ABS to galvanized DWV

[8seconds]

I need to transition from ABS to existing Galvanized DWV pipe. The Vent portion of the Galvinzed is in perfect shape but the drain side is corroded. While I have the plumbing exposed I am taking out the drain galv and replacing with ABS. Is it OK to use a female slip/ male threaded ABS fitting to tie into the steel Galvanized. They are the same thread and it will screw into the galvinzed.

 

[Jeff H Young]

Most of the time I replace the tee as well with plastic cut the vent up above flood level of sink put a band and replace everything on bottom as far as desired

 

[Sponsor]

 

[wwhitney]

Oregon's version of the UPC is not available at up.codes, but California uses the UPC as well and is unlikely to differ for this question.

UPC 705.10.3 says "Where connecting plastic pipe to other types of plastic or other types of piping material; approved listed adapter or transition fittings and listed for the specific transition intended shall be used."

Chapter 7: Sanitary Drainage, California Plumbing Code 2022 | UpCodes

UpCodes offers a consolidated resource of construction and building code grouped by jurisdiction

up.codes

I don't think a generic threaded connection would match that description. So use a Mission Rubber Bandseal or Fernco Proflex shielded rubber coupling that is specifically listed for the size of galvanized to ABS you have.

Cheers, Wayne

 

[Breplum]

Threaded joints, esp. those connections made by amateurs are the least-best choice.
I'd say you could thread it but the absolute better choice are no-hub transition or even standard no-hub couplings after you cut the steel pipe.
Yet, even for those they must be torqued with tools made for torquing no-hub bands.

 

[8seconds]

I spoke the the abs fitting manufacturer and they stated there specifications. Note, this is not Code. If it is threaded plastic to plastic acceptable, if it is male plastic to female steel and not on a hot water line it is acceptable, if it is male threaded steel to female plastic not acceptable. So it sounds like I can do it although may not pass an inspection per the state code. To me it seems strong on the section I did for the vanity. That side is the only side that will have the plastic male threaded/ Hub in a wet drain area. I have to use a fernco on the shower side as they do not make a 1.5 inch donut for cast iron. I will leave a stub of the galvanized to tie into with the ABS. Here are a few pictures. Any further comments either way are appreciated. I'm still waffling about the MPTxhub on the wet vanity side.



This is the shower side Female steel I need to tie into like the vanity side(main floor).

This is where i will put in a banded fernco (basement, rag in cut pipe). The pipe next to it is a vent only for basement drain.



Vanity drain and tie into main stack. this is the only wet transition with MPT and HUB.(basement)




Tie in to vent for vanity sink. main floor