Protection of Steel Pipe From Under Insulation Corrosion

Background: BP operates large oil operations on the North Slope of Alaska. They currently use "foam in place" inside a metal shell to insulate and protect the carbon steel piping used to move product. The foam used for insulation tends to absorb moisture causing rampant corrosion of the piping. This corrosion can lead to costly leaks and possible shutdowns. BP would like to treat the foam to prevent future corrosion.

Purpose: Evaluate the corrosion protection provided by VpCI-658M to the carbon steel pipes in the clamshells provided by BP Oil.

Materials: 4.5" O.D. Pipe, 2 2-foot sections

2 Clam Shells, provided by BP

2 sets of end caps for the clamshells

Hose Clamps

Silicone Sealant

VpCI-433

VpCI-422

VpCI-417

Methanol

VpCI-658M

Method: Environmental Chamber, 105° F and 100% Relative Humidity (RH)

Procedure:The following procedure was followed:

1. Two 2-foot sections of 4.5" plain carbon steel pipe were obtained from a local distributor.
2. The pipe was soaked with VpCI-433 to remove residue on the exterior of the pipe.
3. Next the pipe sections were rinsed with Deionized water to remove the VpCI-433 and any coating that may have been dissolved.
4. VpCI-422 was used to remove any oxides from the surface of the pipes, and the pipes were neutralized with VpCI-417.
5. The pipes were rinsed with methanol to remove the presence of any VpCIs from the VpCI-417.
6. Next the pipes were loaded into the clam shells and tightened using pipe clamps
   1. Pipe clamps were utilized since the metal clamps provided were not reusable
7. Pictures were taken of the tubes showing that they were clean and corrosion free prior to be placed in the clam shells.
8. Plastic end caps were affixed to the clamshells and both ends were sealed shut.
   1. One of the plastic end caps on the parts were clear to allow visual inspection of the portion of the tube extending past the foam.
   2. The end-caps were sealed and silicone sealant was applied to one end cap, the opaque end cap, to prevent water from flowing into the system
9. A 3/16" hole was drilled into one of the clamshells down to the pipe.
10. Approximately 45cc’s of VpCI-658M was injected into the clamshell via an Ecoair canister.

1. A screw was then inserted into the hole to prevent leakage
2. The two clamshells were allowed to condition for 24 hours prior to testing.
   1. The systems were allowed to condition, as they were tested in an accelerated chamber and both parts would have failed before the VpCIs would have
   2. migrated to protect the entire clamshell.
3. This was necessary due to the severity of the test conditions, and to provide accurate test results.
4. The test systems were inspected periodically and removed after 200 hours.
5. The tubes were removed from the clam shells, inspected, pictures were taken and a report was written.

Results: The following results were found:

DNF = Did not fail during test

Conclusion: VpCI-658M provides excellent corrosion protection to carbon steel pipe encased in the foam and would most likely have lasted much longer.

Project #: 03-021-1325

Estimated Cost of Project: 16.0 Hours

To: Patrick Laird, MRO Sales

For: Elizabeth Whalen, BP

From: Brian L. Wuertz

Date: 01-31-2003

cc: Boris Miksic

Anna Vignetti

Art Ahlbrecht

Rita Kharshan

Cliff Cracauer

Vanessa Schultz

Bob Boyle