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Technology / Re: Negate the expansion of freezing water using small, compressible balls

« on: 16/11/2015 16:35:38 »

I saw a device for use in pipes; you put a long plastic pipe inside the copper pipe, and then when the water freezes it squeezes down on the plastic and the copper pipe doesn't burst.

I don't see why in principle you couldn't do the same with a tank. Perhaps just putting some weighted fizzy drink bottles, or something similar, into the tank might stop it bursting.

I don't know that it's guaranteed to work though; it may critically depend on how the crystal structure forms each time as to whether it pushes on the plastic bottles or on the sides- ice shove is quit an impressively powerful phenomena.

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Technology / Re: Negate the expansion of freezing water using small, compressible balls

« on: 12/11/2015 22:31:52 »

We do this to absorb the thermal expansion of oil in x-ray tube assemblies. The "absorber" is a small rubber bellows or ball filled with nitrogen that compresses as the oil expands.

This might work in principle with freezing water but you might need several balls as the water will freeze from the top downwards and thus trap a floating ball.

Alternatively put the water in a flexible bag inside a metal or glass bottle.