Hello all, I am planning out a relocation of my washing machine and laundry sink in the basement. They will be moved across a room to the opposite wall about 20' away. I am familiar with basic installation techniques, cutting and joining pipe, etc, but I do not have the knowledge to decide what size pipe to use, which fittings, and so on. Any advice is appreciated!

See diagram:



Some questions I have:
-is the plan permissible as shown in the diagram?
-what size pipe to use for drain portion and vent portion?
-what fittings to use - I assume sanitary tees for connecting to old vent, and wye + 1/8 turn for connecting to the new drain line?
-is the dotted vent branch necessary?
-anything I might be missing?

Any other constructive comments are welcome. Thanks in advance for your help. I am happy to provide any other information that might be needed.

1. No
2. 2" for the drain and 1 1/2" for the vent.
3. Right , use an inverted tee to tie the new vent in with the old one.
4. No.
5. You need to use a wye and 1/8 bend downstream to vent the washer trap, and use a tee in the vertical portion of the vent to catch your sink drain.
The standpipe out of the trap needs to be at least 24" tall, the inlet to the standpipe needs to be at least 34" from the floor.