Custom basin waste fitting - what material to use

[andrew2000]

Hello,

Q - Which is better for a CUSTOM basin waste - PVC or Aluminium?


For 2 disabled colleagues I am considering a custom basin waste fitting (I am both Eng & Ergonomist).

Conventional solutions:
- Extends about 94mm below the basin, which even with a low height basin (115mm) only leaves a couple of inches leg clearance.
- Involves several fittings to knuckle bend & drop from 1-1/2" down to 3/4" hose barb re typical pumped application.

Alternative solution:
- Extends 45mm below the basin.
- Involves no extra fittings, has integral side outlet 3/4" hose barb.

CADing this out is trivial.

I have emailed WRAS (not a legal requirement, but may have some info) about what materials I can use.
- PVC is easy - and trivial to bond a hose barb into
- Delrin is easy - and a bit more involved re choice of adhesive
- Aluminium is easy
- Brass is expensive

For some reason I can not recall seeing aluminium in waste plumbing, only PVC (& ubiquitous ABS PP) and Brass.


Ironic only the USA has come up with a back outlet Inset "vanity" basin, that is from ADA beating someone with a hose... there is a large market globally for a few niche (read UK manufacturer could run off) basins. I remember the quality of Royal Doulton toilets... now there was a well made throne.

 

[AWheating]

id use brass or stainless steel.

alu is probably not used due to reactions to soap and cleaning chemicals, maybe??

 

[andrew2000]

id use brass or stainless steel.
alu is probably not used due to reactions to soap and cleaning chemicals, maybe??

Yes, I think chemicals might be it re aluminium.

Brass is much cheaper to buy & machine than stainless. However I am warming to PVC as it is broadly used and this is not an application subject to high pressure, underground, UV exposure or high temperature (TMV).