Northeast Gas Operation School Thursday June 5 th

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Noel Hood
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1 Northeast Gas Operation School Thursday June 5 th Recognition and Assessment of Atmospheric Corrosion Presented by Donald A. Doubleday Jr. National Grid New England Corrosion Engineer & Team Lead

2 Contents Applicable Codes and Regulations Types of Environments Forms of Corrosion Coatings & Remediation Inspection Process Photo s, Photo s and more Photo s

3 Codes and Regulations CFR 49, Pipeline Safety Regulations Section Atmospheric corrosion Control: General Section Atmospheric Corrosion Control: Monitoring Your Companies Operations and Maintenance Manual

4 Atmospheric Corrosion Control: General Each operator must clean and coat each pipeline or portion of pipeline that is exposed to the atmosphere. Coating material must be suitable for the prevention of atmospheric corrosion. Except portions of pipelines in offshore splash zones or soil to air interfaces, the operator need not protect from atmospheric corrosion any pipeline for which the operator demonstrates by:

5 goes on to say For which the operator demonstrates by Test, Investigation, or Experience appropriate to the environment of the pipeline that corrosion will: a) Only be a light surface oxide, or b) Not affect the safe operation of the pipeline before the next scheduled inspection.

6 Atmospheric Corrosion Control: Monitoring During the inspection the operator must give particular attention to: Pipe at soil to air interfaces Under thermal insulation Under disbonded coatings At pipe supports Splash Zones At deck penetrations Over spans of water

7 Atmospheric Corrosion Monitoring Part (cont.) Each operator must inspect each pipeline or portion of pipeline that is exposed to the atmosphere for evidence of atmospheric corrosion as follows: - Once every three calendar years but not to exceed 39 months

8 Atmospheric Corrosion Monitoring: (cont.) If atmospheric corrosion is found during an inspection, the operator must provide protection against corrosion as required in

9 Atmospheric corrosion is defined as: Corrosion which causes deterioration or pitting of the pipe surface resulting from a reaction with the atmospheric environment

10 Types of Environments Industrial Acid Rain Marine Rural Salt Spray or Splash Zones Ocean or Road Salts Fertilizers w/ condensation Indoor - High Relative Humidity

11 Factors Affecting Atmospheric Corrosion Moisture Condensation Relative Humidity Dew Rain Temperature Cycling Hot/ Cold Contaminants Acidic Contaminants Alkaline materials (limestone) Chlorides affect corrosion rates

12 Forms of Corrosion Uniform Surface Rust or Pitting - General Pitting - Localized Fretting Corrosion Crevice - Intergranular Exfoliation Dissimilar Metals - Galvanic

13 Uniform Corrosion

15 Pitting

17 Fretting Corrosion

18 Crevice Corrosion

20 Exfoliation

23 Coatings Wax Tapes (primer) Minimal surface prep Paints (rust protective enamel) Minimal to medium surface prep Epoxies (curing times) Medium to extensive surface prep Cold Applied Tapes Minimal to medium surface prep Shrink Sleeves Medium to extensive surface prep Handling and storage should be in a dry place, ventilated and above freezing temps

24 Coatings Coatings are applied to protect the steel pipe from the environment. Reasons why Coatings Fail. The installation was never coated. The pipe surface was not properly cleaned prior to coating application. Initial Improper Selection of Coating for the Environment or Application. Poor workmanship NOTE: Proper SURFACE PREP is KEY to any successful application of coatings

25 Surface Preparation Minimal Surface Prep: Remove all dirt, loose mill scale, loose paint, loose rust, any other loose foreign matter Extensive Surface Prep: Suitable anchor pattern, the surface when viewed without magnification shall be free of oil, grease, dirt, mill scale, corrosion products, oxides, paint and foreign matter All Coatings must be applied in accordance with Manufacturers Specifications

26 Tools Wire brush Brushes, gloves, rags Knife, hammer, chisel Torch with regulator, hose and propane tank (shrink sleeves) Tape Wrapster machine (cold applied tapes) Power cleaning tools Abrasive blast equipment: NACE SSPC-SP2 Hand Tool Cleaning NACE SSPC-SP3 Power Tool Cleaning NACE SSPC-SP5 White Metal Blast (NACE 1) NACE SSPC-SP6 Commercial Blast Cleaning NACE SSPC-SP10 Near White Blast (NACE 2) Coating inspection tools like: Jeep (electrical test, correct settings) Wet film gauge Dry film gauge Visual

27 Inspection Process In some companies leak survey techs, customer service techs, meter readers, contractors, ect. performs the atmospheric inspections. At National Grid we utilize Walking Survey is our Primary Inspection Process, with CMS as our secondary: Soil to Air Interface Buried Meter Shut-Off Buried or Corroded Meter Piping (to outlet of meter) Coating Disbondment Never Been Painted Poor Corrosion Foreign Contacts Foreign grounds Metallic (pipe to pipe)

28 Inspection Process Fittings -Dissimilar Metals -Insulated Fitting's -Electrical or Lightning Burn Marks Meter Bar (integrity, corrosion) Splash Zones Deck Penetrations Supports (integrity, corrosion) Meter Protection (needed, poor condition) Foundation Wall (exfoliation) Hidden or Concealed Piping (inspection not complete if we don t see the wall penetration)

29 Inspection Process ADDITIONAL INSPECTION REQUIRED Need to document when addition resources are required Inspection goes beyond standard inspection Deck or Building in way Special Equipment needed. Bucket Truck, Ladder, ect. Ultrasonic Thickness Tester

38 Inspection Classification Each Company has there own set of classifications Good, Fair or Poor Satisfactory, Mild, Slight or Severe I d like to argue we need an: IMMEDIATE Spalling

39 Inspection Classification Satisfactory - a state where the component does not show signs of corrosion and/or any noticeable structural or mechanical defects. Mild (cosmetic) - degree of corrosion in which rust stains are beginning to appear and are causing cosmetic concerns. Minor cleaning and re-coating will mitigate future concerns. Applying a paint and primer system normally is sufficient to resolve mild corrosion issues. Slight - a condition in which pitting or scaling is beginning to take place. Scrapping and/or wire brushing the area to remove loose corrosion deposits and then applying a paint and primer system normally mitigate future concerns. Severe - a condition in which sufficient metal loss creates a concern for the integrity of the pipe or structural component. Corrective action may require replacement or structural reinforcement of the affected component. Nondestructive examination may be used to determine the degree of corrosion and serviceability of the component.

40 Record Keeping NEAT NEAT NEAT NEAT PLEASE

41 Soil to Air Interfaces

42 Soil to Air Interface

43 Soil to Air Interface

44 Soil to Air Interface Wet Bark Mulch

45 Buried anodeless riser, meter shut-off and meters

46 Buried Shut-offs & Anodeless Risers

47 Buried Shut-off

48 When we dug it out we found an improperly buried anodeless riser

52 Perfection Mold Shot Anodeless Riser Here is the manufacture s recommended transition point that must be above grade Here is the location of the Max Bury Depth Do Not Bury sticker