Study of Cathodic Protection in an Air Crossing

Abstract

This paper presents a cathodic protection diagnosis in an air crossing that is in electrical contact with a 5-way right of way, which maintains a perpendicular trajectory to the right of way. The development of this work is considered an analysis of the corrosion level in the main pipeline, which is supported on mochets and crossbars, during the cathodic protection inspection, the electrical potential is monitored along the air crossing and at strategic points of the crossed pipelines, in order to identify the sites where the electrical link is located. On the other hand, the potential ON was measured in the posts, which are located at the point closest to the right of way; the potential measurements show that the DDV ducts are maintained above -850 millivolts belonging to the B-1, B-2, B-3, B-4 and B-5 pipelines. However, an ON-OFF cutting cycle from nearby cathodic protection systems is reflected in the pouches at points P10, P-7 and P-1. However, the cathodic monitoring in the pipeline A and the pipeline B, allow to identify that in the points P-6 and P-10 the potentials of the pipeline A and the pipelines B-2, B-3 respectively, which present potentials comparable with an ON-OFF cycle, which indicates an electrical contact with cathodic protection that meets the criteria of -0.85 volts of NRF-047-PEMEX-2007, as well as the mochettes at points P-1, P-2 and P-3 maintains electrical contact with the pipeline A, caused by the deterioration of the neoprene, causing a lack of insulation.