Does air compressor Max PSI really matter?

[lwg]

So I'm looking at tons of different air compressors and notice that some are rated at 135psi Max, some 155psi, some even 175psi. If compressor A has a max psi of 135 and compressor B has a max psi of 155, is it really something I would notice for standard home garage use?

What's really driving this question is that I am starting to lean towards the $399 Home Depot 220V 60Gal compressor that has a max tank psi of 135. I think the tank is probably rated higher but the regulator is the weak link.

[Wicked_S10]

The only thing it will really impact is air reserve. At 175 psi, you have more air in the tank than you would have in an equivalent volume receiver at a lower pressure. I would highly doubt that any of your air tools could handle a 175psi supply, so you regulate the line pressure down to 90 psi or so anyways, so other than capacity, it wont do a hell of a lot for you. I would presonaly shop for the compressor that has the highest air flow at 90 psi, and make sure it is capable of supporting your tools which are air hogs, like air drills, die grinders, da sanders, and the like.

Later,
Jason

[MMiller]

I know my air tools, impacts specifically work better on my service truck, and at home, then at most customer shops I work at. My truck and house compressor kick out at 150 psi. I am also running larger couplers then most of my customers do too. My impacts will break hardare loose easier and quicker at 150 psi, then at 135, 100, or 90. When tightening hardware with my 3/4 gun, I can get alot more torque on the fastener, when I let my truck build back up to 150, then hit the trigger. Then go to the next fastener, the compressor kicks back out, and hammer on it.

My $.02, get the compressor that kicks out at 150, or better. I don't run a regulator to keep my air tools alive. Tank pressure is line pressure. Even if you are going to be running your air tools 8-10 hours a day, every day, you won't be exploding any at 150 or 175 psi, JMHO. Every one of our service trucks kick out at 150.

Michael

[ZJim]

On the trail I have a 150 PSI regulator on my CO2 tank.. my IR impact hasn't blown up yet.. and it has plenty of power that's for sure.

[maxyedor]

The most important thing is CFM, just make sure your compressor can supply enough air fast enough for your most demending tool and you'll be fine.

[Jeepin Redneck]

We run 175 at my shop and have had no problems with my IR tools or my crappy $30 air ratchets, but you can deffinately notice the difference when I bring them home and run them at 135 PSI

[BumpyDodge]

Tank size (reserve) and CFM (airflow at XXXpsi) are more important. 120 psi is enough to run just about any air tool. It's running out of flow that limits what you can do.

That's why some people bump their regulators up in the 140's/150's - if you don't have high flow, you need the initial "hit"" of higher pressure to break a nut/bolt loose with your impact gun. With low CFM and a small tank, you'll run out of pressure fast.

If you want an idea of how much compressor you need- look at the different air tool cfm requirements listed in any decent tool catalog. To figure out how much compressor you need, pick the highest CFM requirement tool that you use on a regular basis and multiply that by 2. That way you aren't running your compressor at max load all the time. The compressor runs "derated" for the application instead of running balls-to-the wall. Usually CFM is rated at 90psi, but not always. Try to get a compressor at least up in the 10+CFM range if you can afford it. That will run most home-garage type air tools at normal pressures (running one tool at a time - without continuous use).

For example:
125 psi from a compressor with an 80 gallon tank rated at 18cfm@90psi using 1/2" air line will seriously outperform 150 psi from a compresssor with a 30 gallon tank rated at 5cfm@90psi using 3/8" air line. (even though the smaller compressor is running higher pressure)

Running higher than recommended pressures to compensate for not enough flow, or not enough tool for the job won't hurt most air tools if you only do it occasionally. It will make your compressor work a LOT harder. Higher pressure = higher heat. Heat kills compressor heads, (all those fins are there for a reason) so it's your call on what pressure you feel comfortable running.

If you use a sandblaster, or 3/4" or larger impact - use the biggest I.D. hose and fittings you can because these tools in particular need a LOT of airflow (not pressure - flow) to work right.

[KILLER"B"3]

My 80 gallon is set to cut out at 175psi but good to 225psi. The regulator is open to max and it has been for 15 years. I run the snap on regular 3/8 air fittings, but they have a 5/16 hole in them instead of the normal small hole. They are a tad shy of = the 1/2 fittings. Along with 1/2" air line, boy oh boy does it work. I hate going to buddies shops and working with there tools. Call me spoiled... but I did it to myself lol...

[darkstar]

Like most people said, its the air delivery volume (CFM) that makes the most difference. I have a 5HP single stage IR compressor that maxes at 135 PSI but delivers almost 20CFM at 90, and it will run circles around smaller compressors (two stage units) that deliver higher pressure but less volume.