Kitchen waste water pipe diameter - Confused about waste pipe sizes

[BobG]

Our sink, washing machine and dishwasher all drain out through a U-bend, then a 90 degree compression joint, which brings it to a horizontal pipe. There is then a 135 degree solvent weld turn to align it to the hole through the wall, outside there is then a 90 degree solvent weld downturn to a four foot length of exit pipe which goes into the drain.

The horizontal length of pipe going through the wall blocks up and takes most of an afternoon to clear with various bits of old hose pipe, coat hangers and whatever else I can find to poke up there.

If I were to add a straight coupler near the top of the four foot pipe outside, I'd be able to easily get in there to clear it.
I measured the pipe and it appears to be 44.5mm diameter which looks suspiciously like 1 and 3/4 inches, but everything I can find in the diy stores is 40 mm.

I decided that I'd try a push to fit straight coupler, but there is no chance that this would fit.

I now notice that some retail outlets show the compression joints as "universal": does this mean that it would fit my 44.5mm pipe ? Or do I have to get rid of all the 44.5mm pipe back to the U-bend ?

BobG

[danensis]

Basin wastes were traditionally inch and a quarter (32mm) and bath wastes inch and a half (38mm). You could also get 2 inch waste (50mm) but that tended to be used more for vent pipes.

I seem to recall that one make (was it Marley?) didn't fit into anyone else's fittings or vice versa. Sod's law dictates you'll have one of the odd ones.

[sqidd1g]

Plumb center is the place to go --- had to get some myself recently for a job, and that is where I found it.

[ABILITY]

I think the solvent welded pipe is measured ID whilst socketed pipe is OD, thus you can,t push fit onto solvent pipe, unless as you say there is a converstion size.

[BobG]

Thanks guys, it really is quite odd.

I had a look around the house, and found that the small sink in the downstairs loo, uses a waste pipe of OD(outer diameter)=37mm. In the garage I found a bit of loose pipe that was OD=40.5mm, so along with the kitchen pipe I'm trying to fix at 44.5mm, I have three different sizes of white plastic waste pipe only one of which could conceivably be the 32mm or 40mm types advertised everywhere.

My plan now is to take the 90 degree compression piece between the U bend and the solvent weld pipe to Plumb Center and ask them to provide me with pieces that fit to what I have. This way if they can't provide a solution, I can put everything back as is. One good thing is that I'd be surprised if all the bits I need came to much more than a tenner.

If I'm going to replace the solvent weld then I was hoping that I could get a proper rodding eye, but I haven't seen one of these online, so hopefully Plumb Center will have one.

BobG

[BobG]

As suggested by sqidd1g, I went to Plumb Center and picked up a tub of solvent weld, 3m of pipe, 135 degree solvent weld joint, solvent weld T-piece and rodding eye. £18. Son and I fitted it all today, and so far it seems to work and not leak. The pipe was 43mm OD and 38mm ID. (Yet another size

The 90 degree compression joint seem tolerant of slight deviations in pipe diameter. (Thankfully).

Looking forward to the smugness next time it blocks.

BobG