Ballast rim guard and proper inflation

[ovrszd]

No definitive answer. But I'd say 5psi is pushing your luck.

 

[Texasmark]

No definitive answer. But I'd say 5psi is pushing your luck.

True and with that in mind, I consider where, when and what I am doing with that pressure. For odd jobs around the place it works fine. If I am going to change things, like load up an implement, then the pressure gets adjusted upwards accordingly for the duration.

 

[Todd727]

It doesn't matter if the air is hot or cold, high pressure or low pressure, the air itself has close to no strength to support anything. If air could support stuff, things wouldn't fall if you drop them. What pressurized air can do is exert pressure equally in every direction. Inside a tire and wheel assembly, pressurized air is doing just that. It it pushes against the tire, the rim and everything it touches with equal force in every direction. It pushes up, & down, (against both the tire and the wheel) and every version of sideways. The more pressure, the more force. As the pressure is increased, the tire itself becomes so rigid that it can't flex because of that pressure pushing against these surfaces. The tire becomes so rigid it will support a vehicle without collapsing.
Another way to look at it is that the compressed air is pushing upward against the wheel with the same force that it is pushing downward against the tire/ground contact point. If that up/down force created by that air pressure exceeds the downward force exerted by the vehicle due to gravity, and the sidewalls have enough rigidity to not fail, the vehicle isn't going to sink toward the ground.

Air has far more "strength" than you imagine. If it didn't, we wouldn't worry about wind resistance, engineering for wind loads or traveling by air. Air behaves as a fluid.

You say the air has no strength and then go on to explain exactly how much strength it has when contained withing a flexible body under pressure. The same holds true for a rigid container. If it didn't there would be no danger from a catastrophic rupture of an air tank.

Air is supports a tire. If that were not true, and the strength came solely from the sidewall, there would be no need to add air to a tire and flat tires would not exist. We measure the force that air exerts in a variety of ways, PSI, hPa, BAR, etc.

 

[Billrog]

An example of the power air has just take a sealed container from inside and set it out in the cold or in a fridge.

 

[ovrszd]

In my uneducated pea sized brain, the three most powerful things in this World are Air, Cold, Heat. Not necessarily in that order.

 

[rd_macgregor]

When I backed out the stem and arbitrarily let it all out, the tire immediately collapsed with the weight of the fluid and mixture came gushing out the sides of the tire.

I'm glad I saw this comment. I have a loaded rear tire with a slow leak. The last time I re-aired the tire, I noticed that fluid was slowly bubbling out of the stem. To me, this means that the stem core is not sealing properly. I was going to jack up that side in the rear and screw out the stem to replace it, but your comment suggests I could end up with a big mess (and one unloaded tire!) if I do this.
Is the only solution to remove the fluid, do the stem replacement, then refill??

 

[dadster4]

Then what exactly are you adding to the tire to increase it's pressure?

If this were true, we also wouldn't gain anything by having our welding gas tanks at 2200psi or scuba tanks at 3000psi.

Too many people confusing volume with pressure. A scuba tank with no pressure has the same volume as the same tank pressurized to 3000 psi.

 

[ovrszd]

Too many people confusing volume with pressure. A scuba tank with no pressure has the same volume as the same tank pressurized to 3000 psi.

Cubic Inches of internal space, yes. Cubic Inches of atmospheric pressure air, no.

 

[jonsstihl]

you are correct but by making that statement you are removing the pressure aspect of it. Of course there is more air molecules in the tank at 3000 psi than at atmospheric pressure. that is why the pressure is higher if it had the same amount of Cubic Inches of atmospheric pressure air the pressure would be 14.7 psi not 3000. I think we are all saying the same thing just not in the same units of measurement. I have to admit this is the first time I have ever heard of volume described as Cubic Inches of atmospheric pressure air.

 

[4570Man]

An example of the power air has just take a sealed container from inside and set it out in the cold or in a fridge.

Anyone see where Mythbusters imploded a 55 gallon barrel and nearly a train car using this method. They did get the train car to implode, but they had to dent it first. The train car was 1/2 steel.