Thread sizing in 1958

[mfarrow]

Hi

We have some old central heating piping in our house which dates from 1958 and is threaded steel from which I'd like to extend/replace a section.

Would this be BSP or some other random size? Would standard MI/FI adaptors be OK with these?

I don't want to start pulling things apart you see and then find I'm stumped for the right parts.

Many thanks

 

[JohnD]

pretty sure to be BSP

however the pipe ends will probably have been threaded on-site using a huge iron adjustable die (my old dad used to do that) and although the thread is right, they may be cut a bit deeper or a bit shallower than usual, depending on how sharp the dies were and how tight they were set, so you may have to wind the fitting up and down the pipe a few times to get it running freely. The old jointing compound will seal the thread if it is cut a bit loose.

 

[SandyLyon]

Also remember that iron pipe was sized internally. So what might look like 1" will probally be 3/4" etc. (when buying MI / FI connectors)

 

[Charnwood]

(my old dad used to do that)

Been there, done that.
When I first left school, where I worked we fabricated bits and pieces for the bone idle fitters who could not be ar.....
Anyway, we had a lathe for the bog standard work, but there were some intricate bits that had to be done by hand. Anything up to 2" BSP.

 

[Boilerman2]

It wil be and still is BSP

And we are still threading pipes to-day - albeit with a Rigid Power die!!
forget Hand-dies!!

 

[Charnwood]

Power die?!?! Wimps!

 

[mfarrow]

Thanks all.

It looks like I'm onto a winner then.

Found on my travels, the following chart may be useful for someone in the future:

http://www.ring-plug-thread-gages.com/PDChart/BSPT-JIS-thread-data.html

 

[MANDATE]

If you're replacing a section of pipe, how do you propose to cut the required threads.

 

[SandyLyon]

Just hope there is a union handy, otherwise the OP may be in a spot of bother

 

[MANDATE]

Don't see how a 'union' will help.
But Machine Mart do sell pipe threading kit.

 

[SandyLyon]

Breaking the union will allow him to unscrew the pipe work in both directions back to either a socket or pipe thread so that a MI or FI fitting can be used

 

[MANDATE]

Don't disagree with that, but any replacement pipe will need threading if it's steel, perhaps the intention is to change to copper.

 

[mfarrow]

Just to put everyone's minds at rest, I'll be installing copper up to the next union. I might buy a die to clean the threads up though, else a cheap fitting and cut down the thread with a hacksaw blade.

 

[Biggles..]

Don't disagree with that, but any replacement pipe will need threading if it's steel, perhaps the intention is to change to copper.

Erm could use a VJ or primofit coupling. No threading needed.

 

[Dan Robinson]

Hateful things, but they have their uses.


Read the destructions very carefully.