Adding laundry drain -- where?

We are adding a laundry room. I am trying to figure out how best to attach the drain to the existing convoluted plumbing. Hopefully my drawing is clear. The slope in the 4" lines is minimal.

Is it OK to attach as I have pictured it? Basically with a wye at any convenient spot in the 4" drain, or is there more to it?


Second drawing shows the plan for the standpipe/trap/vent. From my reading here, I feel pretty comfortable with this part (but please advise if I am missing something!)


Chris

The laundry only needs to be 2", and if that pipe from the bath is really 4", you can tie in there.

In the elevation drawing, the fitting is wrong where the vent connects. Looks like a heel inlet elbow, and you would have an S trap. Change that to a 2 X 1½ x 2 sanitary tee.

A "heel inlet" 1/4 bend IS a sanitary tee of sorts. It is what happens when you make a 3x2x3 sanitary tee. If his piping is 2" and 1 1/2" then it will be a sanitary tee regardless of how it is drawn, and if it is 3" and 2", then he should have 3x2 tee with a cleanout and bushing on top of it. Unless that is the easiest path to open the floor, he does not have to go that far downstream to make his connection. He can go directly to the main line at a 90 degree angle to the pipe. IF that is an accurate representation of how the pipe runs, then I would have done a "field sobriety test" on the installing plumber.

Thanks for the reples.

RE 3in pipe: Oops! Not sure where I got the idea I needed 3in pipe. I will use 2in.
RE the vent connection: I will use a 2x1.5x2 sanitary tee.
RE the main line connection: It is a 4in pipe, so I will connect at 90 degrees.
RE the drunk plumber: Yeah, its a mess. I have spent a good number of hours under the house fixing issues. We are having a problem with clogs in the main line outside the house where it bends around towards the septic. I think eventually we will have to start over from scratch, configuring the main line with a more direct path to the septic.