have put the compressor psi, going to the 2nd air tank, set high (60 psi or more).
Should I do this? Say, 50 psi from compressor and 20/30 psi on 2nd air tank?
What if I want to do T shirts at airbrush 40 psi, should I put the compressor psi to 60?

Obviously I can't airbrush at 40 psi if my compressor psi is 30 psi (working pressure?!), can I?

Any insight really appreciated
Cheers Mel
 
As far as i know working pressure, is the pressure your compressor can maintain permanently at its rated cfm. It may have a max rating of 60 psi or whatever it is, but even under airbrush loads, only be able to maintain 30
psi under constant run conditions .

Thats my take from the wording. Without reading the compressor manual cant really tell you more.
 
Thanks wmlepage, actually the manual hardly says anything except its 1/6 hp and auto turns off at 6 bar (85 psi) and turns on when pressure drops to 4 bar (56 psi). It doesn't mention working pressure, it was the guy in the shop that told me it was 30 psi working pressure.

So generally painting at 30 psi or less is fine for continuous use but I can also do short sessions at a higher pressure?

If I set the regulator on my compressor at 30 psi (will run continuous fine), could I put the regulator on the 2nd air tank at a higher psi? Say 40 psi? Or not?
I'm thinking this will mean the pressure drops quicker and will turn on again sooner but the compressor is still only running at 30 psi. Am I right?

I hope I'm making sense :)
 
So generally painting at 30 psi or less is fine for continuous use but I can also do short sessions at a higher pressure?


Yes thats about how mine works even with a spare air tank in line, it just has more storage space, so when it does make up air and shut off, it just takes longer to run out.

If I set the regulator on my compressor at 30 psi (will run continuous fine), could I put the regulator on the 2nd air tank at a higher psi? Say 40 psi? Or not?

No, your tank in line would only be at the 30 psi your first regulator is set at.


I'm thinking this will mean the pressure drops quicker and will turn on again sooner but the compressor is still only running at 30 psi. Am I right?


As far as I can tell you are correct. In my set up, i have my compressor reg turned all the way up, a whole 60 psi, i then run an airline to a secondary 2 gal tank, out of that tank I run to a secondary regulator/moisture trap and do all my pressure adjustments at that point, unless I use one of the small valves on my hoses, I also run moisture traps on my hoses, I like to be thorough . Not that I have ever had moisture issues. One of the benefits of having an air tank in line is it is an extra moisture collector and easily drainable.


Hope I have not confused you too much.
 
When reffering to working pressure , and I may be wrong here (terminology differences) I figure its indicating what the pressure will be at the tool end..IE If you set your pressure to say 30 PSI on the reg and are running a long hose..The working pressure at the airbrush will drop to say 25 PSI, So if you do want say 30 PSI working pressure at the airbrush you will need to set ya reg at 35 PSI or there abouts as you will notice a drop..We set our working pressure by pushing the trigger and then adjusting the reg once we have the full flow going..Again soz I may be talking about something completely different to what was being explained to u..But if your compressor is rated to 85PSI, thats the max it can pump out. If say ya want to run about 40-50 PSI for tshirt work, just set ya regulator, with the trigger pushed down to 40-50 PSI and thats what it will be at the airbrush end..Good luck

PS With a two tank setup, you prob want to have to regs, just max the first one out on ya reg and let the pressure control valve shut of the compressor at its full PSI output capability (Prob about 85 PSI in your case, maybe a touch less) on ya second that controls the airbrush end ya set that for your desired output..) It shld in theory maintain 85 PSI (Or your max compressor capability) in both tanks.
 
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OK, if I understand this correctly,
I set my compressor regulator to around 70 psi (max 85psi) and my 2nd inline air tank regulator to whatever psi I want for my airbrush.

The working pressure for my compressor is 30 psi, so if I use any psi, 30 or under, with the 2nd regulator to my airbrush, it will run continously no problems.

I can work at a higher psi setting for shorter periods of time, like 40 psi for T shirts.

To set my airbrush air pressure I press the trigger down on airbrush and adjust the regulator on the 2nd air tank.
Have I got it?
Thanks alot guys
 
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