Joined
·
174 Posts
I think I'm missing something about check valves. I understand how the valve itself works, but I'm not understanding why or when they are required. If I put one end of a tube in the tank (let's say it's connected to a sponge filter) and the other end on the floor, I could wait 10 years and it will never start a siphon. If I put an air pump on the floor end and let it run till it bubbles in the tank, I can take the hose off and put it back on endlessly without ever starting a siphon. So what I'm trying to figure out is what conditions are necessary to allow an air line on an air pump to start siphoning water from the tank.
I know it sounds silly, but I'm asking honestly. I feel like I'm back in high school and struggling to get a passing grade in physics. Under what "real world" conditions does an air line slipping off a pump (or the pump failing) will it start to siphon water from the tank? I feel like I could set up an experiment in a lab using altered pressure gradients to make it happen, but those conditions would never be naturally created in the living room. Short of sucking on the floor end of the airline to intentionally fill it with water to start a siphon, I can't make it work.
FWIW, I use check valves. But I really don't understand what has to happen for there to be a problem they can prevent.
I know it sounds silly, but I'm asking honestly. I feel like I'm back in high school and struggling to get a passing grade in physics. Under what "real world" conditions does an air line slipping off a pump (or the pump failing) will it start to siphon water from the tank? I feel like I could set up an experiment in a lab using altered pressure gradients to make it happen, but those conditions would never be naturally created in the living room. Short of sucking on the floor end of the airline to intentionally fill it with water to start a siphon, I can't make it work.
FWIW, I use check valves. But I really don't understand what has to happen for there to be a problem they can prevent.