Djaz: Plastic Lined Steel pipe issues! 3

[DjazAutomation]

Hello,

I would like to know how to install plastic lined steel pipe in a typical process.

Is it true that Lined pipes must be purchased premanufactured by specifying precisely the lenght of each unit, beacause it is impossible to cut the pipe the right lenght on site (Can Affect the plastic internal coating in the cutted section.)

If it's true, it would be really a problem for me since it's quiet difficult in my project to have exact lenghts (no precise Isometric pipe drawings available). I guess in this case we have to have very precise isometric drawings. Is there any other way?

Do you think that, like conventionnal steel pipes, plastic lined steel pipes lenghts can be ajusted on site to match each installation case?

Thank you very much.

Djaz.

 

[micalbrch]

Refrain from unnecessary double posting (see Pipelines, Piping and Fluid Mechanics engineering). If you get no answers within a few days - o.k. But double posting means that engineers who help in forum A don't learn what other engineers in forum B answer to the same question.

 

[Compositepro]

One of my first projects out of college was installing a couple thousand feet of Kynar lined steel pipe in a vinyl chloride plant. It cannot be field fabricated.I had to measure every inch of the run by climbing the pipe racks and seeing where the pipe would fit and not block access to valves, etc. Take your measurements diligently (record it on isometric graph paper), and the pipe will go in faster than standard pipe fabricated in the field. Buy a couple of spacers and 6" spools just in case.

Maybe engineers don't climb pipe racks anymore.

 

[ash9144]

No cannot be field fit. As composite says you have to get the exact measurements, whether you or a pipe designer does it . You will have to make sure you have a good clear run to avoid obstructions.

Also you better have a crew that is familiar with lined pipe. Make sure all the pieces are marked and installed in the proper order. If a piece is just a "little" short do not allow them to make it up by forcing the pipe together. This will tear your liner.

 

[moltenmetal]

Yes, you can field-fabricate SOME types of "plastic"-lined piping, at some size ranges. 1"-3" Teflon-lined Crane Resistoflex Thermalok pipe is an example.

Beyond 3"? Forget about it.