I need to install a pump for a kitchen sink drain line (1 1/2") in the basement. The outlet line runs horizontal with 5 1/2" drop over 44' to a macerating pump that then sends it up and out to the septic. The achieved slope (1/8" per ft) does not meet code for the pipe size (1/4" per ft). Therefore a pump is the solution. I have the pump and my question is if a check valve is required. The sink will be the only fixture draining on that line. If the check valve is required do I have to put it vertically and above the outlet port on the pump? Or can I place it horizontally within 25 ft of the pump?