Is this the proper way to connecting ABS and PVC in stack?

[pistiloyd]

The Saniflo compact uses just a 1" drain. I am getting estimates from plumbers to complete the drain, but I am getting different opinions on how to do this. It goes back to my original question of if this should be connected directly to the stack or to the horizontal line. Saniflo says it can be done either way. Preferred method would be to not have to cutout drywall to gain access to the stack. However, it seems like my little knowledge of plumbing says that the 2" horizontal branch line would be undersized and shouldn't have this 1" discharge tapped into it.

The horizontal branch has 1 shower 2 units), 1 bathroom sink (1 units) and 1 kitchen sink/dishwasher 2 units) drain hooked up. Looking at the a DFU chart, this is a total of 5? Adding in a Saniflo (1.28-1GPF) would mean the 2" line isn't adequate because that would be an additional 3 DFU? I want to make sure I feel confident with whomever we hire and they are using best practices and not just opinions. Thanks!

 

[Jeff Handy]

IIRC, Saniflo only has a cheapo rubber check valve that prevents back flow of discharge.

I would feel better dumping the line right into a stack than competing with those other fixtures that might try to run back into the Saniflo.

 

[TomFOhio]

Does your manual say the 1" saniflow line should be tyed into a 3 or 4" horizontal line?

 

[pistiloyd]

When I called they told me that it can tie into any waste line as long as it empties into the soil stack. It is common for others to tie it into their 2" waste line, but I know that doesn't mean it is right. Saniflo just wants to make sure you aren't dumping into a floor drain basically.