90, 135, 175 ??? What PSI do I need?

[Henro]

Hi,

My little old 20 gal. compressor popped a hole in the tank in the fall. I'm thinking of replacing it. It never had enough capacity to run an impact wrench or little sandblaster...not that well anyway. Yes, it did work, but ran out of omph pretty quick.

I could buy a 7 HP 60 gallon Campbell Hausfeld, 125 psi, ~10 scfm for $430+ or...

Or maybe a Ingersoll Rand 15.1 CFM @ 175 PSI, 5 HP Type-30 Electric-Powered Compressor, Model # 2340L5 for $1,000.

Or something in between.

I don't need much really. There have been times over the last ten years when that little 20 gallon unit was lacking, but most of the time it could at least struggle and we would get things done.

Seems like most air tools are rated at 90 psi...would I want more than 125 psi?

I'd like to do it right this time...20 gallons and 90 psi was not enough. What would be?

Hope air compressors are not like tractors! /forums/images/graemlins/blush.gif

Appreciate any pointers... /forums/images/graemlins/smile.gif

 

[AndyM]

</font><font color="blue" class="small">( could buy a 7 HP 60 gallon Campbell Hausfeld, 125 psi, ~10 scfm for $430+ or...

Or maybe a Ingersoll Rand 15.1 CFM @ 175 PSI, 5 HP Type-30 Electric-Powered Compressor, Model # 2340L5 for $1,000.

Or something in between.

Hope air compressors are not like tractors! )</font>

You could get one of each-- it worked for the Kubotas! /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif

 

[Joe1]

Don't you need to figure out the volume of air your hungriest tools would need and then add a comfortable margin and get a compressor to match?

 

[powerstroke2000]

the 60 gallon tank will be a big improvement
if you go with the 175psi you will need a regulator got mine set at 120 and the compressor starts at 135 which will also help with volume pressure

 

[Egon]

What about power supply? Can your existing circuits handle either draw? Is portability an issue?

For only occasional use think of economics and extra tools with the price difference.

Egon

 

[Youare]

The size of the holding tank will help some but the biggest factor is the CFM or SCFM of the compressor. If you decide to go to a compressor with a higher output pressure you will need to regulate the pressure to the tool.

Most compressors have regulators on the line out to the tool anyway so that is no big deal. If you want to operate a sandblasting gun or a spray gun you will find each item has a rating for the CFM necessary at a certian PSIG.

That is the number you want to match the compressor to. The 10 CFM unit will probably meet all your needs by the sound of it especially when you consider the size of the holding tank, 20 gallons vs. 60 gallons.

I have a 20 gallon 1 HP compressor which ran my fathers automotive repair business when he was alive. Some times you had to wait for the compressor to recover when using the impact wrench on a stuborn nut but that was not often.

I think you would be happy with the 7 HP 10 CFM compressor and the money you save could buy another nice new toy, I mean tool. /forums/images/graemlins/wink.gif

Randy

 

[Bird]

</font><font color="blue" class="small">( most air tools are rated at 90 psi...would I want more than 125 psi? )</font>

Yep, Bill, they're rated for 90 psi, but when that impact wrench won't break that nut loose, you can up the air pressure to 150+, like a lot of mechanics do, and that impact wrench has a lot more power. Of course you may break the impact wrench, but someone has to keep the air tool repair places in business. /forums/images/graemlins/wink.gif /forums/images/graemlins/grin.gif

Seriously, though, few of us ever need more than 120 psi, but as I'm sure you know, there are exceptions. The only time I can remember needing more was once when helping a neighbor with his hay baler (round bales), there was what I guess you'd call an air over hydraulic cylinder that called for 150 psi and neither of us had a compressor that would go that high. But another neighbor, full time hay business, did so we had to take it over there.

I'd say a 60 gallon tank with a compressor that will put out 10 SCFM is probably all you'll ever need, but if money's not a consideration, nothing wrong with a little overkill, but as you've already been told, you'll definitely want a pressure regulator, but you'll probably want one anyway. And if you get something like a big sandblaster, you need all the volume you can get.

 

[Hambone]

<font color="red">I could buy a 7 HP 60 gallon Campbell Hausfeld, 125 psi, ~10 scfm for $430+ or... </font>

This is what I have. Works well. Runs 1/2" impact fine. Can run a die grinder good. I also use a sheet metal nibbler and no problems. A decent home use compressor, IMHO.
Can't afford to add any sense($.00) /forums/images/graemlins/grin.gif

 

[RET]

Also, don't forget that the higher pressure, such as the 175 psi unit you mentioned, will give you more volume of 90 psi air when using high CFM tools (much more air is 'packed' into the tank at 175 psi than at 125psi). That means a longer period of time before the compressor kicks on to 'recover' when you are using tools that are near the limit of your compressor, and less cycling of the compressor during 'normal' usage...it's a compromise between tank size, pressure rating, and compressor size....and of course $$ For two tanks of equal volume, the one that runs at 175 psi will contain 40% more air than the one that runs at 125psi (175/125=1.4).
RET

 

[Henro]

Thanks for the input everyone.

AndyM...morre than one? Hummmm... /forums/images/graemlins/blush.gif

Joe1...can't predict the future yet! But I was more wondering about the pressure side...thinking that higher pressure would be good up to a point...

PS2000 sounds like if you find 120 psi output to work for you a 135 psi compressor may work for me...

Egon,

I do have enough power [100 amp 220v] in my shed to run whatever I might buy, but don't really have enough power in my pocketbook to buy more than I might need... /forums/images/graemlins/frown.gif

Also have a little pancake unit to carry around if needed.

Youare,

I am also starting to think that a cheaper, 60 gallon, 125~135 psi unit would be all I need...

Bird,

<font color="blue"> but if money's not a consideration... </font> Ha, Ha, I'm still looking for the road that will lead me to that place! /forums/images/graemlins/smile.gif What I am hearing is that I don't need to spend the extra buck for 175 psi that I almost will never need.

Hambone, glad to hear a "satisfied customer" report!

RET, I was thinking of rusty or highly torqued nuts more than high vol. air needs...I understand your point about vol. and pressure and appreciate the input!

So I think I am now leaning towards the cheaper compressor. 125~135 psi range. Seems like the best compromise. Home owner use, not business. More PSI to turn the impact wrench, more capacity to work air-gobbling tools I might end up with...less strain on the pocketbook...a step up from what I am used to...

Thanks for the help everyone!

Looks like you guys may have saved me some money and guided me towards the best value for my needs!