Server maintenance is scheduled for Saturday, December 21st between 6am-10am CST.

During that time, parts of our website will be affected until maintenance is completed. Thank you for your patience.

Menu
Search
Filters
Close
Menu

Methodology to Estimate Edge Effect on Direct Current Cathodic Protection Coupons

Picture for Methodology to Estimate Edge Effect on Direct Current Cathodic Protection Coupons
Available for download

A model was developed to study the effects on the CP coupon current density and interpretation of the CP coupon data for a given holiday. The model results indicate that the most dominant factor affecting coupon is the size, followed by corrosion potential.

Product Number: 51317--8976-SG
ISBN: 8976 2017 CP
Author: Pavan Shukla
Publication Date: 2017
Industry: Corrosion Monitoring and Control
$0.00
$20.00
$20.00

Direct Current (DC) Cathodic Protection (CP) coupons are widely used in the pipeline industry to monitor CP potential and estimate current densities at the holidays. Various DC coupon shapes include flat metal surface embedded in an insulating plane long and small rods and stubby cylinders. Of these flat coupons including rectangular and disk shapes are most widely used as they are assumed to be representative of the holidays at the pipe surface. However flat coupons embedded in insulating plane are prone to current density measurement errors due to edge effect. The current density at the coupon’s edges is expected to be several times higher than the center of the coupon. Because the holidays on pipeline are surrounded by coated surfaces the current density distribution at the coupons is expected to be different than the holidays. Specifically a holiday surrounded by the coating will have lesser degree of edge effect due to coating thickness compared to the coupon surface. This paper investigates edge effect on the CP coupon current density and identified a methodology to interpret the coupon current data at the holiday surface.

Keywords: coating holidays, cathodic protection, test coupons

Direct Current (DC) Cathodic Protection (CP) coupons are widely used in the pipeline industry to monitor CP potential and estimate current densities at the holidays. Various DC coupon shapes include flat metal surface embedded in an insulating plane long and small rods and stubby cylinders. Of these flat coupons including rectangular and disk shapes are most widely used as they are assumed to be representative of the holidays at the pipe surface. However flat coupons embedded in insulating plane are prone to current density measurement errors due to edge effect. The current density at the coupon’s edges is expected to be several times higher than the center of the coupon. Because the holidays on pipeline are surrounded by coated surfaces the current density distribution at the coupons is expected to be different than the holidays. Specifically a holiday surrounded by the coating will have lesser degree of edge effect due to coating thickness compared to the coupon surface. This paper investigates edge effect on the CP coupon current density and identified a methodology to interpret the coupon current data at the holiday surface.

Keywords: coating holidays, cathodic protection, test coupons

Product tags
Also Purchased
Picture for Cathodic Protection Coupon Use for Buried Piping in Plant (i.e. Complex) Facilities
Available for download

Cathodic Protection Coupon Use for Buried Piping in Plant (i.e. Complex) Facilities

Product Number: 51317--8824-SG
ISBN: 8824 2017 CP
Author: Douglas Gilroy
Publication Date: 2017
$20.00

Measurement and interpretation of cathodic protection data in plant facilities present challenges where mixed metals are electrically continuous with the protected structure. This paper address some of the confusion and important aspects when using coupons for buried piping in mixed-metal circuits.
Picture for 05039 Field Tests on an Advanced Cathodic
Available for download

05039 Field Tests on an Advanced Cathodic Protection Coupon

Product Number: 51300-05039-SG
ISBN: 05039 2005 CP
Author: Frank J. Ansuini, Electrochemical Devices Inc.; James R. Dimond, Dimondale Company Inc.
$20.00
Picture for 98677 CRITERIA FOR DESIGN OF CATHODIC
Available for download

98677 CRITERIA FOR DESIGN OF CATHODIC PROTECTION PROBES WITH COUPONS

Product Number: 51300-98677-SG
ISBN: 98677 1998 CP
Author: George Nekoksa
$20.00
Categories
Industry
Recently viewed
Popular tags
View all

Association for Materials Protection and Performance

© AMPP All Rights Reserved.
Membership Terms of Content Use
Contact Customer Support