Laurindo
Mechanical
- Jan 12, 2009
- 2
We have been suffering with pitting corrosion on two removable piping spools (super duplex stainless steel). Corrosion is located on the welds at the elbows.
- the medium is seawater.
- the spool is located at the outlet of the plate heat exchanger.
- it is a 12" schedule 10 pipe(s).
- low operating pressure (9 bar); Design pressure = 15 bar.
- Operating temperature = 65 deg C. During de-waxing = 90 deg C.
at first we though it was probably a bad weld, so we fabricated a new spool and replaced the removable spool. It took only 2 months operation for corrosion to emerge again.
I am looking at buying replacement piping spools in Titanium Gr7 or Gr12.
the problem with that:
down stream of the pipe in question i have connected a carbon steel valve followed by super duplex pipe.
Note: last time found corrosion on the faces of the valve (wrong gaskets).
Does anyone have experience on what do I need to do to successfully make this work without bringing more problems on board due to dissimilar materials? any proven techniques out there?
- the medium is seawater.
- the spool is located at the outlet of the plate heat exchanger.
- it is a 12" schedule 10 pipe(s).
- low operating pressure (9 bar); Design pressure = 15 bar.
- Operating temperature = 65 deg C. During de-waxing = 90 deg C.
at first we though it was probably a bad weld, so we fabricated a new spool and replaced the removable spool. It took only 2 months operation for corrosion to emerge again.
I am looking at buying replacement piping spools in Titanium Gr7 or Gr12.
the problem with that:
down stream of the pipe in question i have connected a carbon steel valve followed by super duplex pipe.
Note: last time found corrosion on the faces of the valve (wrong gaskets).
Does anyone have experience on what do I need to do to successfully make this work without bringing more problems on board due to dissimilar materials? any proven techniques out there?
