4" grommet but existing pipe is 3"

[Qwertyjjj]

I'm in the process of replacing a sewage basin. The house waste pipe that goes into the old sewage basin is 3" yet I have a 4" grommet and 4" hole in the new basin. How can I seal this up properly?

 

[Standardairconditioner]

If the "house waste pipe" has standard O.D. size as typical abs/pvc dwv pipes, then you can use an adapter.

They even have rupper no-hub couplers that that reduce different sizes.

 

[Sponsor]

 

[Qwertyjjj]

If the "house waste pipe" has standard O.D. size as typical abs/pvc dwv pipes, then you can use an adapter.

They even have rupper no-hub couplers that that reduce different sizes.

So you use the adapter in reverse, like an expander instead of a reducer?

 

[Standardairconditioner]

Ya I have a hard time too, looking for a beer brewery that made bottles for the left hand.

 

[Cacher_Chick]

You always go bigger in the direction of flow. What you want is a 4x3 spigot flush bushing, or you use a stub of 4" pipe into the basin.

 

[Qwertyjjj]

You always go bigger in the direction of flow. What you want is a 4x3 spigot flush bushing, or you use a stub of 4" pipe into the basin.

then why are they called reducers? That would be smaller in the direction of flow.