Technical question regarding air compressors

SavageUrge · **Posted:** Fri Jun 09, 2006 12:26 pm

Can anyone tell me why an air compressor like THIS
or a Viair won't air up an air mattress directly, however it will inflate a tire to 45 psi? I imagine it has something to do with High Pressure / Low Volume or vice-versa, but an air mattress doesn't inflate to that high a psi does it? I would think a mattress would only be inflated to about 20psi max. If anyone can show me an equation so I can figure this one out, or explain it, it would be greatly appreciated! Thanks everyone!

Se7enLC · **Posted:** Fri Jun 09, 2006 1:13 pm

SavageUrge wrote:

Can anyone tell me why an air compressor like THIS
or a Viair won't air up an air mattress directly, however it will inflate a tire to 45 psi? I imagine it has something to do with High Pressure / Low Volume or vice-versa, but an air mattress doesn't inflate to that high a psi does it? I would think a mattress would only be inflated to about 20psi max. If anyone can show me an equation so I can figure this one out, or explain it, it would be greatly appreciated! Thanks everyone!

Where did you see that you can't inflate an air mattress with that? I couldn't find any warning like that on the site you linked.

The only time I've seen compressors say "not for use with air mattresses" is with those zero-volume emergency air compressors that plug into the cigarette lighter and just compress air right out of the....air..... for pumping up a flat tire. I assume the warning is because to pump that much volume, you'd have to run the compressor constantly for a long time, which they aren't designed to do.

silver_2000_tj · **Joined:** Sat Jan 07, 2006 12:17 pm **Posts:** 29

That little compressor is amazing, I have one mounted under the hood of my Jeep and it's simply amazing. I paid 49.00 at Pep Boys for it and it's quick. I was looking for a compressor and saw a comparison between 7 to 10 of the top compressor and this little 50.00 compressor was in the top 2 or 3. Let me know if you have any other questions. It also comes with a small accessory pack that will allow you to air up toys and other items, I don't see why you can air up a mattress with it.

jason thompson · **Posted:** Fri Jun 09, 2006 3:48 pm

silver_2000_tj wrote:

That little compressor is amazing, I have one mounted under the hood of my Jeep and it's simply amazing. I paid 49.00 at Pep Boys for it and it's quick. I was looking for a compressor and saw a comparison between 7 to 10 of the top compressor and this little 50.00 compressor was in the top 2 or 3. Let me know if you have any other questions. It also comes with a small accessory pack that will allow you to air up toys and other items, I don't see why you can air up a mattress with it.

you may want to reconsider your mounting or get a check valve between the out let and the compressor head that open end male fitting is going to let any water and moisrure right in to the head and it will not last long at all

i had it happen to mine and it was in the cab behind the rear seat of my TJ bought the same one again and did it up right with a tank a 120 off 90 on swich a small tank that is about 5 or 6 gal and it will run a 1/2" impact in short burst but good enough to change a tire

silver_2000_tj · **Joined:** Sat Jan 07, 2006 12:17 pm **Posts:** 29

I have a plasic cover that goes onver the fitting, I took the cover off to take the photo.

CaKJFreedom · **Posted:** Fri Jun 09, 2006 6:27 pm

I have one of those. $25 from Kragen. Exact same one. It takes around 4-5 minutes to get an mtr from 20-38.5. Blew up air mattresses and a 3 or 4 person boat too, but it took a long time.

Just wondering or do you have one that doesn't work right?

silver_2000_tj · **Joined:** Sat Jan 07, 2006 12:17 pm **Posts:** 29

Here check this out!
http://gearinstalls.com/pepboys.htm

the link where they put the top compressors head to head
http://www.parksoffroad.com/prodreview/inflatortest/inflatormain.htm

Taz · **Posted:** Fri Jun 09, 2006 8:59 pm

I'm guessing the issue is the max continuous duty cycle. If you are looking at a camping air mattress they are pretty large volume to fill. Depending on the mattress and the cfm of the compressor you may get to the max duty cycle which looks like about 40 minutes at low pressure.

Jeepjeepster · **Posted:** Fri Jun 09, 2006 10:51 pm

Theres no way an air mattress is 20psi, more like 5psi.

SavageUrge · **Posted:** Sat Jun 10, 2006 5:30 am

I was reading another Jeep forum somewhere (can't find it now), but they all said that they ended up sleeping on the ground when they tried airing up a mattress with a unit of this design and similar power - I was a bit confused on the subject myself, but then again my technical expertise on air flow pressure and volume is not really up to snuff. Still confused I guess - thanks for any additional input. BTW this compressor is $59.99 at my local Pep Boys, if anyone is interested. You'll find a LOT of info on this unit online if you look up Masterflow MV-50. Every site I found had nothing but positive reviews for this compressor amongst all the 4x4 clubs!

Jeepjeepster · **Posted:** Sat Jun 10, 2006 10:24 am

SavageUrge wrote:

I was reading another Jeep forum somewhere (can't find it now), but they all said that they ended up sleeping on the ground when they tried airing up a mattress with a unit of this design and similar power - I was a bit confused on the subject myself, but then again my technical expertise on air flow pressure and volume is not really up to snuff. Still confused I guess - thanks for any additional input. BTW this compressor is $59.99 at my local Pep Boys, if anyone is interested. You'll find a LOT of info on this unit online if you look up Masterflow MV-50. Every site I found had nothing but positive reviews for this compressor amongst all the 4x4 clubs!

Its really simple. Think of it as a water hose. If the hose is really small, it can still have tons of pressure but will not fill up a pool in a hurry. The water hose can also be huge but not have any pressure at all, which would be good to fill up a pool. Get it? :wink:

Edit: Since alot of us cannot get these where we live, wonder if anyone could find the ones on sale and be cool enough to ship them to us? Some people are talking about getting them for $25, and then some are $70. Would be a cool thing to do for fellow jeeper!

SavageUrge · **Posted:** Tue Jun 13, 2006 12:21 am

Hey Jeepjeepster, from all the research I've done on this compressor, I've come to the conclusion that they are no longer available for $25 unfortunately. The lowest price I have seen them is online at PartsAmerica.com for $41.99, however, the website says they are no longer available. My local Pep Boys has them for $59.99 so check it out there if you don't have a Checker, Kragen, or other big name auto staore around you.

Technical question regarding air compressors

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