Raju Narayan Subramaniam is a practising Corrosion Engineer, with over 30 years in the field of cathodic protection and coatings. He has a basic degree in Chemical Engineering and is a Chartered Engineer, a Fellow of the Institute of Corrosion (UK) and a NACE certified CP and Corrosion Specialist.
He has been actively involved in various cathodic protection system designs and field work, including surverys, for both onshore, offshore and marine applications in the UK, Middle East, North Africa, Far East and Latin America.
He currently resides in the UK, where he works as a Consultant, in the field of cathodic protection.
He also serves as a CP instructor for various levels.
He is the current Chairman of NACE, Great Britain Section
DCVG surveys and coating repairs.
A DCVG survey is an ECDA tool to locate coating defects with good precision and provide a relative defect sizing. Voltage gradients, at coating defect locations generated by the application of a pulsed DC current, can be used to estimate the size of a coating defect along the pipeline.
Defect size is only one of the factors considered in deciding whether to excavate and repair. A number of factors affect the defect sizing and should be considered . Likewise, benchmarking defect sizes for a particular environment and depth is equally important. Coupons provide accurate benchmarking of defect sizes.
DCVG is not a measure of cathodic protection effectiveness.
An indexing to determine the severity of corrosion must be carried out as part of risk assessment after considering key factors in making a decision on excavation and repair