tubes pressure / temp variation

[Erin]

Originally Posted by malthouse

You should see the effect of a few drops of homebrew on pressure fluctuations!

Are you suggesting side effects?

Would atmos pressure at 900mb causing relative tube pressure to increase be cancelled out by temp reduction as the temp normally falls when we have low pressure systems over us? Or am I torking more bollix than the other two put together?

[biffer]

Originally Posted by Erin

Are you suggesting side effects?

Would atmos pressure at 900mb causing relative tube pressure to increase be cancelled out by temp reduction as the temp normally falls when we have low pressure systems over us? Or am I torking more bollix than the other two put together?

i reckon you got a Phd in torkin bollox

[chewy]

Originally Posted by Erin

Are you suggesting side effects?

Would atmos pressure at 900mb causing relative tube pressure to increase be cancelled out by temp reduction as the temp normally falls when we have low pressure systems over us? Or am I torking more bollix than the other two put together?

It would all depend on what the original air pressure was inside the tubes and the atmospheric pressure before the increase or drop to 900mb and what the actual drop in ambient temperature was, its all relevant.

[Courageous]

........ Oh what have you started????

[chewy]

Originally Posted by Courageous

........ Oh what have you started????

If we had an inflatable in one of your aircraft and the cabin was pressurised how would this affect the tubes?

[Courageous]

Originally Posted by chewy

If we had an inflatable in one of your aircraft and the cabin was pressurised how would this affect the tubes?

Oh I hate these..... it's a bit like the weight of the pigeon flying in the aircraft isn't it? You know this already Chewy you rascal and so it's a trick question isn't it? It depends on the pressure we take her (or boeing takes her to) of course as it's all about pressure differential Inside to outside of the tibe isn't it? Effectively the aircarft becomes the atmosphere.

FWIW at max operating altitude of 41000ft we hold the cabin altitude at 8000ft and the pressure differential is close to 9psi.......

Some guys insist on deflating the kids footballs as the 5psi increase in pressure might burst them.

Poor kids.....

[chewy]

Originally Posted by Courageous

Oh I hate these..... it's a bit like the weight of the pigeon flying in the aircraft isn't it? You know this already Chewy you rascal and so it's a trick question isn't it? It depends on the pressure we take her (or boeing takes her to) of course as it's all about pressure differential Inside to outside of the tibe isn't it? Effectively the aircarft becomes the atmosphere.

FWIW at max operating altitude of 41000ft we hold the cabin altitude at 8000ft and the pressure differential is close to 9psi.......

Some guys insist on deflating the kids footballs as the 5psi increase in pressure might burst them.

Poor kids.....

But you'll have two differential pressure, the one between the atmosphere and the pressurised cabin and then the one between the cabin and the tubes, oh are we working gauge or absolute?

[Stephen-RIB]

Thanks chaps, all I need to do now is give him the tinyurl of this thread!

Cheers

[Courageous]

tinyurl? Don't do that! Then he'll be too klever for his own good........

[RRIBS]

Originally Posted by malthouse

Sell him an automatic compressor and fit him pressure relief valves. The tubes will always be perfect and no need to worry about any of that science stuff.

Any recommendations of a suitable compressor and valves?

[boristhebold]

The mathematical principles are described in Charles law, jaques Charles 1790, he can look it up. Basically as we all know the pressure,volume,density changes with temperature, jaquesnworked it out when looking at early balloons, and produced a formula to describe it.

The pressure difference in my tubes can be very noticeable this time of year due to late afternoon chill factor.