40mm piping - welded parts / coupler / compression question

[joeblow47]

Newbie - elemental parts-ordering question here:, relating to the size i need to refer to / compatibility when ordering replacement pipe parts.

For 40mm piping (under sink / washing machine arrangement) - see photo

1. For 40mm piping, when ordering welding couplers, welding bends and welding equal tees is the generic size part for all 3 also known as 40mm ? So 40mm bend fits 40mm pipe ?
ALSO
2. Where welded 40mm pipe work attaches to compression-designed parts such as a u-bend, is the generic sizing to order for the compression part also known as 40mm ?

Many thanks
jb

 

[joeblow47]

wow - 60 views and not a sausage ....

 

[ShaunCorbs]

Yes keep to the same brand tho as some could vary

Compression fittings will take any 40mm pipe

4 another point for a dishwasher

 

[gpbeck]

It might be worth dismantling the u bend at bottom of washing machine waste pipe and clear it out. The small pipe at the back is a fitting for a dishwasher or washing machine hopefully it’s capped off inside. Whoever put this together didn’t plan at all so it is very tortuous and prone to block. Technically you should be able to clear the whole system with rodding with something. If I changed that, I’d plan it better and just use 40mm push fit properly clipped with a compression fitting on the final kitchen outlet. Easier to take down when blocked.

 

[joeblow47]

Yes it's an old social housing build;
I'm going to add an Equal-T with access cap to the left side arrangement (to mirror the right side end cap) because the blockage has occurred on the horizontal piping. That said they've lasted 20-25 years before becoming blocked.
1. Should i introduce a slight gradient to these horizontal pipes ?
2. Where the pipe is welded to the main pipe at the rear / going into a grey reducer - what's the best way to dismantle that weld without the need to damage/replace the main pipe at the rear ? Is there a stock method to unweld the solvent ?
3. Someone else has suggested running the washing machine pipe-work directly into the sink pipe work - i'm unclear where best to join them and if it still needs it's own u/p-bend ?

cheers
sp

 

[gpbeck]

Something like this from Mcalpine directly beneath basin and washing machine hose on the fitting. Chuck loads of pipe out and run the outlet of this down with 40mm pushfit and an elbow or 2 down to your (50mm?) outlet. Shorten 50mm pipe then fit solvent weld reducer 40mm to 50mm and use a compression fitting push fit to the new 40mm fitting. Keep everything high, Pop in a shelf and you’ll gain useful storage space too!

 

[joeblow47]

Something like this from Mcalpine directly beneath basin and washing machine hose on the fitting. ...........Keep everything high, Pop in a shelf and you’ll gain useful storage space too!

Thanks for this solution:-
I can see how you mean i can just remove the entire left had pipe work. For the larger outlet pipe at the rear you seem to be suggesting cutting and replacing it with a single reducer connection arrangement.

1. Will a washing machine attached to a spigot so close to the kitchen sing plug-hole send waste water up into the sink before it goes through the u-bend ? Is there a workaround/protocol to stop that from happening ?
2. For washing machine hose attachment to a spigot -should i secure that hose with some kind of special clasp to stop it popping off ? if so what's the part called ?
3. Should i keep an access plug in the main 50mm outlet pipe as it's horizontally laid ? (it currently runs to an access cap just beyond the cupboard wall on left.)

cheers
sp

 

[gpbeck]

Well why do you think they sell them with a spigot?? Having greater flows through one pipe helps to keep them clear. A jubilee clip that covers 29mm will do it so that’s a quid. You could cut through the 50mm pipe to the left of where your 40mm will go ( shorten it though) and cap with a solvent weld plug fitting if you wish. You have to cap it with something.

I’d cut through the 50mm to the right of the photo if possible (obviously I can’t see this) to leave more storage space.
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And perhaps you already have the part I suggested acting as a u bend on the left. Maybe a non plumber was given it and ‘made it fit’

 

[joeblow47]

hi - thanks for continued advice

1. i think you're right - well spotted - the u-bend on the left is the same as the part you advised i purchase.
2. i've attached a new pic of the entire rear 50mm outlet pipe. (Ignore the foam ). Would you recommend cutting the rear outlet pipe adjacent with the 1st or 2nd copper pipe from left ? I would then imagine to attach a new 50mm equal-T, with an access plug at the left and the sink piping entering via a solvent weld 50-40mm reducer (can i use any reducer design or do you suggest specific type ?) at the front as it currently is ?
3. If i did the arrangement at 2 above, should i replicate the current front facing 40mm equal-T with access plug too so i have 2 access plug points ?

If this is all about right - let me know if there's anything else i should take into account - and only to thank you for your time and advice !

cheers again
sp

 

[gpbeck]

No one access point inline with the 50mm pipe is fine. What you propose is good. 50mm pipe is only necessary for a run over 3 metres. If it’s that long make sure it has a fall left to right only about 25mm for each metre. If the pipe has no fall it may permanently hold fluid. You’ll find out when you cut it...

 

[joeblow47]

No one access point inline with the 50mm pipe is fine.

One last thing! - for the 50mm pipe access plug- does a conventional access plug weld directly to the equal-tee or require a section of straight 50mm pipe ?

sp

 

[gpbeck]

One last thing! - for the 50mm pipe access plug- does a conventional access plug weld directly to the equal-tee or require a section of straight 50mm pipe ?

sp

I’d use a swept tee like you already have for better flow. You’ll need a bit of 40mm If tee you get has female ends.