What is the internal diameter of a steel pipe with external diameter of 43mm or 1.7"?

[LordWest]

What is the internal diameter of a steel pipe with external diameter of 43mm or 1.7"? Below is a photo if that helps. This was installed before 1975 and is being used for communal hot water.

 

[Rtplumb]

Looks like 1” to me, going by the photo with the lead pipe next to it. It’s difficult to gauge a pipe from a photo. The max it could be is 11/4” but I’m going for 1”.

 

[ShaunCorbs]

Looks like 1” to me, going by the photo with the lead pipe next to it. It’s difficult to gauge a pipe from a photo. The max it could be is 11/4” but I’m going for 1”.

11/4” mate as steel od works out next size up etc

Op I’d would be around 25-28mm why do you ask ?

If you look on the lock ring / fittings you might see a size stamped in

 

[LordWest]

Looks like 1” to me, going by the photo with the lead pipe next to it. It’s difficult to gauge a pipe from a photo. The max it could be is 11/4” but I’m going for 1”.

The pipe next to it is also a steel pipe. The external diameter of the white pipe is 43mm, as I measured with a caliper. This pipe supplies several flats hot water.

 

[exedon2]

As above 1 1/4 wall thickness depends on what quage normally medium or heavy,
It's probably a fair age that's a long thread jointing section by the late 60s unions were being used.

 

[LordWest]

11/4” mate as steel od works out next size up etc

Op I’d would be around 25-28mm why do you ask ?

If you look on the lock ring / fittings you might see a size stamped in

I am asking because several of the steel pipes that provide communal hot water to several flat are in poor state (i.e. rusty on the inside) and we need to plan in replacing them with either multilayer or copper pipes. If I know the internal diameter of this 43mm external diameter pipe, I can better plan for alternative solutions.

 

[ShaunCorbs]

I am asking because several of the steel pipes that provide communal hot water to several flat are in poor state (i.e. rusty on the inside) and we need to plan in replacing them with either multilayer or copper pipes. If I know the internal diameter of this 43mm external diameter pipe, I can better plan for alternative solutions.

They will be / should be galv so doubt it’s rust probably water scale / contamination

Do you own the flat / all tenants own / rent privately

 

[LordWest]

They will be / should be galv so doubt it’s rust probably water scale / contamination

Do you own the flat / all tenants own / rent privately

"Maybe" that section is galvanized. However, here is a photo of an earlier section of the same supply that is completely rusty inside. This was a connection with a larger diameter and thus not much of help for my query.