Cold Temperature Storage of Inflatable Dinghys

Donald Tyson":1m3sh4qc said:
Pretty sure you meant the other way around. Thoughts?

ssobol":1m3sh4qc said:
Donald Tyson":1m3sh4qc said:
Is altitude an issue for these boats. Does the pressure change enough btwn Donner Pass and Sacramento warrant deflating them before descending. Somewhere in the middle here my the suction cups of my EZPass often let go. And tires change pressure. Doe this threaten an inflatable.

More important to let out a little air before ascending. Going down isn't a problem.

External air pressure increases as you descend. This increases pressure on the outside of the tube, decreasing the pressure difference between the pressure inside the tube and the outside.

As you ascend, the outside air pressure decreases, so the pressure differential increases.

RIB and SIB tubes are designed for a certain pressure difference between the inside and outside air pressures. When you inflate a tube you are increasing the pressure X amount above ambient pressure (in the case of a RIB about 1.5 psi, a SIB is about 3 psi).

If you inflate a tube and then increase its altitude (or reduce the ambient air pressure), it will eventually burst. This can happen with any pressurized object if the pressure differential exceeds its strength.

If you pump up an inflatable at a high altitude to normal working pressure (i.e. some amount above ambient) and then take it to a lower altitude, the pressure differential will decrease and the tubes will get soft.

While SIBs and RIBs seem like they are very rigid when inflated, it doesn't take very much pressure above ambient to accomplish this. This is a benefit of large volume. Smaller things like inflatable SUPs and kayaks need a higher pressure because the volume is a lot less. I have an inflatable kayak that needs 15 psi (above ambient) to be inflated properly. But the acceptable pressure range is also greater.
 
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