Cutting a BSP thread in 1/2" iron pipe using

[SillyBilly]

I have had a standpipe tap from when the house was built.  It came off the plastic mains at a T joint and leads to a gun-metal stopcock and the tap.  Though the condition of the rest of the pipe seems good the pipe broke off just below the stopcock  and took most of the pipe thread with it.  Turning the mains off at the road I have  effected a temporary repair using a hose and two good stainless steel pipe clips so  we have now a water supply in the house on 1/2 pressure.  I gave up cutting out the concrete to replace the standpipe but it was solid concrete and probably deep and the main electricity supply is nearby!  So I have to cut a thread in situ and wont have a vice to stop the pipe stub turning!

I  have bought a Silverline pipe ratchet threading kit (868556) from Toolstation which includes a 1/2" die and have cleaned up the pipe.  My plan is to use a long handled stilson to stop the pipe stub rotating.  I have viewed someone on U-tube and wonder if my plan is realistic as I cant risk the pipe turning.

[Conor]

Just use one of these.

 

https://www.bes.co.uk/25-mm-x-21-mm-27-mm-straight-universal-transition-fittings-polyfast-13545/

 

That's how I connected to my lead pipe. Just note you'll need a good length of pipe available in order to get it on. Going by the photo, Im not sure you have enough. May need to chip away.

[Temp]

If you've cut threads before you may already know how to do it but..

 

Clean up the outside of the pipe to remove any old paint or cement etc first.

Adjust the die. Most die have a gap for a tapered screw so they can be adjusted looser/tighter. I would open it up to make the initial cut easier and do it in several passes tightening the die a little each time.

Lubricate the die with oil.

Back off the die regularly. Eg half a turn forward, quarter turn back, repeat.  Perhaps even smaller steps if it gets tight. Looks like you might have to go slow  anyway due to the proximity of the walls.

Clean oil off.

 

Perhaps paint marks on the pipe and floor first so you can clearly see if its turning. 

 

[Temp]

Edit: Actually the way the die is adjusted is probably different at that size.

[JFDIY]

Those dies aren't adjustable, they cut a tapered thread.

 

I've a similar set, did a load of compressed air in my garage years back, anyway I guy I worked with borrowed it to thread a gas pipe for his plumber and managed it.

 

I'd say access will be a bigger part of the puzzle, the die goes on the way you have photo'd it and the ratchet job beneath that, so having room to swing it might become a fair task.

 

At the end of the day, unless you can get to the joint and undo the broken stub, what other choices have you got, it's already knackered.......

[SillyBilly]

15 hours ago, Conor said:

Just use one of these.

 

https://www.bes.co.uk/25-mm-x-21-mm-27-mm-straight-universal-transition-fittings-polyfast-13545/

Thanks for all the replies.  Is there one for iron to 15mm copper, or even simpler for my set-up iron to iron with no thread on either piece, because I  could first cut a thread on the upper piece to fit my stopcock and riser. A link to one would be good to have preferably Toolstation or somewhere local

[markc]

23 minutes ago, SillyBilly said:

Thanks for all the replies.  Is there one for iron to 15mm copper, or even simpler for my set-up iron to iron with no thread on either piece, because I  could first cut a thread on the upper piece to fit my stopcock and riser. A link to one would be good to have preferably Toolstation or somewhere local

Depending on the outside diameter of the iron pipe, you may be able to use a compression fitting, several options available for plastic to lead etc.

[SillyBilly]

The pipe is 21.5 or 21.7mm OD so I think I will use a Philmac 1144

[SillyBilly]

On 28/06/2021 at 10:00, SillyBilly said:

The pipe is 21.5 or 21.7mm OD so I think I will use a Philmac 1144

I went for the Philmac 1143 at the same price.  This is 21-27 x 15-21.  The nuts are quite big at 70mm and I didnt have  a wrench that size and the stilson wouldn't fit.  Had a brainwave and used a oil filter wrench.  The one I have is from Lidl and is thin and easy in a confined space.  No leaks at the main connector but will have to remove the stopcock to fit insulation and tap.