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JurekB
Slightly odd question...
(For an ecology experiment) I need to create a temporary airtight seal between two lengths of pipe with an external diameter of approximately 4 inches*. The seal does not need to be strong, just sufficient to prevent air seeping in for a period of a few minutes at close to atmospheric pressure, but it does need to be easy to attach and remove repeatedly.
My current idea is to use a length if inner tube as a sheath over the join. Do MTB/Fatbike inner tubes come in sizes that could be relatively easily stretched over such a pipe?
*Slightly longer explanation: The experiment, being conducted by my GF, is measuring soil respiration (gasses emitted from a known volume of soil in different environmental conditions). I mention joining two "lengths of pipe", one of these will be a length of 4in diameter plastic sewage pipe that has been sunk into the soil... there will be about 100 of these scattered around a forest and my GF needs to measure the gasses emitted from each one on a regular basis. The second "length of pipe" is actually a portable gas respirometer and is used to measure the gasses given off by the soil, it just so happens to be shaped a bit like a length of 4in diameter pipe. The gas respirometer will be carried around the forest to each section of sewage pipe where it will be placed on top of the pipe to measure the soil respiration. The respirometer is designed to work with c. 4in diameter pipe but the manufacturing tolerances on sewage pipes are such that the seal is usually pretty leaky so we just need a way to make doubly sure no extra air is getting in (and while portable, the gas respirometer isn't really designed for the messy tolerances of ecology experiments in the wild...). My simple suggestion is to cut a section of inner tube and slide it over the end of the gas respirometer and tape it in place, the inner tube could then be rolled up onto the respirometer and out of the way during transport, and then rolled down over the join between the respirometer and the pipe, creating a temporary seal while the machine is in use. Does this sound like a reasonable solution, or are there better alternatives? I have considered something a bit like this but the gas respirometer has some screws and other plastic knobbly bits on it's external surface that I imagine an inner tube would stretch over whereas I think this would not.
@mdcc_tester you usually have a pretty good eye for problem solving... any thoughts?