Air Pump

[cb5300]

I've seen an air pressure "booster" that you could put on your coach to increase the air pressure so that you could air up your tires. It would "boost" your pressure up to around 160 PSI (I think). Any info on this would be a big help. Also, I would love to hear from anyone that's actually have or used one of these systems....Thanks.

[RV Wizard]

The only way to increase air pressure would be with a compressor, hense the name. Have you tried doing a Goggle search?

[wa8yxm]

Well, having a Gasser I use a sears 150 PSI portable electric compressor

It is possible to make an air pressure booster, I know how to do it in fact. I don't know if anyone does it though

To do it you basically need two pistons, one large, one small, and some valves. Air pressure is applied via a valve to the larger piston, which pushes the smaller one into the spring, This piston then compresses air out a check valve.

When the pistons reach end of travel a valve flips. now compressed air pushes the smaller piston (Via a check valve) and the larger piston is vented. when the pistons then reach the other end of travel compressed air is again applied to the larger piston re-starting the cycle.

Max pressure is input pressure times the ratio of the surface areas of the pistons (Diamater squared would give the same ratio)

The thing would sound like a jack hammer.

As I said, I don't know anyone who makes one

[RVDude]

Air pressure boosters (not compressors) are somewhat common in the industrial world - they are also known as intensifiers and amplifiers. They can multiply pressures even in the 6:1 range. Do a google search "air pressure booster" and you'll get several hits. The issues in our applications are 2 fold. They are not cheap (a compressor being far cheaper) and they require a boat load of air (in cfm) to get a dribble (in terms of cfm) out.

[mrschwarz]

Originally Posted by wa8yxm

To do it you basically need two pistons, one large, one small, and some valves. Air pressure is applied via a valve to the larger piston, which pushes the smaller one into the spring, This piston then compresses air out a check valve.

I'm not an expert, but this sounds like an air-powered air compressor, to me.

[cb5300]

Somewhere I saw an ad for a "booster" that would hook up to my air connector in my bay and would give me around 180 PSI. I just can't find it now. I think it was around $500.00 for the hard mount.

[EngineerMike]

Chuck- You rig has a $20,000 air compressor (if you figure the cost of the engine that runs it) but it has a governor that trims the upper limit of air generated for the chassis. My ISL Cummins rig has the same setup as previous years, but due to a lot of customer demand, the mfgr set the governor to top out @ 135psi. I can air up my tires w/this setup. Not the fastest, but it works fine. Owners of earlier ISL's (or those w/lower max psi setting) can get the appropriate part from Cummins. I assume the same would be true for Cat applications.

Here is a thread w/discussion about the parts involved in upgrading the retained compressor output & some issues to watch.

Another option is to carry a CO2 tank like the Power Tank, along w/appropriate fittings. PT appears to do a good job of managing the exigencies of high volume air, and dealing w/the freezing effects of expanding CO2. They are not cheap to buy, but it is cheap once you own the gear to get refills, and you can get the tank refilled in most towns within a 3 day turn around. You can also buy just their regulator & get exchange tanks that make tank refill turn-around an over the counter process.

[RV Wizard]

If I were going to carry a tank, I would opt for nitrogen.

[Gary RVRoamer]

A pressure booster increases pressure at the expense of volume. If you get a 50% increase in pressure (a ratio of 3:2), you only get 2/3 the original air volume (cubic feet per second or cfs). And these onboard compressors don't have much air volume at 100 psi anyway. Still, it may be better than running at 100 psi when you really need 110.

I've never heard of one for an RV system and the industrial ones are pricey.

[EngineerMike]

Wiz- CO2 & N2 have their respective followings. From FAQs @ Powertank's site:
Q: Why CO2 instead of N2?
A: VOLUME. CO2 will give 3 times the power of N2 in a given tank volume.

I'm guessing w/the following CO2 has w/off roaders vs. N2 that there is some verifiable truth to that. I think it is has to do with CO2 compressing to a liquid (at which point you get lots of CO2, or N2, per unit volume) at a lower pressure (which lower pressure is still way higher than we use to fill tires or run air tools) than nitrogen. If you are using N2 to refill nitrogen shocks from time to time, N2 may be the better choice.

[RVDude]

CO2 messes with the ozone. It's a greenhouse gas. Whey add add more of it?
On that alone, I favor plain old air or N2 (76% of our air).

[Happycarz]

CB5300,
I too saw the ad for the booster. It was on page 103 in June issue of FMCA mag.
http://dickmantires.com/air_pressure/air_pressure.html

[TandW]

I refuse to stop breathing on the basis that I exhale a so-called greenhouse gas. Carbon and oxygen were placed here by the Master for Mother Nature to allocate to the air the seas or all the living things which will die, decay, fossilize and well, you get the picture. In my estimation the only way possible for humans to effect global warming is through the conversion of matter to energy in nuclear power stations. There is no reverse process for this in nature. Good luck!!

[EngineerMike]

Chief- I was going to point out how CO2 is condensed out of the atmosphere that we breathe for use in soda machines & beer dispensing, from which it goes back to the atmosphere, but I didn't want to appear as tho I was attacking somebody's religion.

I can see one good reason to go N2 vs. CO2- if you also use compressed gas to reload Nitrogen charged shocks on one of your toys, the w/N2 you have ample supply for that as well as using a blow gun or air impact tool.