Corrosion of Underground Low Pressure Gas Pipelines under Alternate Current

Coatings and Cathodic Protection for Underground Pipelines - What a Corrosion Engineer Should Know

Coatings control corrosion by providing a barrier against oxygen and water. Although coatings are extremely effective, all organic coatings are semi-permeable to O2 and water. The water permeability coefficient of fusion bonded epoxies, one of the best coating systems, is approximately 10 gms/mil/24 hours, but minimum concentration of oxygen and water that can start the corrosion process is 10 ...

Metallurgical Analysis of High Pressure Gas Pipelines Rupture

On 6 July 2004, two parallel-running gas pipelines (18-inch and 24-inch diameters), in the main transmission network of SNGPL (a gas company in Pakistan) were ruptured. The ruptures occurred in the early hours of the morning about 8 miles downstream of the compressor station AC-4. The ruptures were indicated by the increased gas flow at the outlet of AC-4 [1], first at about 0648 hours and then...

Collapse of Corroded Pipelines under Combined Tension and External Pressure

In this work, collapse of corroded pipeline under combined external pressure and tension is investigated through numerical method. Axially uniform corrosion with symmetric imperfections is firstly considered. After verifying with existing experimental results, the finite element model is used to study the effect of tension on collapse pressure. An extensive parametric study is carried out using...

Cathodic Corrosion Protection of earthburried Pipelines

Inhibition of Pipelines Corrosion Using Natural Extracts

The present work is aimed at examining carbon steel oil pipelines corrosion using three natural extracts (Eruca Sativa, Rosell and Mango peels) that are used as inhibitors of different concentrations ranging from 0.05-0.1wt. %. Two sulphur compounds are used as corrosion mediums. Weight loss method was used for measuring the corrosion rate of the carbon steel specimens immersed in technical whi...