Cast Iron to PVC?

Users who are viewing this thread

Jadnashua

Retired Defense Industry Engineer xxx
Messages
32,770
Reaction score
1,190
Points
113
Location
New England
Our state uses 2015 IPC. I live in a row of townhouses. We have a main sewer line that runs along the foundation wall sitting in open air and part of that is in garages, so while enclosed when the door is shut, it can get cold in there. Currently, that line is CI, but many people put in condensing furnaces, and did not install neutralizers which has the pipes eroding. The proposal is to replace it with PVC, but I don’t think this will work well. The run is essentially straight 200’ and goes through poured concrete walls between units and each unit has two wyes that connect to it, often along the foundation walls, constraining any expansion. I have estimated a max temperature variance of 70-degrees between the pipe and contents. Which calculates to slightly over 5” of length change. While there are sliding bellows type fittings that can accommodate that change, I’m not familiar with their long-term reliability or performance and if there were a fire or the PVC got damaged, it could make the other units upstream uninhabitable.

My preference is to replace it with hub-less ci and install neutralizers where required.

Are there any code issues that would force this one way or the other?
 

Fitter30

Well-Known Member
Messages
4,292
Reaction score
778
Points
113
Location
Peace valley missouri
Have had very few problems with expansion fittings for chilled and hot water. No experience with drains. The problems condensate contains different types of acids that are corrosive to many materials and contain concentrations of nitric, nitrous, sulfuric, and sulfurous and hydrochloric acids. So gaskets and materials have to made for the acid.
 

Jeff H Young

In the Trades
Messages
8,766
Reaction score
2,168
Points
113
Location
92346
Going through walls from one townhome to another could have fire rating issues with plastic. I've transitioned to metal pipe for wall penetrations but never tried a sleeve assuming the sleeve would still have trouble with compliance. But don't know if from garage to garage would have fire rating requirement but would expect likely
 
Top
Hey, wait a minute.

This is awkward, but...

It looks like you're using an ad blocker. We get it, but (1) terrylove.com can't live without ads, and (2) ad blockers can cause issues with videos and comments. If you'd like to support the site, please allow ads.

If any particular ad is your REASON for blocking ads, please let us know. We might be able to do something about it. Thanks.
I've Disabled AdBlock    No Thanks