Originally Posted by WalkGood
I'll bet there is a regulator of sorts built into the machine. Meaning, the compressor will run wide out if you are using all the cfms quickly and run slower if you are just using a trickle.
So, just open the valve a little bit after hookup to the irrigation blowout POC. After a bit you'll learn how much to open the valve without damaging things depending on how many zones you purge at a time.
Are there no dial gauges on the machine?
Ok so my update on this situation is:
After being told by the rental company (the mechanic and the sales guy) 5+ times "there is no way to control the psi output and there is no regulator" and "All the companys that rent these blow the systems out at 120 psi (its max)" So I reiterated they are foolish you have to blow out the systems at 70-75 psi or like EVERYONE on here said and the reason I even posted this in the first place...it can wreak havoc on the heads, nozzles, zone valves, etc.
So I went by the rental company and wrote down the serial number and model number, the compressor is a AirMan PDS185S. I called airman tech support and exactly like some of you said there IS a regulator it's on the right hand/back side right next to the oil separator filter. It's a simple though bolt with a jam nut to lock it in place making the machines psi/cfm fully adjustable from 50 to 120. So they admitted they were wrong and finally are going to allow me to adjust it. Even the AirMan rep said a air ram needs 50 psi and a jackhammer needs 120 so we would be foolish to make the machine without a way to adjust it. He said OSHA makes them put the regulator in a less accessible place for "safety" reasons. Thanks again guys