Can I get more PSI out of my compressor?

fr

Diamond Member
Oct 10, 1999
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http://www.sears.com/shc/s/p_10153_1...ir+Compressors

I bought this compressor a few months ago mainly for filling up my car tires and cleaning out computers. It advertises 125 MAX PSI in large letters on the front. When I flip the switch on, it only fills to around 100 PSI and shuts off automatically. It wasn't an issue for me up until now.

I got a road bike and the the recommended PSI for my weight and tire size is 125 PSI. I can only get them up to 90 PSI with my compressor.

Can I overclock my compressor somehow?
 

mpilchfamily

Diamond Member
Jun 11, 2007
3,559
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This isn't the right place for this question. Heck not even the right forum. This involves mechanics not software or electronics.

But the max PSI rating on the tank is the max pressure the tank can handle. The compressor paired with it as you have found is a 100PSI compressor so that you don't overload the tank. If you need more pressure youll have to buy a better compressor, with or without a tank.

The compressor itself is limited by the motor running it. If you try to bypass any safety on it to allow it to pump more pressure you'll either burn out the motor or you'll blow out the taking and kill yourself.
 
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MalVeauX

Senior member
Dec 19, 2008
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http://www.sears.com/shc/s/p_10153_1...ir+Compressors

I bought this compressor a few months ago mainly for filling up my car tires and cleaning out computers. It advertises 125 MAX PSI in large letters on the front. When I flip the switch on, it only fills to around 100 PSI and shuts off automatically. It wasn't an issue for me up until now.

I got a road bike and the the recommended PSI for my weight and tire size is 125 PSI. I can only get them up to 90 PSI with my compressor.

Can I overclock my compressor somehow?

Heya,

If the compressor is rated for a specific PSI, it will not go beyond that by much (there is always a minimal standard diviation, +/-) because they use one way valves rated for a specific PSI value, and when that value is exceeded, the valve will not close and it will not allow you to gain more pressure--it loses the pressure. It does this to prevent you from blowing yourself up. If you were disable this and weld the valve shut so that it had no release valve, you could get more PSI into a reservoir, but only based on the amount of pressure the compressor's motor is able to generate. Once there's equal pressure in the reservoir than the motor/compressor is generating, air doesn't move, and thus pressure stops and the engine will stop working.

If you want an idea of how much pressure you're dealing with, so that you can appreciate the danger of compromising the safety of the compressor, note: 1 atmosphere, or 33 feet of seawater, or the typical atmosphere at sea level is equal to 14.7 PSI. When you dive underwater just a little bit, it hurts your ears, because the pressure increases, and that happens at just 8~10 feet easily. Every 33 feet is a new atmosphere. 120 PSI is 8 atmospheres, or the equivalent in pressure as if you dived down 269 feet into the water. If you were to let a compressor fill a reservoir to 120 PSI, and then have no safety valve because you `overclocked' the compressor to allow it to compressor higher than its safety valve would let it, you could easily end up having 120 pounds, every square inch, of pressure, hit you in less than a second in the face. Your face is probably about 6~10 inches tall, and 6~8 inches wide. Suffice to say, it's over 4,000~8,000 pounds of force hitting you in the head. If you live the blast, you will be a vegetable basically.

I suggest you don't fool with the compressor. Get a higher rated compressor if you need more pressure. And don't try to put more pressure into a tank/tire/reservoir, etc, than it is rated for. This isn't electronics where it just burns out and doesn't hurt you. Compressed air at high pressure is a bomb. Air under immense pressure heats up big time. You can also end up burning yourself with the air (cold and hot air both burn you, and the air will be very cold as it comes from the heated state of compression).

Very best,
 
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Fayd

Diamond Member
Jun 28, 2001
7,970
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www.manwhoring.com
http://www.sears.com/shc/s/p_10153_1...ir+Compressors

I bought this compressor a few months ago mainly for filling up my car tires and cleaning out computers. It advertises 125 MAX PSI in large letters on the front. When I flip the switch on, it only fills to around 100 PSI and shuts off automatically. It wasn't an issue for me up until now.

I got a road bike and the the recommended PSI for my weight and tire size is 125 PSI. I can only get them up to 90 PSI with my compressor.

Can I overclock my compressor somehow?

just pump em by hand. it's not like it's hard, and it's not exactly a huge volume of air you gotta put into the tire.
 

corkyg

Elite Member | Peripherals
Super Moderator
Mar 4, 2000
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What has this to do with computer hardware? Sheesh!
 

heyheybooboo

Diamond Member
Jun 29, 2007
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What has this to do with computer hardware? Sheesh!

Welllll .... technically, this is the General Hardware Forum.


:D


OP: 'Overclocking' your compressor beyond spec is probably a good way to make the local news --- or the 'Dumb Home Owner' column in your local newspaper.

Aside from a tank blowout I'd guess a fitting might possibly fail. I have witnessed a 'flailing fitting' on the end of a hose take a big chunk out of a concrete block.

Glad it wasn't my head --- LOL





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fr

Diamond Member
Oct 10, 1999
6,408
2
81
Thanks for the replies. I didn't necessary want to "overclock" it. Bad choice of words. My problem is the motor the cutting off sooner than it should. My best bet is probably to get a good floor pump.
 

jthunderloc

Senior member
Dec 28, 2009
606
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cool the tank while filling it. We used to do this while scuba diving. As the air is pumped in, it heats up. Hot = less dense. If you cool down the tank while filling you can pump more dense air in at the same pressure. When said tank returns to room temperature you will get a higher pressure in the tank. The air tank is going to have a burst disc that will pop and vent the tank before it gets to the max pressure. Trial and error. Fill it to 50psi in a bucket of ice water then see what pressure rises to. check what the burst disc fail setting is at.

Or, but a better compressor. This could end poorly, but more then likely would just blow the disc and require a trip to the hardware store

-Wes
 

heyheybooboo

Diamond Member
Jun 29, 2007
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Thanks for the replies. I didn't necessary want to "overclock" it. Bad choice of words. My problem is the motor the cutting off sooner than it should. My best bet is probably to get a good floor pump.

Don't make me regret this :eek: Anand, Inc and BooBoo, Amalgamated cannot be held responsible! (After all, consider my username - LOL)

You are dealing with 2 things:

1) the pressure switch; and
2) the regulator valve.

compress-1.jpg


I'll guess the gauge at the switch is reading higher than the gauge past the regulator valve. So that gives you 2 options:

1) adjust the switch; or
2) bypass the regulator.

To adjust the pressure switch remove the plastic cover (with all the 'hazzard!' warnings - LOL). The pressure switch is fairly simple. IF you can adjust the pressure-out it will most likely be the 'big-spring' assembly that looks remotely like this:

compress-2.jpg


If I haven't lost my mind the tighter you crank the spring the more (air) pressure it will take to 'open' the contacts to shut the motor off.

Like overclocking :)D) starting with a little 'lite cranking', monitoring the pressure gauges and testing the setup would be the way to roll. Safety First!


As far as by-passing the regulator valve:

1) remove the pressure gauge from the manifold, and disconnect the manifold from the air line that comes from the pressure switch; and

2) drop by your local auto/plumbing supply and buy 2 brass 'Tees', 2 90-degree fittings ('elbows'), 2 inline 'shut-offs' and some PTFE thread ('Teflon') tape. You will need to 'engineer' from available brass stock whatever additional bushings, barbs, fittings, couplings, etc., that you may need.

Install a 'T' at the pressure gauge fitting and reconnect the gauge. Use your tape! Connect the shut-off with a coupling to the manifold at the regulator valve.

"" T-off "" from the shut-off .... one back to the pressure switch and the other to the 'T' at the pressure gauge (install the second shut-off on this leg). By-pass complete! Probably cost around $30 or so. You might also find a really nice drain value for the tank for around $5-$6 that is much nicer (and easier on your fingers) than your current one. Drain the water every day you use it and the tank will last forever.

Most brass fittings in the 1/4-inch range have high PSI thresholds in the range 300-400 PSI ---- but always verify!


And hopefully we will not read about it in the news - LOL





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RD Mercer

Junior Member
Dec 31, 2009
14
0
0
I am guessing you are having problems pumping air into you tires? I had the same problem but I knew it was not my compressor. I needed more volume, so I bought a bigger ID air hose and that solved my problem.
 

fr

Diamond Member
Oct 10, 1999
6,408
2
81
And hopefully we will not read about it in the news - LOL

--

It looked like you put in a good amount of time into that post.

So I figured...why the hell not?

I made sure I opened my garage door and turned on all the lights so it would be easy to find my body should I need to end up on the evening news. I also emptied all the air out of the compressor just in case and unplugged it.

I took off the switch cover. It was just one screw holding it on.

100_0632.jpg


I saw more plastic covering underneath with a bunch of screws accessible from the top. All the screws were tight, except for two that seemed to have springs underneath. So I went ahead and turned them clockwise a few times.

I plugged the compressor back in and switched on the motor. To my delight, it filled up to the red line...and then a bit passed it. So I switched it off and turned the screws back in the other direction.

After a bit of adjustment, I got the cut off pressure right under 125 PSI.

100_0631.jpg


When I went to put the cover back on, I see there is a diagram on the bottom.

100_0633.jpg


So no need to buy another pump! Thanks heyheybooboo!