welding coated pipes

[miyo]

I have a project of a water line made of steel pipes coated inside with cement-alumina.
Looking for information aout the right way to weld them without harming the coating.

 

[BarryEng]

Try the pipe manufacturers.

My guess is that the coating will be damaged due to the HAZ (heat affected zone) & will have to be repaired.

If it is an alumina cement coating, I would be very wary - there have been some dramatic failures of HAC (high alumina cent) in tehr UK & Europe many years ago.

I do not know of the system so I cannot comment further.