New piping - imperial or metric?

spr1nt3r

Replacing old pex pipe for radiator run with copper one. Would I be better of going mettic 22mm vs imperial 3/4 inch? What is better futureproofing wise?

Don't want to start a war or sound silly but why is imperial still used when even UK fonverted their piping to metric?
Thanks all. Please keep it civil.

embracingLife

In Ireland we don't use Imperial or Metric pipe sizes- instead the size is called "Irish". Its slightly smaller than UK Imperial sizes, about .3mm smaller.
Eg half inch is 14.7mm not 15mm (its stamped on the brass fittings).

That's it. No if, ands or buts about it.

Stick with this sizes in local hardware/plumbers & builders providers which is the "Irish" size fittings & pipes, copper, brass, pex etc.

spr1nt3r

embracingLife wrote: »

In Ireland we don't use Imperial or Metric pipe sizes- instead the size is called "Irish". Its slightly smaller than UK Imperial sizes, about .3mm smaller.
Eg half inch is 14.7mm not 15mm (its stamped on the brass fittings).

That's it. No if, ands or buts about it.

Stick with this sizes in local hardware/plumbers & builders providers which is the "Irish" size fittings & pipes, copper, brass, pex etc.

Thanks. I was only asking as I got 1/2 and 3/4 inch fittings from Heat Merchants swearing these are Irish standard but Screwfix sold me 15mm and 22mm pipes. You're saying 14.7mm is in use which I saw on adapter left by plumbers. Now I am even more confused...

embracingLife

Heatmerchants gave u the Irish sized fittings- its standard size in Ireland.

Screwfix is a Uk company with a few shops here and an Irish version of their website and will probably sell u the metric sizes unless u specifically pick the Irish sized fittings. I dont use Screwfix so Idk what they sell on their site.
Clarify on Screwfix site what exactly sized fittings you buying before u buy from them.

embracingLife

14.7mm is stamped sometimes on some half inch fittings-this is the metric size of "Irish half inch". But Dont ask in shop for 14.7mm just ask for "half inch" which is the Irish half inch.

I only mentioned this 14.7mm purely to explain to you the differance between "Irish" pipe sizes and Uk metric sizes.
Irish pipe sizes are Always sized in Imperial- which are the Irish Imperial sizes which are slightly Smaller (approx .3mm smaller) than Uk Imperial- so when you go into Irish suppliers they will give you the "Irish" sized Imperial sizes.

Filmer Paradise

Just to confuse things a bit more.

Metric pipe is measured on the outside diameter.

Imperial pipe is measured on the inside diameter.

So, the Irish pipe is 12.7mm bore, add on the thickness of the pipe & it comes to 14.7mm.

Not quite the metric 15mm, which is measured on the outside.

corkgsxr

There is no Irish size. We use imperial size that it. No more complication.

Other places use metric. Which is a tad bigger.


I would use Imperial. That's fairly standard here