21mm copper pipe ??

[oska37]

I'm currently updating the bathroom and have bought some new mixer taps to fit to the bath. I've measured the hot water pipe and its Diameter is 21mm .. the pipes are over 30 year old so they must be imperial.
Can someone tell me if this is the old 3/4 " size pipe..??
By my basic calculations ,3/4" works out to be just over 19mm

Perhaps the old imperials were measured from the internal bore as against the metric being against the outer diameter

Apologies if this is a basic question but I've tried googling it and cant find out

Thanks

 

[gassafeengineer]

pop into suppliers and ask for an old to new straight

metric to imperial copper straight basically

 

[Burnerman]

Yep, thats the old 3/4" pipe....convert to 22 as soon as you can by using a 3/4" olive into a 22mm compression fitting and tighten up well.
At one time you could buy converter olives with 2 grooves (often coloured green) but I haven't seen them for a while.
John

 

[oska37]

Thanks for the quick response lads. What I really need is a flexi with a 22mm tap connector and a 3/4" compression fitting on the other end,I'll check out the Screwfix website to see if they are available...if not, I suppose the 22mm Compression with the 3/4 olive will do the trick.

Noticed you are both from this end of the country,I've always said us northerners are the most helpful

 

[powell30]

Or use a 22mm jg pushfit.....bit tight but they work fine too

 

[ManxPlumber]

Standard compression flexy with 3/4" olive works fine

 

[petit_pablo]

Or use a 22mm jg pushfit.....bit tight but they work fine too

Wouldnt trust 22mm pushfit on 3/4"

 

[AkuraEngineer]

Wouldnt trust 22mm pushfit on 3/4"

I 2nd that

 

[Mart10]

Wickes:-

Solder Ring Tube Adaptor
Product Code: 420156
Size: 22mm x 0.75in

£3.80

 

[nishnish]

Some pipe info here:

http://www.gizmology.net/pipe.htm

 

[TicklyT]

....By my basic calculations ,3/4" works out to be just over 19mm....

That sounds about right - old Imperial sizes measured the bore of the pipe, where metric pipes are sized by the outside diameter. A 3/4" (19.05mm) pipe with a 19 SWG (1.016mm) wall thickness would have an outside diameter of 21.082mm

 

[Nige F]

a 22mm jg pushfit.....bit tight but they work fine too

Tight

I thought 3/4 was smaller O.D than 22

 

[Onetap]

That sounds about right - old Imperial sizes measured the bore of the pipe, where metric pipes are sized by the outside diameter. A 3/4" (19.05mm) pipe with a 19 SWG (1.016mm) wall thickness would have an outside diameter of 21.082mm

It is imperial PIPE; the bore is the nominal size.

It is metric TUBE; the outside diameter is the nominal size.

 

[Nige F]

What about conduit Have a look at Ordnance Survey Grid TQ4110

 

[powell30]

3/4 is a tight fit onto a pushfit fitting. If anything it is more secure than onto a 22mm pipe.....and yes it is not recommended, and yes sometimes the fit is too tight and you pinch/split the rubber seal.....it was just another suggestion. In an ideal world end feed 3/4 to 22mm or 3/4 compresssion olice.....