Through my understanding of water and plumbing, water has a pressure behind it. But how is it that water can be held back under pressure in a hose and it not burst a pipe or the hose?
In: Physics
The pressure in your waterlines is set by your municipal water system or (if you are on a well) your well pump. These are usually set somewhere in the 35 to 100 pounds per square inch (psi) range, so once your pipe or hose pushes back with the same pressure the pressure stops building.
I mean there’s no real secret behind this. It’s just a question of magnitude.
Pressure doesn’t just “build up”. Yes it is always there and yes if the pipes were reaaaally fragile (which they typically aren’t) it could technically burst them but we simply don’t need that much pressure on our water supply to a point where that would become a problem.
That being said, if the water freezes inside the pipes that often does burst them.
Water is piped in similar to electricity. A main water lines has a lot of pressure because *insert number* of houses are using it, when that main line is branched, they can install a pressure regulator that only allows…1000 psi (a guess) for that brand based on that neighborhood. Each brand after that may be 200 for a few houses. Either before or after your personal water tap is a pressure regulator that is regulating pressure to your home to 50 PSI.
With power lines, some may be 500,000 volts. By the time is it ran through *insert number* of transformers, it’s only 240 volts.
Pipe/hose is made to hold the water pressure.
Household water pressure is only 40-60psi usually. 1/2” diameter Schedule 40 pvc pipe (the smallest cheapest stuff you can get at the hardware store) is still rated for 600psi.
Garden hose is usually rated for about 90psi.
The water pressure from your pipes is pushing on all the water in the hose. But after a while, the pressure in the hose water is the same as the pressure coming from your pipes. The pressure can’t get any higher than that, because to make the pressure higher you have to push water in harder.
So the hose is made to withstand the normal pressure of most water systems. That way when it’s fully pressurized, it won’t burst.
The water going to your hose from say, a tap isn’t strong enough.
Stick that hose onto an industrial water pump and seal the open successfully and you’ve got what you asked for
Your water supply will be pressurised to a certain maximum amount, and should never go above this pressure – this means that once the water in your pipes reach this point, the pressure won’t keep on building and get higher, it just stops at the supply pressure.
And the simple reason why your pipes, hoses and other fittings don’t burst is that they are designed to resist this pressure. When they make a hose they choose how strong it will be based on things like the materials used, the thickness and so on. Make a really flimsy, lightweight hose and it might burst at a normal mains supply, make a really strong equivalent and it may be capable to hold many, many times the pressures it will actually experience. In reality most hoses and fitting will be somewhere in the middle – capable of holding a lot more pressure than they need (to cover people misusing them, faults, etc), but not so overbuilt as to be too expensive.
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