Septic lift plumbing

[Jlong]

I’m rerouting plumbing from upstairs and will have isolated 6 foot horizontal run of septic lift liquid. Currently feeds into 4 inch line that has upstream feed from frequently used fixtures. Question is do I maintain 4 inch line or can I run 2 inch for that segment. Basement used few times a year. 

[Jim Katen]

1 hour ago, Jlong said:

I’m rerouting plumbing from upstairs and will have isolated 6 foot horizontal run of septic lift liquid. Currently feeds into 4 inch line that has upstream feed from frequently used fixtures. Question is do I maintain 4 inch line or can I run 2 inch for that segment. Basement used few times a year. 

What fixtures will use this section of drainpipe? 

[Jlong]

Kitchen sink, shower, bathroom sink, toilet. Hardly ever used. Thx for quick reply. 

[hausdok]

Hi,

I'm not a plumber, but I've seen a lot of these setups where basements have been remodeled with a new basement bath. Typically a two-inch line runs from the lift pump up to the underside of the floor joists above (or through them if ceiling height is an issue) and then down into the topside of the main. Make sure that you vent the setup properly according to your local code. Do that and you'll probably be fine.

ONE TEAM - ONE FIGHT!!!

Mike

 

 

[Jim Katen]

The plumbing code leaves this pipe size up to the pump manufacturer. Given that you're only dealing with 8 fixture units, I can't imagine that the pump manufacturer would require anything larger than 2". 

If you're doing this under a permit, get the pump model number and ask the manufacturer to give you a discharge pipe size for the local inspector. 

Be sure to join the 4" pipe from the top, like Mike said. 

[Ben Davis]

The plumbing code leaves this pipe size up to the pump manufacturer. Given that you're only dealing with 8 fixture units, I can't imagine that the pump manufacturer would require anything larger than 2". 

If you're doing this under a permit, get the pump model number and ask the manufacturer to give you a discharge pipe size for the local inspector. 

Be sure to join the 4" pipe from the top, like Mike said. 

And when you connect to the pipe from above, see that there is no twisting