Suppose I have a sump where water collects, and I want to pump this water out. The usual way is to immerse a pump in the sump with a float switch. When the float switch closes, the pump runs until it opens again. Simple.
But let's say I have a number of sumps, and I don't want to put a pump in each one. I can still fit the float switch to detect a full sump, to trigger a remote pump.
One scenario is I have one remote pump per sump, and the pump is connected directly to the sump inlet.
Another scenario is I have a single pump and some kind of valve gear to select which sump to drain based on the float switch status.
Is there a kind of pump that will work in these cases? In a regular sump pump, the float switch is arranged so that the inlet to the pump is full of water and so the pump doesn't need priming. But in the remote setup it's quite possible the tube from the sump to the pump contains air, and we want a pump that will suck out the air from the tube before the water will flow (the tube can be flexible if it helps).
Is this some kind of 'self priming' pump, or how would this be described?
The specific application I was thinking of was the condensate drains for air conditioners - typically they're mounted on the wall, and if it's not an external wall then you need to run the condensate drain up into the ceiling. 'Condensate pumps' exist, but they seem quite awkward to fit inside each unit and it would be easier and quieter to put a remote pump somewhere far away. The problem here is that the whole point is to pump each sump dry, so there will be air in the system regularly.
What kind of valve gear would be suitable for the one-pump-many-inputs scenario? Is there something that could automatically cut off inputs that have too much of a pressure drop (ie are pulling air not water)?
Or is this not going to work?
Thanks Theo