TargetTalk

hi,

I have one pardini cylinder, 250 bar can it be filled by the cycle shops( they got big tank) or petrol pump car inflator?

yours sincerley

250 bar is over 3500psi.

I doubt whether any car or cycle tyre inflators will go much over 100psi (if that).

David Levene wrote: ↑Sun Sep 22, 2019 12:50 am 250 bar is over 3500psi.

I doubt whether any car or cycle tyre inflators will go much over 100psi (if that).

i was talking about those which are iinstalled at petrol pump and cycle vendors.( the big tank u might have seen)

rajemessage wrote: ↑Sun Sep 22, 2019 1:19 am

David Levene wrote: ↑Sun Sep 22, 2019 12:50 am 250 bar is over 3500psi.

I doubt whether any car or cycle tyre inflators will go much over 100psi (if that).

i was talking about those which are iinstalled at petrol pump and cycle vendors.( the big tank u might have seen)

I know what you are talking about. Why don't you ask them?

> i was talking about those which are installed at petrol pump and cycle vendors.( the big tank u might have seen)

The size of the tank makes no difference. There is no reason they would keep air at such a high pressure.
If cost is your problem, get a manual pump. They are inexpensive and work quite well (besides being a tool to exercise).

The simple and truthful answer is NO

rajemessage wrote: ↑Sun Sep 22, 2019 12:17 am hi,

I have one pardini cylinder, 250 bar can it be filled by the cycle shops( they got big tank) or petrol pump car inflator?

yours sincerley

Oh dear........time for a Physics lesson.
1 bar is equal to 1 atmosphere of pressure or 14.7 lbs/sq.inch (approx).
A Spray gun uses 4-6 psi or 0.3-0.4 bar.
A Car tyre is inflated to typical 28-32 psi or 2 bar (approx).
Most workshop compressors are 150 psi or 10 bar. (Medium to high output volume).
A 747 wheel is inflated to approx 200 psi. or 14 bar.
Scuba tanks are either 200 bar or 300 bar high pressure.
High pressure Scuba compressors are 4500 psi or 300 bar (Low output volume).
Minimum pressure for a Pardini pressure regulator to work, about 1100 psi or 80 bar (tank considered empty).
High pressure hand pump.........hard work.
So answer.........NO

Even if they were using scuba type tanks to store the air it is highly unlikely (dangerous) that they would by filling car or cycle tyres without regulating it down to a much lower pressure than is requied for air guns.

I get the impression from the question and the follow-up question from rajemessage that a more fundamental misunderstanding is at work. Namely, the impression that air pressure building to 250bar is an additive problem much the way one might stack 250 bricks.

If this is what's happening, then I'd suggest trying to visualize filling a suitcase with clothing. If you fill a suitcase to the point where you can just barely close the lid, sitting on it to be able to lock the catches, that suitcase is now truly 'full.'

Now imagine a pile of neatly folded clothing which covers an entire king-sized bed, stacked to the ceiling - thousands of articles of clothing, many times larger than the suitcase capacity. Having all those clothes piled up does not in any way increase the ability of the suitcase to hold them. You would need to compress the clothing such that their fibres were interlocked to the point of destroying the cloth, breaking everything down until it was many times smaller than in its normal folded state. It is unlikely you could wear such clothes again, but perhaps if you had a strong enough, large enough hydraulic press you might be able to get those clothes small enough to fit into the suitcase.

That is much like the compressed air question at hand. A fundamental difference of course being that the spaces between atoms and molecules of air are rather large, allowing for a 'springy' quality of air which enables considerable compression without damage to those particles. But the strength of the press is still required. Hence the stepped-up pressure mechanisms of whatever sort of pump, forcing air into smaller and smaller format such that a lot more of it can fit into an airgun cylinder. No gas station pump would be designed to come remotely close to such pressures, as no tire has ever needed nearly that sort of pressure, in fact any tire ever made would explode at less than 1/10th the pressure used in an airgun. That's part of why we don't have rubber airgun cylinders. A filled airgun cylinder has equivalent energy when filled to a fragmentation grenade. Fortunately (unless it fails due to inadequate manufacturing or material specifications) that energy is released only a small amount at a time as we shoot.

"i was talking about those which are iinstalled at petrol pump and cycle vendors.( the big tank u might have seen)"

If you place that large tank in an appropriate hydraulic press, you can squeeze it down and raise the pressure to 250 bar. Some of you people are really letting science get in the way. I have it on good authority that PV=nRT only applies if you choose to let it.

cute. boom.

rajemessage, are you confusing BAR and PSI? There are industrial / commercial air compressors like you would see in a factory or automotive shop, that will pump to 250 PSI. But not BAR.

Most air compressors in Automobile repair shops go to 125 PSI, or something close.

125 psi = 8.61845 BAR. 1 BAR is 1 times atmospheric pressure

SO, for an approximate result, divide the PSI pressure value by 14.504 to get BAR

Since you need to get over 100 BAR to get the gun to function well, you can see that an Automotive Compressor will be insufficient to do the job.

Mike38 wrote: ↑Wed Sep 25, 2019 5:47 pm rajemessage, are you confusing BAR and PSI?

Let's not confuse the poor man.
Here are a couple of conversions to help.....
250 Bar equals =
25,000,000 N/m2 Newton/sq.metre
3,626 psi Pounds/sq.inch
18,751 kn/m2 Centimetre of Mercury
250,000 hPa Hectopascal
7,382.5 inHg inchs of Mercury
522,135 lb/ft2 Pounds/sq.ft
Which ever way you cut it, its a lot...

Simple answer:

No, tire shop compressors max at 150 PSI. Air cylinder in gun is 2,000 - 3,000 PSI.