Steel Pipe Size and Fittings

[sail&fish]

My hot (gravity) and cold (mains) come into the bathroom via galvanised steel (iron?) pipes.

My first question is what size are these steel pipes? The pipe OD is about 21.5mm and the steel Tee body diameter is 26.4mm. I need to know this in case I need to buy some more brass iron couplings (1/2 or 3/4 inch).

Hot:


Cold:


Hot.

The short horizontal length of copper currently connected to the hot is OD 21mm so I assume it is 3/4 inch copper. I would like to replace this with new 22mm; can I use the same fitting with a 22mm olive?. The vertical is probably half inch and the same applies replacing it with 15mm?

Cold. Both pipes coming out from this are 15mm/half inch although I would like to replace one with 22mm assuming the steel has a greater capacity than 15mm as I will tee 3 taps off it.

If I need new couplings I assume I can use screwfix: Male Coupler 15mm x 1/2" (Code 69358); Male Coupler 15mm x 3/4" (Code 82086); Male Coupler 22mm x 3/4" (Code 63073) using PTFE around the threads.

or would I be better off undoing the steel tee and putting on a female coupling.

thanks

 

[aligorgon]

copper pipes measure the OD

steel you measure the ID the both look 1/2" to me

 

[Ermintrude]

Locktight 55 for the threads on iron with a generous smudge of jet blue (plumb center)!

 

[WHPES]

Best use DZR fittings rather than regular brass seeing as they are in contact with steel. You will probably need to use some heat on the fitting to free off the old brassware.

 

[GasmanxxxR1]

All looks like 1/2 inch to me too

 

[sail&fish]

Thanks, is there any benefit in stepping from the 1/2 inch steel to 22mm copper or do I save the pennies and run through to the bath in 15mm.The local Plumbase, screwfix and wickes do the couplings. How will I know if they are DZR and not brass.

 

[IDCHAPPY]

Aye, that's 1/2"

 

[lame plumber]

if your doing a refurb, just rip it out and replace with copper, its probably about to terminally block in the near future anyhow

 

[acecharly]

There are no copper to irons on the bottom of the iron tee so you couldn't do it all in copper. Id lesve the tee in and just fit new copper to male irons to top and center and then do new copper. That tee will last forever.