Overcoming temperature and cooling issues, and the availability of robust turnkey solutions, are vital in the modern enclosures market, reports Susan Fearn Ringsell.
Many of the most significant process control and instrumentation projects of current times involve installing plants in extreme locations: dealing with the intense cold of an Arctic environment demands high-performance insulation.
Perhaps the single most significant trend is the purchasing of systems that are assembled in the factory and delivered ready for hook-up.
Enclosure quantities for such projects often run into hundreds. However, Intertec has regularly seen an increase in orders for assembled systems in much smaller quantities – down to quantities of just one.
The key is in understanding the unique demands of the application and choosing an enclosure that is designed to meet those requirements
Charlene Loriot, marketing manager, Legrand UK & Ireland’s industrial range
Gavin Faulkner, sales manager at Intertec Instrumentation, explains: “Labour in the factory costs significantly less than in the field – and much less than labour in remote locations such as offshore – so there can be a strong economic case. Self-assembly also requires careful storage, gathering and transport to the location for installation.”
Quality of assembly and inspection/testing in a workshop with its superior tools and facilities is also invariably higher than in the field.
And there is a single point of responsibility for the design – making sure it integrates without problem, meets the specification and has the right certification.
Key issues
There are further reasons for the rise of turnkey solutions, explains Faulkner: “One is cost of procurement. Another reason is the ability to more easily perform added value services to the factory-assembled enclosure system.”
This portion of Intertec’s overall business has more than doubled in size recently and well over half the enclosures shipped are now in the form of turnkey instrumentation systems.
“Examples include shipping complete and tested skid-mounted systems, fully-equipped analyser shelters, and perhaps the most complex projects of all – sophisticated turnkey large-scale plant buildings such as remote instrumentation enclosures (RIEs) which are being used to decentralise control and instrumentation equipment into the field, close to the process,” explains Faulkner.
With the increasing number of requests for quotation that Intertec receives, it’s clear that many engineers have limited understanding of the standards involved.
Specification may well be heavily dependent upon the application and the specific requirements of that environment.
Charlene Loriot, marketing manager for Legrand UK and Ireland’s industrial range, comments: “The key is in understanding the unique demands of the application and choosing an enclosure that is designed to meet those requirements.”
Jim Collins, co-owner of South Penn Resources, a company that creates containment, adds that traditional coatings are frequently inflexible when cured and can crack along with the concrete – requiring constant upkeep and maintenance.
“This deficiency can lead to cracks or holes developing in both the substrate and the coatings, which can compromise primary containment, thus requiring secondary containment,” says Collins.
However, the formulations of tough, monolithic, flexible coatings such as polyurea are now resolving this issue for contractors, engineers, and facility managers.
“The basic GRP sheet material used in Intertec’s enclosures has a very high thermal resistance compared to metal, with an efficiency that is over 1,000 times better,” explains Faulkner.
“GRP sheets are also fabricated easily in composite sandwich forms, enclosing high-performance insulation.”
Longer lifecycles
Lifecycles are being driven by the demands of challenging upstream projects – such as platforms in the North Sea – where the risk and cost of equipment failures and downtime can be huge.
Intertec employs a specially developed gel-coat of unsaturated polyester resin, matching the properties of GRP, which is applied as a spray before the panel is fully cured.
The polyester resins of the gel-coat and panel form a chemical bond; after curing, the coating provides an extremely durable, but flexible, surface finish with a high resistance to weathering and hydrolysis loads. The gel-coat is typically applied as a 500 micrometre-thick layer.
The problems of producing enclosure solutions for remote locations are exacerbated by the lack of reliable electricity supply.
One key trend that has impacted design and development is the ability to customise enclosure design
Employing passive cooling technology has been an answer for many of these systems, but this tends to work well only in arid climates with large daily temperature swings.
Intertec employs two main techniques: micro-pumps powered by small solar panels to improve circulation of cooling media; plus augmentation of the performance of the cooling media by means of cooler or chilled water.
A notable trend is the increasing requests for cabinets and shelters with fire resistance, for housing critical resources in plants or parts of emergency shutdown systems.
Without a global standard in the instrumentation industry for fire resistance, Intertec has seen requests from large users for conformance to fire resistance classifications such as F60 or F120.
“One key trend that has impacted the design and development of our range,” says Loriot “is the ability to customise enclosure design.”
Legrand now offers powder coatings for both the enclosure and wall mounting lugs – from a choice of up to 180 RAL/colours; a fitting service in which customers can specify the exact accessories required inside the enclosure; as well as a custom-drilling offering.
When developing enclosures, two aspects need addressing: temperature within the cabinet and availability of more robust solutions that cope with challenging operating environments.
These remain critical factors for engineers to consider when embarking on the specification process.
