Basement Sink Drain Question

[ChrisC]

Hi everyone, looking for some advice. I want to install a pump out basement sink. I have attached a picture of my current drain situation at the basement laundry. The p trap is about 3 ft off floor and the top of the drain stack where the washer dumps is about 6 ft. This is the way it was built by the plumbers. I am trying to figure the best way to tap in the sink drain. I would use one of those vent-less sink pumps. I feel like it would be wrong to just pipe it in open to the top os the drain stack, i would worry about the sink over pumping that stack. Never happen with washer, but dont want to chance it. Thanks for any advice,should note the "sink" pipe coming in from above is from the kitchen
Chris

 

[ChrisC]

Was looking at this again, can I just tap a sanitary t in the vertical pipe from the sink above, and have the basement sink pump up to here? It should vent from above via the kitchen sink vent, right? ther is a check valve in the sink pump and also before the washer standpipe so nothing should back flow. Am i thinking about this correctly?

 

[Sponsor]

 

[Themp]

Normal sink drains are around 5 to 6 GPM. A washing machine is higher than that. So, pumping this into the same pipe as the washing machine should not be problem. I think you are making this more complex than it is.

 

[Cacher_Chick]

Is the basement sink draining into a basin that is pumped, or is it a direct pump? Any type of a pumped basin requires a separate vent.

 

[ChrisC]

https://www.homedepot.com/p/AquaPro-1-3-HP-Utility-Sink-Pump-55011-7/206852252

This is the pump I'm looking at. It says it's ventless.

 

[Cacher_Chick]

That is a direct pump, which does not require a separate vent. If that line is draining a sink above, your washer drain is not code-compliant as it needs to have a proper atmospheric vent to prevent the trap from siphoning.