jmetrail
New Member
I'm doing an ABS to cast transition.
4" cast connected to a 4" to 3" ABS bushing.
The bushing has a spigot end that should be identical diameter to 4" ABS pipe, so I figured a regular hubless 4" shielded coupling would work. (I used this one: https://www.americanvalve.com/product/rnhhd/)
Problem is, the diameter of the cast seems to be slightly off - it's a slightly larger diameter than the ABS, to when tightened, the coupling shield buckles (since the ABS-side clamp has to be tightened more than the cast-side clamp).
I poured some water down and it doesn't seem to leak - but it doesn't look to pretty (pic below).
Is there a better coupling for this?
Also wondering if I can wrap the ABS with a bit of sealing tape to increase the diameter to better match the cast?
4" cast connected to a 4" to 3" ABS bushing.
The bushing has a spigot end that should be identical diameter to 4" ABS pipe, so I figured a regular hubless 4" shielded coupling would work. (I used this one: https://www.americanvalve.com/product/rnhhd/)
Problem is, the diameter of the cast seems to be slightly off - it's a slightly larger diameter than the ABS, to when tightened, the coupling shield buckles (since the ABS-side clamp has to be tightened more than the cast-side clamp).
I poured some water down and it doesn't seem to leak - but it doesn't look to pretty (pic below).
Is there a better coupling for this?
Also wondering if I can wrap the ABS with a bit of sealing tape to increase the diameter to better match the cast?
