Connecting Floplast to "normal" 40mm pipes??

[Scarletpimpofnel]

Hi. I have a "normal" 40mm white plastic waste pipe that has compression joints to connect stuff to it. Can I connect FloPlast fittings to this existing 40mm pipe by using Floplast cement/glue? Or will the existing 40mm pipework melt (i.e. not suitable)?

Many thanks.

[CoolHands]

deleted my answer

Even though I ve never come across a problem before and can t see logically how push fit and solvent pipe can be different as what if you need solvent at one end? Also how you know what pipe another installer has used when you want to make alterations? I reckon it s bks but anyway

Edit again from here https://plasticsuppliesdirect.co.uk/solvent-weld-v...

Both systems may be called 32mm, 40mm and 50mm however they are slightly different to this in their exact measurements:
32mm solvent weld pipe has an external diameter of 36mm
32mm push fit pipe has an external diameter of 34mm
40mm solvent weld pipe has an external diameter of 43mm
40mm push fit pipe has an external diameter of 41mm
50mm solvent weld pipe has an external diameter of 55mm
50mm push fit pipe has an external diameter of 54mm

Edited by CoolHands on Saturday 12th July 17:01

[OutInTheShed]

40mm pipe can be solvent weld or pushfit.
Or occasionally some other thing entirely.
The pushfit stuff doesn't weld reliably with the pvc solvent and the two are different variations on not exactly 40mm.

Compression fittings are good for connecting various flavours of 40mm together.

I think Floplast make both solvent weld and pushfit?

[Scarletpimpofnel]

CoolHands said:

deleted my answer

Even though I ve never come across a problem before and can t see logically how push fit and solvent pipe can be different as what if you need solvent at one end? Also how you know what pipe another installer has used when you want to make alterations? I reckon it s bks but anyway

Edit again from here https://plasticsuppliesdirect.co.uk/solvent-weld-v...

Both systems may be called 32mm, 40mm and 50mm however they are slightly different to this in their exact measurements:
32mm solvent weld pipe has an external diameter of 36mm
32mm push fit pipe has an external diameter of 34mm
40mm solvent weld pipe has an external diameter of 43mm
40mm push fit pipe has an external diameter of 41mm
50mm solvent weld pipe has an external diameter of 55mm
50mm push fit pipe has an external diameter of 54mm

Edited by CoolHands on Saturday 12th July 17:01

Thanks. This does explain why some of my 40mm push fit fittings won’t fit on my 49mm pipes!! Some of my 40mm pipes are slightly too big.

Anyway I understand what I need to do now thanks. Up till now I thought 40mm was a standard size.. it seems it’s not.

[Scarletpimpofnel]

OutInTheShed said:

40mm pipe can be solvent weld or pushfit.
Or occasionally some other thing entirely.
The pushfit stuff doesn't weld reliably with the pvc solvent and the two are different variations on not exactly 40mm.

Compression fittings are good for connecting various flavours of 40mm together.

I think Floplast make both solvent weld and pushfit?

I’ve ordered all the bits I think I need and will assemble dry. Some need cementing and done are compression and some are push fit!

Basically the 21.5mm boiler condensate pipe goes into a 40mm welded washing machine standpipe. I need to move the standpipe but it ultimately ends up “normal” 40mm polypropylene pipe (not cemented).

[CoolHands]

Scarletpimpofnel said:

Up till now I thought 40mm was a standard size.. it seems it s not.

Amazing isn’t it. You’d think someone would decide a ‘standard’ would be a good idea, but that’s obviously too sensible.

[98elise]

Scarletpimpofnel said:

Anyway I understand what I need to do now thanks. Up till now I thought 40mm was a standard size.. it seems it s not.

So did I, and I've been doing DIY for decades!

[JoshSm]

Usually you can find an adapter that will solvent weld at one end and be a pushfit at the other. Not quite the same size as the pipes are different each side.

There's also some which are very similar but are a slightly different size which act as expansion connectors - also handy if you want to put a joint in a run of solvent weld that you can pull apart later or just twist slightly. They're designed to weld to a solvent weld pipe and also pushfit to it, but aren't the same as one for actual pushfit pipe.

Edited by JoshSm on Saturday 12th July 18:14

[_Jonesy_]

Solvent weld is imperial - 1 /12 inch which comes out at 43mm
Pushfit is actually 41mm

You need a compression coupler to join them - use a McAlpine multi fit or similar

Edited by _Jonesy_ on Saturday 12th July 18:46

[ashenfie]

Not sure if anyone has pointed out that the solvent won’t work on push fit pipes. Generally push fit are considered bad news by plumbers as the can pop off when someone uses a plunger or messes with the pipe work.

[wong]

CoolHands said:

deleted my answer

Even though I ve never come across a problem before and can t see logically how push fit and solvent pipe can be different as what if you need solvent at one end? Also how you know what pipe another installer has used when you want to make alterations? I reckon it s bks but anyway

Edit again from here https://plasticsuppliesdirect.co.uk/solvent-weld-v...

Both systems may be called 32mm, 40mm and 50mm however they are slightly different to this in their exact measurements:
32mm solvent weld pipe has an external diameter of 36mm
32mm push fit pipe has an external diameter of 34mm
40mm solvent weld pipe has an external diameter of 43mm
40mm push fit pipe has an external diameter of 41mm
50mm solvent weld pipe has an external diameter of 55mm
50mm push fit pipe has an external diameter of 54mm

Edited by CoolHands on Saturday 12th July 17:01

I think they deliberately made them a slightly different size to not make them compatible.
Pushfit are made from polypropylene and so will not melt with the solvent cement. Solvent weld are ABS or PVC but look and feel similar to the polypropylene pipes.
It's maddening when trying to fix leaks.

[cml24]

_Jonesy_ said:

Solvent weld is imperial - 1 /12 inch which comes out at 43mm
Pushfit is actually 41mm

You need a compression coupler to join them - use a McAlpine multi fit or similar

Edited by _Jonesy_ on Saturday 12th July 18:46

Agree with this. And don't skimp on the manafcture, just get the mcalpine for about 1 pound more and don't have any leaks!

[Scarletpimpofnel]

cml24 said:

Agree with this. And don't skimp on the manafcture, just get the mcalpine for about 1 pound more and don't have any leaks!

I notice McAlpine stuff is double the price... you get what you pay for I guess ty.

[ashenfie]

Scarletpimpofnel said:

cml24 said:

Agree with this. And don't skimp on the manafcture, just get the mcalpine for about 1 pound more and don't have any leaks!

I notice McAlpine stuff is double the price... you get what you pay for I guess ty.

McAlpine is very quality and I normally use them for waste joints etc

[Ardennes92]

CoolHands said:

Scarletpimpofnel said:

Up till now I thought 40mm was a standard size.. it seems it s not.

Amazing isn t it. You d think someone would decide a standard would be a good idea, but that s obviously too sensible.

I think someone did, it was called imperial🤔,

[Scarletpimpofnel]

OutInTheShed said:

40mm pipe can be solvent weld or pushfit.
Or occasionally some other thing entirely.
The pushfit stuff doesn't weld reliably with the pvc solvent and the two are different variations on not exactly 40mm.

Compression fittings are good for connecting various flavours of 40mm together.

I think Floplast make both solvent weld and pushfit?

I’ve ordered all the bits I think I need and will assemble dry. Some need cementing and done are compression and some are push fit!

Basically the 21.5mm boiler condensate pipe goes into a 40mm welded washing machine standpipe. I need to move the standpipe but it ultimately ends up “normal” 40mm polypropylene pipe (not cemented).