Clad Pipes 2

[Angsi2]

The project has substantial CRA piping material application (because of wet CO2 corrosion). We are looking at ways to reduce cost and one of the option was cladded piping and components.

A couple of main concerns with cladded pipes:

1. When there are instrument openings on cladded pipes (2" openings example for pressure gauges and transmitters etc.), the thru holes in the pipe wall thicknesses will be exposed to the corrosive fluid (take for example A106 B + 3mm 316L clad). Assuming the pipe spools are fabricated at site and with multiple instrument openings, are clad pipes a good recommendation for application? Otherwise how will the exposed CS metal at holes be protected? Will we be better off with solid CRA?

Is there anyone here with good clad pipe/fitting experience who can provide some suggestions and share other difficulties with clad piping?

 

[SJones]

Do as much spooling in the shop as you can and get field welding down to a minimum. If you are using weld overlay as the cladding method, and the spooling contractor is also the weld overlay contractor, they can sort out the instrument attachments.



Steve Jones
Materials & Corrosion Engineer

http://www.linkedin.com/pub/8/83b/b04

 

[pennpiper]

Don't punch a hole in the clad pipe for conventional instrument taps.
Consider using 316L Bleed Rings for all instrument taps, vents, drains etc.

 

[KOCLAD]

We have manufactured many clad piping systems from clad plate and weld ovearlay. The 2" nozzle opening can be designed in two ways.

Option 1 is to install a weld overlay 2" RFLWN. The wetted surface or the end of the nozzle should be overlayed. The weld should be a solid alloy weld. Specify 309LMO for the welding consumbale for the overlay. The nozzle to base material weld can be solid 309LMo or preferably Alloy 625.

Option 2 is to install a solid 316L (or alloy) special coupling or forging and weld using 309LMo or preferably Alloy 625.

http://www.canadoilgroup.com