I finally realize that I need a battery powered back up sump pump, and finally have time to install it.
I want to use 2 check valves and then combine the output into the existing output pipe.
1) I'm not sure I will be able to do all the piping within the sump: The sump came with a perfect plastic plug that has room for the pedestal pump, the float rod, and the output pipe, but no room for anything more, no room for another pipe, and the plug is such that the notch in it can't be enlarged or the plug will fail, collapse or something. So I want to do the connections inside the sump. And have only one output pipe like it is now.The sump is 17 inches in diameter and there is room on the floor of the sump for both the old pump and the new one.
The sump is 18 inches deep. Is that likely to be enough?
2) Is it a mistake to do it this way? Should I put a second output pipe in parallel with the current one, at least until I get out of the house? Once in 27 years there was so much water coming into the sump that my 1/2? HP pedestal pump wasn't enough to expel it all, and the sump overflowed.The battery operated pump will run at the same time the AC pump runs, but maybe the standard diameter output pipe will restrict the output so that the total won't be much more than the one pump does now. Should I put a second output pipe in parallel with the current one?
Thanks.