You can use a fixture cross at the same height and use the one vent.
Not a san cross. What you have now is a SanTee.
A double santee wouldn't work. I would need a double fixture fitting.
I posted this question at the end of a very old thread (http://www.terrylove.com/forums/show...ht=#post277172) and didn't receive a response, I have an existing standpipe for my washing machine going into a 2" drain vented above with 2". The washing machine drain comes from the left in my picture.
I would like to add a laundry sink to this drain. My question is Washington Code specific as I live in Washington. Can I simply add a cross T where the washing machine enters this stack and drain both the sink and washer at the same height, or do I need to do a vent in the horizontal line come from the sink trap just as you have shown in the picture at the beginning of this thread?
Offhand, from the pictures, I would suspect that a fixture fitting would make the drain go in the wrong direction and create a convoluted drain if the sink is going along the back, concrete, wall.
So I went to Home Depot and found these two fittings. It appears to me that I need a double fixture fitting, shown on the left. Is this correct? if I replace the T that I have right now with a double fixture fitting I won't need to change the vent at all?
Last edited by bradleonard; 11-21-2010 at 02:30 PM.