Why independent conduit testing is needed

Performance requirements for coated conduit are crucial.

02/17/2014


For years, all available brands of polyvinyl chloride (PVC)-coated galvanized conduit met the same UL 6 standards and carried an identical UL label relating to safety conformance. Yet, it was apparent in the marketplace that not all brands performed the same. With products like coated conduit, adhesion of the coating is crucial. If the coating bond is broken, a void is created and moisture penetrates to the metal substrate and corrosion is actually accelerated.

Figure 3: In this polyvinyl chloride (PVC)-coated conduit specimen, the coating adhesion has failed. This conduit sample was exposed for approximately two days in the hot water immersion test. Once the cuts are made, the PVC coating is easily removed by pFigure 4: In this polyvinyl chloride (PVC)-coated conduit specimen, acceptable adhesion is shown. Courtesy: Robroy Industries

The lack of performance requirements for coated conduit has been recognized by many companies and is gaining recognition by users. This fact is confirmed by recent discussions with consulting, specifying, and maintenance engineers at paper plants, wastewater treatment facilities, and other locations. 

Figure 5: Products verified by ETL are clearly labeled. Courtesy: Robroy IndustriesTo confirm the performance of the PVC coating, Intertek evaluated PVC-coated galvanized conduit brands solely for product performance and longevity as tested under conditions consistent with highly corrosive environments. Heat and humidity are recognized corrosion accelerators in corrosion engineering textbooks and technical documents from organizations such as the National Association of Corrosion Engineers (NACE). 

The test results provided a quantitative method to compare the relative performance of coated conduit systems in conditions typical of the corrosive application environments. The results of both tests confirm significant differentiation in adhesion performance of the PVC coated conduit available in the market and why only certain brands carry Intertek’s ETL label.


Stephanie Ellis is director of Corrosion College. She holds a basic certification from the National Association of Corrosion Engineers and is a member of the International Association of Electrical Inspectors. Corrosion College is a hands-on course that explains the process of corrosion through intensive instruction by professionals in the field of corrosion protection.



No comments
The Top Plant program honors outstanding manufacturing facilities in North America. View the 2015 Top Plant.
The Product of the Year program recognizes products newly released in the manufacturing industries.
The Engineering Leaders Under 40 program identifies and gives recognition to young engineers who...
2016 Engineering Leaders Under 40; Future vision: Where is manufacturing headed?; Electrical distribution, redefined
Strategic outsourcing delivers efficiency; Sleeve bearing clearance; Causes of water hammer; Improve air quality; Maintenance safety; GAMS preview
World-class maintenance: The three keys to success - Deploy people, process and technology; 2016 Lubrication Guide; Why hydraulic systems get hot
Flexible offshore fire protection; Big Data's impact on operations; Bridging the skills gap; Identifying security risks
The digital oilfield: Utilizing Big Data can yield big savings; Virtualization a real solution; Tracking SIS performance
Getting to the bottom of subsea repairs: Older pipelines need more attention, and operators need a repair strategy; OTC preview; Offshore production difficult - and crucial
Applying network redundancy; Overcoming loop tuning challenges; PID control and networks
Driving motor efficiency; Preventing arc flash in mission critical facilities; Integrating alternative power and existing electrical systems
Package boilers; Natural gas infrared heating; Thermal treasure; Standby generation; Natural gas supports green efforts

Annual Salary Survey

Before the calendar turned, 2016 already had the makings of a pivotal year for manufacturing, and for the world.

There were the big events for the year, including the United States as Partner Country at Hannover Messe in April and the 2016 International Manufacturing Technology Show in Chicago in September. There's also the matter of the U.S. presidential elections in November, which promise to shape policy in manufacturing for years to come.

But the year started with global economic turmoil, as a slowdown in Chinese manufacturing triggered a worldwide stock hiccup that sent values plummeting. The continued plunge in world oil prices has resulted in a slowdown in exploration and, by extension, the manufacture of exploration equipment.

Read more: 2015 Salary Survey

Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Society for Maintenance and Reliability Professionals an organization devoted...
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.
This article collection contains several articles on the vital role that compressed air plays in manufacturing plants.
This article collection contains several articles on the Industrial Internet of Things (IIoT) and how it is transforming manufacturing.
This article collection contains several articles on strategic maintenance and understanding all the parts of your plant.
click me