Pipeline Coating Condition Assessment and Installation Assessment, San Nicolas Island
Abstract
This report documents the efforts of the Naval Facilities Engineering Service Centers (NFESC) Coating Specialists response to a request by the Mechanical Systems Branch (Code 231) of NFESC to perform a pipeline coating condition assessment and an installation assessment. Findings from NFESCs assessments are as follows: A) San Nicolas Island rock and soil produced coating scratches equivalent to 60 - 400 grit sandpaper, B) Field repairs contained surfaces with flash rusting and most likely contain high levels of chloride ion contamination, C) The fully cured coating has a Shore A Hardness value of 95, D) The pipe has a 1 - 2 mil grit blasted anchor profile, E) The coating has poor gouge resistance (manufacturers data), F) The coating has poor impact resistance (manufacturers data) G) Average coating loss from taber abrasion was 345 mg and represents low abrasion resistance, H) Coating loss from simulated abrasion over a 900 ft horizontal pull ranged from 50 - 100 mils (0.97218 - 1.94436 gram coating loss/in2), I) Coating has an average cohesive strength of 716 psi (maximum shear bond strength), and J) A putty knife using hand pressure gouged and removed coating chunks (cohesive failures). If the applied coal tar urethane has greater than 700 psi adhesion and field repairs contain less than 7 ug/cm2 of chloride ion contamination at the pipe/coating interface, then several options may be used to increase the coatings abrasion and gouge resistance: A) Apply either a chemically compatible adhesive or a layer of the coal tar urethane over the existing coating system followed by round polyethylene sheet, B) Apply either a chemically compatible adhesive or a layer of the coal tar urethane over the existing coating system followed by a hot applied shrink sleeve, and C) Apply an additional layer of coal tar urethane containing a high loading of either sand or aluminum oxide.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1999
- Accession Number
- AD1072447
Entities
People
- C. D. Gaughen
Organizations
- Naval Facilities Engineering Systems Command