Battery backup Sump pump installation

[luhem519]

Hi guys,

I am planning to install secondary battery back up sump pump but I was not how to set up check valves location. I already have one check valves shown in the picture. Do I need two separate check valves for both pumps? if so where would the be installed?
Thanks,

 

[Reach4]

Yes. As in your sketch.

 

[Sponsor]

 

[luhem519]

Reach4, Should I remove the existing check valve there? Can I replace it with Flexible PVC coupling shown below? Thanks!

What should be the distance of new check vales from the sump pump?

Flexible PVC coupling:
https://www.homedepot.com/p/Fernco-1-1-2-in-x-1-1-2-in-DWV-Flexible-PVC-Coupling-P1056-150/100058870

I' m thinking it will look like this.