Corrosion Control at VMT Dr. Rust, Inc. Corrosion Control at VMT - - PowerPoint PPT Presentation
Corrosion Control at VMT Dr. Rust, Inc. Corrosion Control at VMT R. Heidersbach Dr. Rust, Inc. R. Heidersbach K. Prakash R. Guise January 17, 2013 Emphasis of Project Objective not to second guess Objective is an assessment of
guess
assessment of what was seen and obvious reliability issues that need to be addressed
and RCAC
– Prevent corrosion-related environmental damage
– Only for systems that can cause oil pollution
– Corrosion control efforts – Tanks, piping, berths and related equipment
– Direct contractor to PWSRCAC – Pipes and corrosion inhibitors
– Tanks – Coatings – Berth facilities
– Cathodic protection
9/20/2012 Board Meeting PWSRCAC
Alyeska PSC
Coffman
Baker Hughes PWSRCAC
Corrosive Environments
– Largest volume of potential pollutants largest pollution risk
– Safety – Perhaps equal in operational priority, but less likely to produce pollution
– Most corrosive liquid environment
Equipment
– Most likely to leak – Pitting corrosion most likely corrosion-related leak initiator
– At waters edge
– Buried – Hard to inspect – ECDA coming standard/requirement
– Large volume of oil – Easy to inspect – Expensive internal inspections
– Requests for and analysis of documentation
– Documents review -- Alyeska’s Anchorage office
– Monday – Admin, safety, security, document requests, facilities access requests – Tuesday – Look at Berth 4, tanks, CP, piping, fire foam systems – Wednesday – Look at Berth 5 and other VMT locations, – Thursday – Exit briefing
– Injected batches on 2-week intervals
– Inserted/removed twice per year – Standard weight loss and pit depth report
and effectiveness of corrosion inhibitors
– External in “deadleg” locations – Now part of Alyeska T-500 tank inspection protocol (2012 paragraph additions)
efforts
concern
experienced some corrosion
– External in “deadleg” locations – Now part of Alyeska T-500 tank inspection protocol (2012 paragraph additions)
– Possible exceptions are roof and vapor recovery systems which were not considered in this project’s efforts – Need to review summer 2012 inspection results
now included in Alyeska procedure
– New section 3.4 on Fire Foam System added early 2012
– Follow strictest industrial/regulatory practice
– ECDA
Direct Assessment Methodology
– Questionable continuity
continuity at joints
– stray current – Questionable cathodic protection beyond the first joint
Direct Assessment Methodology
future
locations
– Evolving methodology – RBI-related
depolarization based on measurements in August 2012
– Soil side only?
the environment
– Identify/measure worst corrosion in the system
coupon—not the system
– Deadlegs – Crevices – MIC – Identify when corrosion occurred
exposure data indication of effectiveness
exposures to ID trends in corrosion rates
interpret
– Contractor/Alyeska personnel – Problemsresolution of problems
corrosion found/repaired with no leaks into the environment
Corrosion near unpainted welds on insulated piping.
Photograph by T. Kuckertz, PWSRCAC staff member, May 29, 2008 at the VMT Ballast Water Treatment Facility
Alyeska inspection
inspect selected locations
– Crude oil piping – Maximum pitting 70%+ wall loss – Sleeve repairs
Alyeska survey
Crude Header External Condition Survey (2012)
Good news
corrosion
– Before leaks
Concerns
Questions
corrosion occur?
sooner?
– 3rd year of inspection program – Previous years did not emphasize over-water locations
This is good news—inspection/maintenance has occurred
full of water on August 7 and again on August 8
full of water on August 7 and again on August 8
water on the pipe?
locations several times each year
report moisture to Alyeska decision makers
water on the pipe?
locations several times each year
report moisture to Alyeska decision makers
locations where a contractor pulling corrosion coupons gains access to the pipe twice a year.
these “dry” locations?
– May lead to melt water intrusion due to high snow loads in some locations at VMT
Slide from 2006 RCAC presentation Illustrates problems associated with localized corrosion inspections Best practice—100% inspection
inspection options ASAP (as soon as possible)
VMT should
– Emphasize inspection of above-water piping systems – Repair damaged external jacketing (weather proofing)
corrosion contractors
procedures
– Time to schedule/fund/install
external corrosion
lines
– Digging – Estimates as to where most corrosion has occurred.