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Water Pressure in a vessel

  1. Feb 6, 2016 #1
    Hi there all physics geniuses. I come looking for help. I need to create water pressure in a vessel in the easiest possible way. And not by using a standard manual pump to pump in air.

    I've come up with a syringe-spring type system but it's flawed as the spring will rust...

    Also I've thought of forcing water into a chamber through a one way valve using a piston similar to that of a syringe.

    Does anyone have any other ideas?

  2. jcsd
  3. Feb 6, 2016 #2
    How big is this thing, and what is its shape? Is there only water in it, or is there gas too?
  4. Feb 6, 2016 #3
    It's only water, and I need to be able to pressurize a litre of water so that it will spray out of the container rather than just flow out. The container could be any size and shape...
  5. Feb 6, 2016 #4
    Put a lot more water on top of that 1 liter in a very tall container. The weight of the column of water will create pressure at the bottom. You'll get about 1 Kpa per decimeter of water column height.
  6. Feb 6, 2016 #5
    I forgot to mention, I need the maximum size of the container to be 2 litres, so that won't work for me, but thanks for the reply!
  7. Feb 6, 2016 #6
    It sounds like you would like to have a very constant flow rate. If so, then Google Positive Displacement Pumps.

  8. Feb 7, 2016 #7


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    How much of the 1L must spray out? Could you just fill it with very cold water, seal it, and allow it to warm up?
  9. Feb 7, 2016 #8


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    Use the water to inflate a balloon? Perhaps two balloons one inside the other to increase pressure?
  10. Feb 7, 2016 #9


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    I'm not sure I understand what you're trying to do here. If you have only water in the container, you'll never be able to compress it enough to make a significant amount flow out when released. It's almost like saying you want to compress a steel bar so that when released it will expand to double the length.
    IMO the only way you will achieve what you say you want, is either to introduce some gas into the container, maybe by not filling the container with water, maybe by dissolving the gas in the water, or by introducing some compressible object such as a balloon, or making the container variable in size.
    If you are introducing compressed gas into the container, why would you say both, you want the simplest way and you don't want to use a pump, which is probably the easiest way?

    If you don't need to pressurise the container and intend to force the water out using a syringe or similar, perhaps you don't need to give up on that idea yet. I have some plastic springs (I have no idea what material) which I don't think would ever rust. I also have syringes which don't have any sort of spring, so would also not have a problem with rust.
    My own favourite pump for high pressure low flow, is the gear pump, which has a very controllable flow.
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