How can I stop water flow in a hose after a certain water level?

Question

I have a bucket that I want to fill with water only up to a certain level, the bucket is indoors, the first thing I thought of was a siphon like the one in a toilet but would prefer a smaller mechanism. I am not very well versed in these things, so is there something that I can affix to a hose which will stop the water flowing past a certain level?

Answer 1

Try and get ahold of a gasoline pump handle, a so-called "fill nozzle". Those shutoff when enough of the nozzle becomes submerged. Uses a clever mechanism of air pressure and levers so no electronic sensors required. Can even be locked open so you don't have to be there. What more could you ask for?

The moving gasoline produces a venturi effect that sucks in air through a narrow channel that runs along the water nozzle. So long as this air channel remains unobstructed (for example, by gasoline plugging it because the gasoline level has risen high enough), it causes a pressure change on a membrane against atmospheric pressure that is coupled to a spring loaded latch.

This spring loaded latch, the hand lever, and the valve that allows gasoline to flow are all coupled to the same lever at three different points, respectively. The fulcrum of this lever is actually the spring loaded latch and it serves to anchor the lever so the hand lever can pull open the gasoline valve. However, when the air channel is blocked off, the pressure on both sides of the membrane are such that the spring loaded valve cannot properly latch. No latching means the fulcrum isn't anchored at any point which means the entire lever is floating and the hand lever has no leverage to pull the gasoline valve open.

https://www.youtube.com/watch?v=fT2KhJ8W-Kg

Answer 2

The toilet siphon does two jobs:

• When the handle is pushed a valve lifts a large volume of water to fill the siphon and drain the cistern quickly through siphon action.
• It also provides a safety function: normally the ball-valve should shut off the water before it reaches the siphon overflow level. If the ball valve is not set correctly or fails completeley then the siphon just acts as an overflow (and in this case it won't start the siphon action and drain the tank).

Options:

• The overflow solution wastes water but is quite fail-safe.
• The ball-valve solution is more efficient and is cheap - but maybe not in bucket size.

I would use both a ball-valve for water efficiency and an overflow for safety.