Cathodic Protection Requirements for Military Projects

Michael A. Wallace, P.E. Electronics Engineer NACE Cathodic Protection Specialist Engineering Division US Army Corps of Engineers Mobile District Office: FAX: CESAM-EN-DR 109 Saint Joseph St. Mobile, AL

Corrosion is a major Economic, Environmental, and Safety Problem which adversely affects our Nation, as well as many of our military facilities. Impact of Corrosion

Corrosion is the deterioration of a material, usually a metal, because of a reaction with its environment. What is Corrosion?

Typical Corrosion Cell TUBERCULAR BUILDUP OF RUST

Types of Corrosion Cells Dissimilar Metal Cell Concentration Cell Differential Aeration Cell Stray Current Cell Stress Cell New Pipe and Old Pipe Cell Motion Cell Combination Cell Temperature Cell

Corrosion Control must be properly addressed during the design, installation, and subsequent operation of systems adversely affected by the corrosion process. Corrosion Can Be Controlled

Corrosion Control Methods Protective Coatings Design Environmental Control Material Selection Cathodic Protection

Protective Coatings Normally first line of defense against corrosion: provides barrier between a corrosive environment and the structure. No coating is perfect and consists of holidays (voids) often resulting from improper application and/or damage. Cathodic Protection often used in conjunction with coatings to protect the holidays or voids in the coating system.

An electrical method of mitigating corrosion on metallic structures that are exposed to electrolytes such as soils and waters. Cathodic Protection:

Sacrifical Cathodic Protection Magnesium or Zinc

Impressed Current CP

Standards and Laws NACE International Standards (National Association of Corrosion Engineers) 40 CFR Part Underground Storage Tanks (UST) 49 CFR Part Transportation of Natural Gas and other Gas by Pipeline 49 CFR Part Transportation of Hazardous Liquids by Pipeline Individual State Environmental and Safety Laws

Military Criteria ETL , Cathodic Protection TM , Cathodic Protection MIL-HDBK-1004/10, Electrical Engineering, Cathodic Protection MIL-HDBK-1136, Maintenance and Operation of Cathodic Protection Systems (Draft)

Military Criteria (Cont.) Guide Specifications (Army) –UFGS 13110A Cathodic Protection System (Sacrificial Anode) –UFGS 13111A Cathodic Protection System (Steel Water Tanks) –UFGS 13112A Cathodic Protection System (Impressed Current)

ETL requires CP & Coatings regardless of soil or water resistivity for: Natural Gas and propane piping Liquid fuel piping Oxygen piping Underground storage tanks (UST) systems Fire protection piping Steel water tank interiors Ductile or cast iron pressurized piping under floor slab Underground heat distribution & chilled water piping in metallic conduit Other structures with hazardous products

Designer Qualifications Design must be accomplished by qualified personnel. ETL requires the following: – All pre-design surveys, designs, and acceptance surveys must be by a “Corrosion Expert.” –“Corrosion Expert” is a NACE Certified Corrosion Specialist, CP Specialist, or registered Professional Corrosion Engineer. –“Corrosion Expert” must have a minimum of 5 years experience in CP design and experience must be type specific.

Advantages of Adequate Corrosion Control Extended Coating and Structure Life yielding Cost Savings Protection of Environment Improved Public and Employee Safety Avoidance of costly Litigation resulting from non-adherence to Laws and Regulations

Upstream View of Rupture Crater Carlsbad, NM Explosion

Lively, TX Explosion Gas Explosion - killed 2 Teenagers Oil Company did not maintain CP system and falsified records to OPS Jury awarded over 300 million dollars to Plaintiff

Removed & Leaking UST Tank Wall Completely Penetrated Due to Pitting Corrosion

Corrosion of Steel H Piling Embedded in Concrete MacDill AFB, Florida

Summary Corrosion is costly and its effects can cause harm to our environment, as well as to human life. Cathodic Protection can effectively control corrosion. Cathodic protection is required by many laws and regulations and must be designed by qualified personnel.