Air Compressor Help for Volunteer Fire Dept

[OldracerJones]

Our local Volunteer Fire Department has a 135 PSI, single stage compressor that has been here for years. Our Engine and Tanker require 120 psi in the tires but the most we can get in the tires is 98 psi. Gage at the compressor reads 135 psi but tire fill gets real slow and will not fill above the 98 psi mentioned.

What size/type compressor do you suggest for our inflation needs?

 

[BuffettFan]

If I were buying one, I would want at least a 5 horse, two stage with a 60 to 80 gallon tank running 150 to 175 psi.
Do you have a cascade or any way to fill your SCBA tanks? We used to have cascade in our rescue truck for filling tanks on scene and could also regulate it down to 150 psi for running air tools. That would fill your tires.

 

[sberry]

When 60A service was common 3 hp 2 stage was more popular for mechanics, now we are on 100A service and better, 5 hp has become more competitive.

 

[redmondjp]

If you are only airing up tires (and not using very much compressed air), a prosumer-grade 2-stage unit from a box store should work just fine.

 

[sberry]

Yes, it doesn't have to be great. Someone did ours and they use tiny air brake line for plumbing. Wouldn't have been a bad idea and it works I guess but would have used 1/2.

 

[Stillgottimefor1]

Try a different (bigger ) hose and check your air chuck. A big pressure drop from the tank through the hose may indicate a problem there. Worth a try. Test the actual output pressure at regulator, gauge could be wrong. Something here not making sense...


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[bamawildcat]

Our local Volunteer Fire Department has a 135 PSI, single stage compressor that has been here for years. Our Engine and Tanker require 120 psi in the tires but the most we can get in the tires is 98 psi. Gage at the compressor reads 135 psi but tire fill gets real slow and will not fill above the 98 psi mentioned.

What size/type compressor do you suggest for our inflation needs?

While shopping around, also check to be sure if there is an in-line regulator somewhere in the line between the compressor and the connector on the end pipe.

 

[Citation]

Given the slow flow rate as you finish the tire this has nothing to do with hose diameter etc. One of three things is happening.
1. The tank gauge is wrong and you aren't getting more that 95 psi in the tank.
2. The tire gauge is wrong.
3. Something is up with the regulator and you aren't getting full pressure in your line. Do you have a pressure gauge after the regulator/ near where the hose attaches? Does it agree with tank pressure?

I do agree that you don't need much more that a $150 compressor to get one that has about 150 psi of tank pressure.

 

[strutaeng]

Our local Volunteer Fire Department has a 135 PSI, single stage compressor that has been here for years. Our Engine and Tanker require 120 psi in the tires but the most we can get in the tires is 98 psi. Gage at the compressor reads 135 psi but tire fill gets real slow and will not fill above the 98 psi mentioned.

What size/type compressor do you suggest for our inflation needs?

What compressor do they have? Model number? Being a firestation, I would guess a higher quality unit than anything available to a consumer?

Are you sure the gauge is correct? Can you swap another gauge to confirm? If you have 135 psi at the tank, then you should be able to get 120 psi at the tires.

If the compressor pump seems to be pumping up correctly (time the pump-up time and post the time,) you can adjust your pressure switch slightly up, say to another 5 psi without much detriment to anything.

Do you have a regulator? Is it working properly? Plumb directly from the tank?

I hope this helps.

 

[Kaizen]

I’d make sure the hose is in good shape as well. Easy to bring in one and verify the interior of the hose is not deteriorating and becoming an issue. Next is the gauge used at tire. Should be able to just eliminate four items and be fine with that compressor


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[The Cobbler]

I suspect the regulator is the bottle neck.
have a look and see about tapping in a line before the reg and use tank pressure to fill .
if the tank pressure gauge is correct @ 135psi, you should have no problem filling 120 psi, albeit the closer it gets to 135 the slower the air transfer will be, but it should still be fairly quick

 

[NUTTSGT]

Do you have air bags that fill off an SCBA bottle ? If you do, you should have a regulator that screws on the bottle and has a typical quick connect fitting that can be used to fill tires via air hose& chuck.

 

[Ole Slewfoot]

Given the slow flow rate as you finish the tire this has nothing to do with hose diameter etc. One of three things is happening.
1. The tank gauge is wrong and you aren't getting more that 95 psi in the tank.
2. The tire gauge is wrong.
3. Something is up with the regulator and you aren't getting full pressure in your line. Do you have a pressure gauge after the regulator/ near where the hose attaches? Does it agree with tank pressure?

This.

You could always use truck air

 

[NUTTSGT]

I snapped a few pictures of our regulator. Left pic, shows SCBA fitting and right pic is a typical quick connect fitting.

 

[Leaflessshadetree]

Our station has a 33 gallon Craftsman oilless compressor. Works fine. About all it is used for is topping off the tires.

IMO a SCBA bottle, regulator and short hose would be a lot easier to carry around and reach all the trucks.

 

[Milton Shaw]

One thing that just about everybody should invest in is a master tire gauge to check all their other gauges with. Some thing around $25 on Amazon and guaranteed accurate to 2lbs full scale. Most Milton style tire inflaters can be calibrated by removing the cartridge and adjusting the spring tension and then locking it in position. Most tire store gauges are off as the current generation of techs don't know to check gauges and just assume they are accurate. As long as you know your regular gauge is 4 lbs off you can use it just making allowance for that 4 lbs. Master tire gauges are not designed to be used everyday for checking tires just occasionally for checking gauges.

 

[OldracerJones]

No regulator after tank, good idea we will put in place. I have a digital pressure gage from Eastwood I can check and compare with my home compressor which works fine. Since we just use it for filling tires and a few air tools. Thanks for everyone's help.