38mm (1.5 inch) outside diameter pipe is a pipe size that you come
across when dealing with flushpipes. Is it used by anything else ??
And cistern outlets usually have a compression fitting for this size
of pipe, and the flushcone to connect to non-direct-coupled toilet
pans fits this size pipe.
Most plastic plumbing pipes are 1.5mm wall, so that 32mm pipe is 35mm
od, 40mm pipe is 43mm od, and 38mm od is too small for 40mm
compression fittings and too large for 32mm compression fittings
So if you need to make connections in 38mm pipe (e.g. where the other
option is a flexible cistern to pan connector), you are stuck. Almost.
I needed a dogleg since the cistern must be offset, and I've heard bad
reports about the flexi pipe (water pressure moves it and connections
So I went to get a highlevel flushpipe to use the dogleg from
plumbcenter, which turned out to be crap, with the dogleg being wonky.
However, it also turned out to have a 32mm id / 35mm od pipe that
pushed down with interference fit into the 38mm od pipe so the overall
length could be adjusted. Interesting. That would be fine for a flush
pipe, since its not under much pressure for any length of time.
It also came with an adapter to convert the cistern outlet compression
to a 32mm od flange.
So I will do this: connect 32mm (35mm od) standard pipe into the L
bend (38mm od, 35mm id) flush pipe just by pushing it in with a decent
overlap, connect 32mm pipe at the top using the special flange, and
use an adjustable 32mm connector and the variable length overlap to
get things lined out without pulling on the flush cone or weedy and
rather bending plastic concealed cistern I got.
But anyone know of fittings available to fit 38mm o/d pipes ?
Any make of 40mm compression that will seal up to 38mm pipe ?
I am amazed the bodgery required to do such a simple job.