EXPERT TIP #23 – COUPONS FOR THE CORROSION INDUSTRY
In the corrosion industry, “coupons” are used in the fight against corrosion, but the term coupon is used interchangeably in corrosion monitoring. In fact, there are two general types of corrosion monitoring coupons used for entirely different purposes.
Cathodic Protection Coupons
These metallic coupons of a specific size are used to assess the effectiveness of cathodic protection (CP) systems. They are typically made of the same metal as the structure being protected. CP coupons are buried adjacent to the structure under protection, and a coupon cable or cables are routed to an above-ground test station where CP professionals can conduct CP testing. The CP coupon, which is bare metal, represents a coating defect or “holiday” in the structure’s protective coating
EXPERT TIP #32 – MAKING EFFECTIVE CATHODIC PROTECTION CONNECTIONS TO A STRUCTURE
During a typical cathodic protection (CP) field survey, the CP technician must make effective electrical connections to the structure under test and other metallic components.
Often, the technician will encounter an existing above-ground test station where a conductor (cable) is permanently attached to the structure under test and the other end is terminated to the test station panel. In this case, the connection to the structure is already made and is typically effective.
EXPERT TIP #31 – KNOWING CP SYSTEM & STRUCTURE DETAILS
When an existing CP system requires review and/or testing, the work will be to determine if the system is working correctly and/or to troubleshoot system issues. Before the fieldwork starts, it is important to review any available documentation or historical data describing the type of CP equipment and itsperformance.
EXPERT TIP #30 – THE IMPORTANCE OF DIELECTRIC COATINGS ON PIPELINES
Dielectric coatings play a crucial role in protecting buried pipelines from various forms of corrosion and degradation.
EXPERT TIP #29: THE IMPORTANCE OF ELECTRICAL ISOLATION FOR BURIED PIPELINES
EXPERT TIP #28: PREVENTING CORROSION OF CATHODIC PROTECTION EQUIPMENT
Cathodic protection prevents corrosion of pipelines, storage tanks, and other critical buried or submerged infrastructure assets that support our daily lives. When used effectively, cathodic protection (CP) and coatings are the best methods for preventing subsurface corrosion.
The Impact of the Mega Rule on Cathodic Protection
Cathodic Protection is essential for preventing corrosion on underground and submerged metallic structures such as pipelines. The introduction of the Mega Rule by the U.S. Pipeline and Hazardous Materials Safety Administration (PHMSA) has far-reaching implications for Cathodic Protection practices, extending federal oversight to an additional 400,000 miles of pipelines and bolstering safety protocols.
EXPERT TIP #27: THE INS AND OUTS OF WIRING IN CATHODIC PROTECTION
The Use of Wire in Cathodic Protection
In the Cathodic Protection (CP) industry, as with many others, we use a vast assortment of electrical
devices with significant variations of operating ranges. For instance, reference electrodes operate at less
than one volt with currents measured in micro-amps. At the same time, large CP power supplies can
have system voltages exceeding 450 volts and up to 1,000 amperes of DC output. These electrical
devices all utilize wire of varying sizes and operating requirements, and the wire sizes can be small as
0.01” (10 thousandths) diameter to over 0.46” diameter.
EXPERT TIP #26: USE AND MISUSE OF AN OHMMETER
Purpose of an Ohmmeter
The modern portable digital multimeter (DMM) is an indispensable tool with many functions and
features. Typically, a DMM is used to measure AC and DC voltages and currents. In addition to these
features, they also include an Ω (OHM) function to measure the electrical resistance between two
points.