Innovative field shelter keeps cool.

A field equipment shelter fitted with fault-tolerant cooling is ensuring the reliability of a wireless communications link that connects instrumentation on a new gas pipeline crossing a Middle Eastern desert to the remote control room. Fabricated from tough glassfibre-reinforced polyester (GRP) materials, the shelter houses a TETRA basestation powered by solar panels - in order to function reliably in an off-grid location some 50 km from the nearest town.

Intertec's shelter employs a 'hybrid cooling' system to safeguard the 56 m2 shelter's electronics equipment, and battery power storage compartment - a Zone 1 area. The system consists of a water-based passive cooler assisted by dual-redundant electrically-powered water coolers. This approach combines the intrinsic reliability of passive cooling with active water refrigeration to increase cooling efficiency on hot days. The system can handle a cooling load of around 1.9 kW, ensuring that even during this Middle Eastern climate's summer - when ambient temperatures can climb as high as 55 °C - interior shelter temperatures will always stay below a worst-case peak of around 35 °C. At other times of the year, internal shelter temperatures are maintained far below these levels.

"Hybrid cooling for field shelters and cabinets is a major enabler for process plant operators that need to install electronics equipment in remote off-grid locations, and hostile environmental conditions", says Intertec's HVAC Project Manager, Simon Marlier. "The very high level of reliability that can be achieved by hybrid cooling, and its suitability for applications in hazardous areas, can greatly simplify many common remote and unmanned applications. Among the applications potential are wellhead control systems, SCADA stations on pipelines, battery shelters - especially for lead-acid and lithium-ion types - and off-grid mobile basestations."

The remote location means that the basestation is far from the electricity grid, and must be powered by solar energy. The passive cooling system, based on a water tank with internal and external heat exchangers, exploits the desert climate's daily temperature swing to store the coolness of the night and use it to moderate internal temperatures during the day. The water circulates around the system by natural convection, without electrical power or moving parts. This system alone manages the shelter's cooling needs during the winter months - typically keeping temperatures at around 18 - 20 °C. The two powered water coolers increase the efficiency of the cooling system during the hottest months - operating in an alternating sequence for fault tolerance - typically maintaining temperatures in the 20 - 30 °C range. Even if both water coolers were to fail, Intertec's passive system has enough cool water capacity to maintain low shelter temperatures for many days - giving maintenance staff plenty of time to access the remote site and make repairs.

The water coolers are a new variant of Intertec's novel Hybricool range that operate directly from a DC power supply - making them an efficient solution for solar-powered installations. These cooling units are specially designed to supplement passive coolers operating in process plants, with a heat exchanger element that can be installed inside the water storage tank of a passive cooling system to decrease temperature. This interior element is isolated from the rest of the externally-mounted refrigeration system, making it both an efficient and economic solution for explosion proof applications such as the battery compartment of this shelter.

Hybricool water coolers operate on the refrigeration principle. They have a closed loop system with four main components: compressor, condenser, expansion valve and coil. The coil is a heat exchanger element that can be installed inside the water storage tank of a passive cooling system to decrease temperature. The interior and exterior compartments are completely isolated from each other to stop any weather elements from entering the shelter.

Cooling efficiency is aided by the shelter's construction, which uses composite wall panels with GRP sheets 'sandwiching' an embedded 85 mm layer of polyurethane foam insulation. In conjunction with a sunshade, this delivers very stable interior environmental conditions compared with conventional metal-based shelters. Intertec's manufacturing process allows it to fabricate composite GRP panels with many different material layers. In this application, the outer GRP layers provide exceptional resistance to corrosion - as GRP does not rust or degrade in any meaningful way. A further gel-coat layer on the exterior surface provides protection against the climate's very high levels of ultraviolet light, and abrasion from dust or sand. The externally-mounted water coolers additionally feature a centrifugal sediment separator that removes dust and sand, and flaps that close when the cooler is not operational.

A passive cooling system can typically limit the maximum internal temperature of cabinets or walk-in shelters to around 10 degrees Centigrade above minimum night-time temperatures - making it ideal for applications in arid and desert climates. The addition of Intertec's Hybricool water cooler technology reduces the dependence on low night-time temperatures, opening up applications in a much broader range of climates and geographical locations.

#PAuto #Intertech 

Protecting offshore process analysers.

Shelters fabricated from glassfibre-reinforced polyester are protecting gas metering instrumentation from the harsh North Sea environment on an offshore platform upgrade project engineered by Oil & Gas Systems. Two outdoor shelters - supplied by Intertec Instrumentation - provide lightweight and corrosion-resistant protection for gas chromatograph analyzers and process transmitters mounted above new natural gas export pipelines connecting the platform to an onshore British gas terminal. The instrumentation provides critical monitoring data on gas quality as part of the custody transfer metering system.

Installed on North Sea platform

This particular platform upgrade project presented a number of challenges, including the harsh operating environment of the southern North Sea, and the space and weight restrictions of adding the new facilities onto a working platform. Metering systems for fiscal, allocation and custody transfer applications are a significant part of the systems integration work of Oil & Gas Systems (OGS) - which has a reputation for being able to rapidly design and build efficient solutions for complex project requirements.

Glassfibre-reinforced polyester (GRP) materials were specified to protect the instrumentation. This allowed weight to be reduced significantly compared with metal shelters. GRP construction also provided excellent protection against both the harsh weather in the offshore location, and the local environmental conditions. Intertec Instrumentation was selected to build the custom GRP shelters because of previous good experience of working with them on projects, including shelters and enclosures already installed in the same gas field.

The lightness of GRP compared to steel helped to reduce the size and weight of the metalwork structure that mounts the shelters directly above the export pipelines. The location - in the middle of a crowded working platform - also presented access difficulties. So, natural ventilation according to IEC EN DIN 61285 was specified. This eliminates routine maintenance visits that would be required with other shelter ventilation approaches such as fans or an HVAC system.

Gas chromatograph inside shelter

To support natural ventilation for safe operation in the hazardous environment, Intertec supplied explosion-proof heaters and installed louvre panels at the top and bottom of shelter walls. This maintains the interior environment a few degrees above ambient temperature, and ensures an efficient convection cycle to meet the air change requirements of OGS. All of the shelter fittings, apart from the finned aluminium bodies of the heaters, are fabricated from 316 stainless steel for corrosion resistance - including the panic bar door opening mechanism.

"It can be a significant challenge to add new facilities into existing processing plants, and especially so when they are located offshore," says Anthony Dingle, OGS's Sales Manager. "Intertec's ability to design and build custom enclosure solutions was a big help to us in meeting the design constraints of this complex and fast-track offshore instrumentation project."

In total, two walk-in shelters and two large cabinets were built by Intertec to meet the custom shape, size and weight constraints. Each shelter houses an identical instrumentation system including pressure reduction sample conditioning equipment, a Danalyzer gas chromatograph, Rosemount pressure transmitters, calibration facilities and various safety devices and accessories. The two cabinets house cylinders to supply the required gas for calibration purposes, along with associated pressure regulation, measurement instruments, tubing connection and flow control components.

The GRP material used by Intertec to build the shelters and cabinets is a proprietary multi-layer composite with moulded GRP panels enclosing polyurethane foam insulation, protected by gel-coated surfaces.

Shelter under construction in assembly facility

This composite material has a very high thermal resistance, reducing the amount of energy required to heat equipment. A further benefit of Intertec’s approach to shelter fabrication is an advanced gel-coat, which is applied in a much thicker layer than alternatives such as paint. It protects against ultraviolet (UV), and is highly effective against abrasion. It offers exceptional environmental protection and resistance to ‘corrosion’ (GRP does not rust or degrade in any meaningful way), allowing maintenance-free lifecycles of 30-40 years - more than enough to meet the anticipated cease of production date for the platform.

The gel-coat also incorporates a unique nanotechnology treatment that provides conductivity to dissipate static electric charges safely to ground - protecting against sparking in hazardous areas. Developed for Intertec by BÜFA, the coating employs single-wall carbon nanotubes (SWCNTs) to provide conductivity. Because the SWCNTs are only around 1-2 nanometres in diameter, they enhance surface smoothness. The gloss retention after accelerated weathering tests of this surface is some 50% better than the previous coating technologies used. This technology is behind the significant improvement in resistance to UV of Intertec's shelters. Previously, exposure to high UV levels over the long term could lead to surface roughening - which is sometimes referred to as 'chalking' or 'frosting'. Intertec's weathering tests have demonstrated that the new coating will withstand extended exposure to very high UV levels - providing hitherto unachievable protection for GRP field enclosures destined for ultra-harsh environments such as offshore platforms, deserts and Arctic environments.

#PAuto #Oil_Gas #Intertec_Insts @OGScompanies 

Keeping it hot!

Hazardous area certified heaters deliver high temperatures in small form-factors

Intertec's new Hot Box for outdoor process sampling applications can deliver high temperatures up to 150°C/300°F in compact footprints. The new hot boxes employ a combination of conduction and convection heating assisted by a novel air circulation system.

Protective enclosures are usually necessary for analyzer applications, and are a major contributor to overall costs. The compact hot boxes make it possible to provide elevated temperature environments for sampling systems in small form factors, This greatly simplifies installations close to the process lines being tested - to minimize sample lag time and substantially reduce the hidden costs of analyzer installations such as heated sample lines.

For many instrumentation applications in chemical and petrochemical plants, and especially for analyzer sample conditioning systems, it is essential to maintain an elevated temperature in order to prevent condensation or crystallisation of the media and corresponding inaccuracy of results. Complete insulation of measurement and analysis stations is rarely possible due to requirements for maintenance and calibration. Intertec's easy-access hot boxes provide an efficient heating solution thanks to the way they are constructed, using high-performance insulation sandwiched between sheets of GRP (glassfiber reinforced polyester). All of the materials have low thermal conductivity, and the sandwich construction means that enclosures can be fabricated using bonding techniques, avoiding the 'thermal short cuts' between inner and outer shells that metal enclosures and metal fixings create. The overall thermal insulation of a sandwich-construction GRP enclosure is typically more than twice as good as a steel enclosure with the same insulation thickness, and provides a highly stable environment for maintaining elevated temperatures. Among many applications, the hot boxes are helping plant operators to implement the monitoring and analysis required to meet new flare stack combustion rules.

The new hot boxes use electric heaters that have a flat side for conductive heat transfer, and a finned side for efficient heat transfer to the internal atmosphere using convection. The conductive face of the heater is attached to an aluminium plate. The sampling equipment is assembled onto a second detachable plate, which bolts onto the heated plate with the assistance of thermal transfer paste for optimal heat conductivity. The heaters are designed for hazardous area (potentially explosive) applications and employ positive temperature coefficient or PTC cartridges. As their electric resistance increases with rising temperature, the heaters are self limiting, ensuring that the surface temperature will never exceed the maximum temperature of the listed temperature class. Intertec's electric heating systems meet an exceptional range of hazardous area approvals including IEC, ATEX, CSA/NRTL, EAC, and many other national certificates for countries including China, Brazil and South Korea.

The exact temperature inside the hot box is controlled by Intertec's explosion proof smart controller, which provides programmable digital PID (proportional-integral-derivative) control. The temperature sensor for the controller can be mounted at the optimum position in the enclosure to ensure accurate control.

As the style of self-limiting heater used reduces heat output as temperature increases, Intertec has designed a novel feature to improve operational performance. A processing plant's instrument air service can be connected to provide a very low flow, which is introduced into the enclosure via perforated tubing that releases the air between the fins of the heater(s). This air flow continually moves the warmer air away from the heater, which as a result then maintains a higher heat output. With the heating system running at a higher rate, hot temperatures can be achieved both more quickly and very evenly throughout the enclosure's interior, and measurement cycle times can be reduced. Hot Box enclosures will also support purging if required.

In this way, Intertec can make hot boxes capable of providing certified hazardous area electric heating for temperatures up to 150°C/300°F in small footprints, complete with doors for simple maintenance and operator access. These highly insulated GRP hot boxes can be designed to be completely weather resistant, allowing large savings to be made in the installation and ownership costs of process analyzers.

Another major possibility of Intertec's GRP-based hot boxes is shape optimization. The construction techniques used for GRP make it simple to create special shapes - further simplifying online analyzer and sampling applications located close to the process.

#PAuto #Intertec

Protecting remote I/O installations.

Intertec is launching a range of tough field enclosures for housing remote I/O and other control and instrumentation electronics, featuring compact passive cooling to dramatically reduce costs of ownership. The new enclosures help EPCs and processing plant engineers to eliminate the need for large and costly plant buildings such as satellite instrument houses or remote instrument enclosures - which often need to be air conditioned and blast- and fire-resistant.

Fabricated from GRP (glassfibre reinforced polyester) materials, the enclosures provide rugged dust- and water-proof environments to protect remote control equipment located deep inside processing areas. Developed at the request of clients, the enclosure concept simplifies the roll-out of more versatile distributed control architectures containing field equipment such as software-configured I/O, IIoT networking and PLCs. The advance can allow field control equipment enclosures to be assembled and sealed in the factory - an efficient and cost effective process - avoiding the need for opening and exposure to dangerous local conditions at the site during installation and operation.

The ability of Intertec GRP enclosures to be fabricated with embedded insulation (a monolithic sandwich with layers of GRP sheet enclosing insulation) is a major virtue. Insulation is commonly required because modern remote I/O applications use sensitive electronic devices, with lifetimes and reliabilities that are drastically reduced by overheating. Efficient insulation helps protect against temperature extremes. This is one reason why the simple steel cabinets widely used for cabling-related field junction boxes are not adequate for some of the more sophisticated remote I/O applications now being deployed.

Because of the electronic devices used, some form of cooling may also be required. If power is available at site, this can be in the form of conventional fan cooling. However, the temperature stability of highly insulated GRP boxes also makes it possible to efficiently exploit passive cooling techniques which require no electricity and have no moving parts - also making them suitable for deployment in hazardous areas. A tank of water plus a heat exchanger utilise the coolness of the night to moderate interior temperature during the day.

As many advanced remote I/O applications will - by their nature - be compact and small, Intertec has designed new passive cooling systems for smaller-sized cabinets and enclosures. These include a passive cooling system with a heat exchanger that doubles as a sunshade. The performance of the passive cooler can also be boosted by a small active element – such as a water cooler. Intertec can fabricate passively cooled field protection systems like this in enclosure and box sizes down to around 40 litres in volume.

 #Intertec #PAuto

New enclosures give harsh environment protection.

The launch of new Type 4X certified GRP-based enclosures and cabinets from Intertec provide harsh environmental protection for hundreds of outdoor applications.

 Type 4X enclosures tested using
powerful water jets

The new range adds many more standard enclosure and cabinet sizes to the Type 4X rated choices available - all of which offer the exceptional anti-corrosion and insulation properties of Intertec's composite-GRP (glassfibre reinforced polyester) construction. Moreover, the choices now extend to custom GRP enclosure shapes and sizes; this service allows engineers to optimise size and shape to precisely suit equipment content and layout, and minimise surface area - thereby securing optimum thermal performance.

Intertec specialises in enclosures for outdoor applications, which are all fabricated using advanced GRP materials. GRP-based Type 4X enclosures are ideal for protecting field-based electrical and instrumentation equipment sited in marine and coastal areas, where the presence of salt in the atmosphere can severely damage traditional metal enclosures and shorten their service life significantly. Intertec’s GRP is highly stable and virtually immune to the affects of salt and most common petrochemicals and airborne pollutants. GRP has a similar strength to stainless steel but is about 75 percent lighter, which helps lower transport costs and simplifies many installations. Intertec's Type 4X enclosures also include uniquely efficient insulation thanks to a proprietary triple-layer composite construction that 'sandwiches' advanced insulation material between sheets of GRP.

Compared to metal enclosures and cabinets, which users sometimes need to insulate themselves using ad-hoc techniques, Intertec's enclosures come with embedded insulation providing near-perfect thermal performance - avoiding 'thermal short cuts' between interior and exterior that can lead to cold-spots and problems from condensation. This aspect makes Type 4X GRP enclosures and cabinets ideal for applications in the harshest of environments such as the Arctic, Alaska, and any other region or application environment that must deal with difficult conditions involving ultra-cold or -hot temperatures.

Intertec has offered a selection of Type 4X enclosures for many years for smaller-scale panel/wall-mounting or freestanding (pipestand-mounting) outdoor equipment protection applications. The company has now added more enclosures and larger rectangular cabinets to the offering. The new range can be broken down into two main categories.

The first is two-part enclosures. One Type 4X style offers two part enclosures with a diagonal opening - for simple and ergonomic access to housed equipment. There are five standard choices offering volumes from 87 to 277 litres. A second style in this category is rectangular two-part panel-mounting enclosures with one part acting as a door and the other housing the installed equipment. There are 11 choices of this style offering volumes from 20 to 250 litres. In addition to these standard products, Intertec can now provide Type 4X enclosures in custom shapes and sizes, up to maximum volumes of 980 liters for diagonal opening styles, and 500 litres for rectangular box styles.

The second category is rectangular floor- or wall-mounting cabinets, with single doors. These can now be provided in Type 4X variants in a wide range of standard sizes up to maximum heights of 214 cm, widths to 110 cm, and depths to 110 cm - a maximum volume of 2590 litres. Further specification choices include two styles of construction for applications involving lighter or heavier equipment loads.

The independent testing to NEMA's Type 4X specification was performed by the Canadian Standards Association (CSA). To comply with the CSA 22.2 94.2-07, UL50/50E and NEMA 250 standards, Intertec's Type 4X enclosures must prevent the ingress of dust and be watertight against rain, sleet, snow, water splashes and hose-directed water. They must also be undamaged by the formation of ice on external surfaces, and provide additional protection against corrosion. The protection level is broadly equivalent to the international IP65 rating, but tests ingress protection using much more powerful water jets - at approximately 20 times the flow rate required by IP65 (and over twice that of the higher standard IP66). All of Intertec's new Type 4X enclosures are also certified to the IP65 standard.

#Intertec #PAuto @Wordsun_Ltd 

Fire-resistant shelters for chemical plant.

Novel outdoor equipment shelters from Intertec Instrumentation have been chosen to help a leading European chemical manufacturer to upgrade its distributed plant control system.

Constructed using unique composite GRP (glass fibre reinforced polyester) materials, four Intertec shelters will provide advanced fire resistance properties. This attribute will simplify the housing and protection of electronic control and instrumentation equipment at optimised satellite locations within the processing plant.

Additionally, the GRP-based fabrication materials significantly reduces the weight of the shelters compared with traditional metal- or concrete-based constructions. In this application, this weight reduction will allow the plant operator to further optimise the positioning of the control system by mounting three of the shelters at height on steelwork frames.

The shelters offer F60-rated passive fire resistance, providing a barrier to fire spread for 60 minutes. This is achieved by means of a unique composite material that combines GRP sheets with embedded layers of mineral wool.

The shelters provide large interior floor areas up to 55 m2 (5 x 11 m). To help speed this plant upgrade project, Intertec is providing the plant buildings fitted with lighting, a raised floor to accommodate cabling, and ducting for the cooling air with a sophisticated downflow cooling system to protect the electronics equipment.

#Intertec #PAuto @Wordsun_Ltd

Advanced outdoor shelters .

A novel new style of outdoor shelter for process plant applications is being introduced by Intertec. Featuring a cooling system based on a hybrid combination of unpowered passive and active powered technologies, the shelter helps to ensure stable and highly reliable operating environments for control, analyzer and instrumentation electronics. The new shelters can greatly simplify the operation of field equipment in hazardous and remote areas.

A model with LED lighting effects

Passive cooling of field equipment enclosures is an influential weapon in the battle to protect electronics installed in hot and harsh environments. When configuring passive cooling systems there is a need for a fairly large difference between night and day temperatures. This means that passive cooling is usually suited for applications in arid climates. However, by making the passive cooling system hybrid, with the addition of one or more active powered cooling elements, it's possible to create semi-passive shelters that can be used in many different climates - even equatorial regions. If an active cooling element should fail for any reason - because of an electrical power loss for example - the passive cooling system retains enough capacity to keep the shelter cool for days, giving maintenance staff plenty of time to visit.

Passively cooled shelters work by exploiting the temperature swing over the climate's daily cycle. A buffer tank of water or other fluid provides the medium to store the coolness of the night and moderate internal temperatures during the day, via heat exchangers. Hybrid cooling can be achieved by additions such as solar-powered micro pumps to boost water circulation, or if mains electricity is available, by using a water chiller or air conditioner. Passively cooled shelters can also be made significantly smaller and lower cost by making them hybrid.

A model with LED lighting effects (see pic) that illustrate the natural circulation principle of passive cooling systems will be featured at this years Achema in June*. This demonstration model will also illustrate a radical new form of shelter configuration that can dramatically reduce plant building sizes, and greatly simplify construction and installation. Known as the PERI SHELTER, it makes all the system components that are required for normal operation accessible via the building's exterior. Panel-mounting enclosures on the exterior provide access to electrical connection and I/O termination points, and cooling systems. Touchscreen HMI panels can also be fitted to external walls, allowing operators on the ground to monitor a control element such as a PLC or make adjustments to control programs locally via an inspection door.

Among many design problems and costs that can be avoided by the PERI SHELTER's 'inside out' approach to layout are the need to make plant buildings blast proof and fire resistant because personnel might be inside, major reductions in size by eliminating desks, control panels, door opening spaces, aisles/walkways/escape routes etc, and much simpler internal atmospheric control requirements.

Intertec's PERI SHELTER concept meets a growing problem faced on process automation projects. Automation systems are becoming more complex, due in large part to ever more sophisticated safety technology. Adding such equipment into already crowded plant areas - often close to the process in hazardous areas - has become a major challenge and a major contributor to project cost overruns.

"PERI SHELTERS can cut project costs by millions of dollars, and cut months off of project timescales" says Intertec's Silvia Ludewig. "For turnaround projects in existing plants, the unmanned shelters can provide an alternative to installing larger and expensive manned buildings such as satellite instrument houses or remote instrument enclosures. They fit easily in crowded spaces, close to the process in hazardous areas. And, with the benefit of Intertec's unique hybrid cooling technology, they are also ideal for SCADA applications and other remote location applications."

A key contributor to the advanced environmental protection performance of Intertec shelters is construction from GRP (glass reinforced polyester) materials. The GRP panels employ a composite 'sandwich' construction to incorporate a very high degree of insulation, plus surface protection that can survive extreme challenges - including very high levels of UV and dust and sand abrasion. GRP is an inherently inert material that is virtually immune to corrosion and atmospheric pollutants. It is also resistant to a broad range of chemical media. The insulation in Intertec's shelters substantially reduces the total cooling power required compared with shelters fabricated using insulated steel or aluminium, and provides highly stable operating environments for sensitive equipment such as analyzers. Intertec's composite GRP panels use insulation layers bonded between GRP sheets. This style of fabrication eliminates 'thermal short cuts' between shelter interior and exterior that can result from the fixings often used with traditional insulated metal constructions.

*Intertec at ACHEMA, Frankfurt 11-15 June 2018, Hall 11.1, booth F61

#Intertec #ACHEMA18 #PAuto #Pharma

GRP inspection door for outdoor installations.

A unique inspection door for outdoor equipment protection enclosures has been announced by Intertec. The new GRP Inspection Door comes with a window frame made entirely from GRP (glass reinforced polyester) - a material offering a very high degree of protection against corrosion combined with excellent thermal insulation.

The design offers a more durable alternative to the conventional aluminium or stainless steel window frames commonly used for field equipment in harsh environments, helping to extend the lifecycles of business-critical process control and instrumentation equipment. Doors are available with either IP54 or IP65 ingress protection ratings.

Intertec's GRP inspection doors are ideal for enclosures and cabinets containing control and instrumentation equipment fitted with user interfaces, indicators and displays. This embraces a broad range of commonly-used field equipment including process transmitters and PLCs. A lot of this type of equipment is increasingly being located deeper inside the processing areas of a plant, where environments can expose the equipment to harsh and corrosive atmospheres.

GRP is an inherently inert material that is virtually immune to corrosion and atmospheric pollutants. It does not rust or degrade in any meaningful way, and is resistant to a wide range of chemicals. The GRP sheet material used in the door's construction also provides excellent thermal insulation for field equipment requiring heating or cooling. GRP's thermal conductivity is around 5,000 times less than aluminium and 1,000 times less than steel - alternative materials widely used for window frames in this application. This helps to eliminate 'thermal short cuts' between interior and exterior, which can lead to cold spots and condensation problems. In its basic form, these properties make GRP a superb material for robust outdoor enclosures - allowing maintenance-free lifecycles of 30 years and more.

Two variants of the new GRP inspection door are available with window frames measuring approximately 50x35 or 67x47 cm (19.7x13.8 or 26.4x18.5 inches). Intertec can fit these frames with acrylic, safety glass or insulated glass panels to suit the application. Options include an insulated glass panel filled with Argon - which has a significantly lower thermal conductivity than air. The U-value of the Argon-filled panel is 1.7 W/m²K. The inner glass pane of this unit also features a heat-reflecting coating offering a g-value of 50% to reduce the impact of solar energy heat transmittance (untreated insulating glass has a g-value of around 90%).

Intertec's GRP Inspection Door can be fitted with a variety of handles and locks to suit the application. As standard it comes in light grey, but it is optionally available in other colours. An antistatic version of the door is also available for hazardous area applications.

#Intertec #PAuto 

Protecting vital control systems!

Outdoor shelters with a novel combination of Intertec's passive and active cooling technologies have been chosen to protect vital control systems at a Middle Eastern refinery. The environmental protection solution is being provided as part of an upgrade to the burner management systems at the core of the plant's refining processes.

High-reliability PLC-based systems will provide the control and safety functions needed for management of eight separate burners. However, the physical location of the systems - deep inside the process - and the harsh coastal desert location of the refinery, pose major additional challenges for this engineering upgrade.

The project partners selected the field instrumentation protection specialist Intertec to provide the enclosure solution because of its experience of harsh environments, and for its novel protection ideas that will enhance the overall functional reliability of the control systems.

Intertec's design response to the engineering problem incorporates two major features. The first is custom-designed remote instrument enclosures (RIEs) based on composite GRP materials. The materials protect against the many environmental challenges of the application including very high levels of UV, extremes of temperature, dust and sand abrasion. The second key part of the protection solution is a regulated internal environment that provides the essential cooling required for the reliable operation of the electronics in the harsh Middle Eastern climate. This is maintained by a combination of three cooling methods, in order to provide exceptional redundancy against failure. The IP65-rated shelter also utilises the plant's instrument air service - after drying and filtering. This provides a slight positive pressurisation of shelter interior atmosphere for safe operation in a hazardous area, as well as ensuring there are no corrosive chemicals in the atmosphere.

"Intertec's novel approach to this field protection problem meets a growing need in today's process world," says Keith Wood, Intertec's project manager. "Control and instrumentation systems are being sited much closer to the process, deep inside corrosive and hazardous areas - and this in turn is demanding higher levels of reliability. GRP enclosure construction materials, combined with innovation in the associated protection systems such as cooling, are helping engineering consultancies to create advanced new plant solutions."

Three cooling technologies will protect the PLC-based control and safety systems: an air cooler, a water cooler, and a water-based passive cooling system. In normal operation, the water cooler and passive cooler operate in combination to decrease the internal operating temperature of the eight shelters. The aluminum heatsinks of the PLCs and cases will be installed directly onto conductive mounting plates, in contact with the liquid-based cooling media. This conductive heat transfer provides a much more efficient cooling mechanism in addition to conventional air convection.

The passive cooling system works by exploiting the regional climate's large temperature swing over the daily cycle, using water as a medium to store the coolness of the night and moderate internal temperatures during the day. Natural convection moves the water around the system and its heat exchangers. In this application however, Intertec's addition of an electrically powered water cooler improves efficiency - and reduces the size of the water tank needed for the passive cooling circuit. If the powered water cooler should fail, the electrically powered air cooler switches on to maintain the internal environment. If both of the powered water and air coolers fail, the passive system has enough cooling and storage capability to maintain a low shelter temperature for many days - giving refinery staff plenty of time to effect repairs.

One of the advantages of this multi-faceted approach to cooling is a reduction in size of the protection solution. A pure passive system would need to be sized to deal with the hottest days of the year, which would necessitate a large water tank for a Middle Eastern location. The inclusion of two other cooling technologies allows each cooling component to be reduced in scale - and cost - as the systems can work in combination to handle occasional extremes of duty cycle. In most normal operational cases, each cooling technology has the capacity to handle the load by itself. This particularly reduces the cost of the air cooler element, as the system must be ATEX-rated - adding significant costs.

Another interesting feature of Intertec's solution is the size of the shelters. The shelters are scaled to accommodate the PLC control and safety systems, but are also designed to be accessed only from the outside in normal plant operation. The powered water and air cooler units are mounted on an external wall. Several other small panel-mounting enclosures provide external access to the electrical connection and I/O termination points. The PLC is fitted with a touchscreen HMI panel that sits on an external wall - allowing operators on the ground to make adjustments to the control programs locally if needed. A door is incorporated in the shelter design but this is locked in normal operation, and only accessible under controlled circumstances. This reduces the size and cost of the enclosures, and eliminates the need to make them blast proof. All eight shelters use a common design with a footprint of around 2 x 3 metres, plus a heat exchanger on the roof, which also overhangs to provide shade.

The need for a custom shelter shape was easily handled by Intertec's extensive investment in manufacturing automation, which includes large-bed CNC cutting, routing and drilling machinery that can make custom panels in quantities as small as one.

The shelters will be assembled and factory tested at Intertec's European manufacturing centre in southern Germany. This plant incorporates a modern and well equipped assembly and testing line. Intertec will install the PLC and safety control system modules inside the shelter, to the design layout provided by the project engineers. The shelter will then undergo two separate in-depth testing programs. One will test all the features of the shelter including pressurisation and the correct operation of the cooling systems - which will involve the use of a very large and sophisticated environmental test chamber. The functioning of the PLC-based control and safety system will also be tested in conjunction with the project engineers, before the finished shelters will be transported in standard shipping containers to the refinery, ready for connection to the process. Delivery of the eight RIEs will start in the second quarter of 2017.

#INTERTEC #PAuto #Oil

Explosion proof cabinets for field instrumentation in process plants.

Intertec has launched a new range of explosion proof cabinets to protect field instrumentation operating in hazardous areas.

Ex p explosion proof cabinets 

According to Klaus Dieter Meyer of Intertec, “There is a growing need for Ex p field protection cabinets and enclosures in the process sector. Analyzers are getting smaller and plant operators are keen to site these as close to the process as possible, in order to shorten sample lines and thereby improve the accuracy and speed of results processing. Our ability to create Ex p cabinets and enclosures of virtually any design and complexity provides system integrators with a very flexible and cost-effective solution.”

Available in a diverse range of standard sizes, as well as in custom shapes up to walk-in shelter size, the cabinets are certified for use in Zone 1 and Zone 2 hazardous areas. They are ideal for housing forward-placed analyzer equipment in industrial process facilities such as petrochemical/oil refineries and fertilizer production/storage plants, and also provide the possibility to install non-Ex rated analyzers and instrumentation inside Zone 1 or 2 classified environments.

Intertec’s pressurised explosion proof (Ex p) cabinets are constructed from GRP (glass reinforced polyester) composite materials. These materials are highly resistant to corrosion and have a similar strength to stainless steel, but are about 75 percent lighter, making them ideal for equipment containment and personnel shelter applications. They are especially suitable when robustness and rigidity need to be combined with low mass – such as on offshore platforms. They are also ideal for areas where there is a need to mitigate injury to personnel or damage to equipment, such as on sites where there is risk of an explosion.

GRP composite materials also have a much higher thermal resistance than metal. This simplifies the construction of cabinets that provide excellent insulation, greatly reducing the energy required to heat or cool the equipment. It also makes it easier to build cabinets without any thermally conductive links between their exterior and interior surfaces, thereby avoiding creating cold-spots which can lead to problems with condensation.

Intertec is capable of producing single-piece panels of GRP composite as large as 6 x 12 metres. This enables the company to create cabinets of virtually any size. The panels can be chemically bonded to create very tight sealing that prevents the ingress of hazardous gas and reduces the consumption of air, which is used to create the slight positive over-pressure needed for Ex p protection. Any requirement for special air locks to allow unfettered access to equipment inside the cabinet or shelter can be accommodated very easily.

The pressurised cabinets are equipped with a control unit that regulates the flow of inert purging gas or compressed air, and then monitors the pressure inside the cabinet to ensure that it is maintained slightly above atmospheric pressure by automatically compensating for any leakage losses. Intertec works with a number of controls manufacturers to equip its Ex p cabinets with the most appropriate type of purging and pressurisation systems.

Each partially equipped enclosure is then tested by Intertec at one of its manufacturing plants, before being delivered to the system integrator for installation of the analyzer instrumentation. Final safety testing of the complete unit is carried out at the integrator’s facility, prior to its installation at the customer’s site. Intertec is certified by various competent bodies – including PTB (Physikalisch-Technische Bundesanstalt) – to perform the necessary compliance testing.

 #Intertec #PAuto #Ex

Enclosures comply with CSA, UL and NEMA standards.

An extended range of Type 4X outdoor equipment enclosures that comply with CSA, UL and NEMA standards is now available from Intertec. Manufactured from proprietary GRP (glass reinforced polyester), the enclosures combine high performance environmental protection capabilities with exemplary long-term resistance to corrosion. They are ideal for protecting instrumentation and electrical equipment sited in marine and coastal areas, where the presence of salt in the atmosphere can severely damage traditional steel cabinets and shorten their service life significantly.

An additional advantage of Intertec’s Type 4X enclosures is that they provide superior protection when used in a Class I, Division 2 or Class I, Zone 2 hazardous area to protect equipment that does not constitute a source of ignition. Typical applications include housing non-arcing connections and connection devices such as joints, splices, terminals, terminal blocks and junction boxes.

Following qualification testing by the Canadian Standards Association (CSA), a large and growing number of Intertec’s MULTIBOX and DIABOX enclosures are now available in Type 4X versions that comply with the relevant parts of the CAN/CSA C22.2 No 94.2-07, UL 50/50E and US NEMA 250 standards for electrical equipment enclosures. All three of these standards stipulate that the enclosures must provide enhanced protection against corrosion, as well as other environmental effects.

Intertec’s MULTIBOX and DIABOX families are popular choices for housing process monitoring and control equipment in the field. Offering a wide range of containment capacities from 25 to 277 litres, they are designed for convenient mounting on walls/panels or small-footprint pipe stands.

To comply with the CSA 22.2 94.2-07, UL50/50E and NEMA 250 standards, Type 4X enclosures must prevent the ingress of dust and be watertight against rain, sleet, snow, water splashes and hose-directed water. They must also be undamaged by the formation of ice on their external surfaces. This level of protection is broadly equivalent to the IP 66 rating of the international IEC/ANSI/EN 60529 standard.

The hose-down test stipulates that all gasket seams be subjected to a high pressure water spray. This involves subjecting the enclosure to a steady stream of water at a distance of 3 metres from a 1 inch nozzle at a flow rate of 246 litres/minute. MULTIBOX and DIABOX enclosures feature a moulded two-part construction, which means that they only have a single joint between their two halves, making it much easier to ensure a reliable seal. The mating surfaces are sealed by a continuous and highly durable silicon or EPDM synthetic rubber gasket embedded within a containing groove – this same design provides ingress protection ratings as high as IP68.

Intertec goes to considerable lengths to ensure that the Type 4X versions of MULTIBOX and DIABOX enclosures maintain their IP ratings under extreme or fast-changing weather conditions. For example, if a hot enclosure is subjected to a stream of cold water, as might be the case during a sudden thunderstorm in a hot climate, the air inside will cool down and contract. In a conventional unvented enclosure, this can create a partial vacuum that causes air – and water – to be sucked past the joint seals. To prevent this problem, Intertec’s Type 4X enclosures are equipped with a special waterproof ‘breather’ seal that equalizes the air pressure and ensures that full sealing integrity is maintained under all operating conditions.

Type 4X enclosures must also provide enhanced protection against corrosive agents. Metallic enclosures which are susceptible to corrosion are required to undergo a series of stringent material tests. The NEMA 250 standard, for example, calls for two salt spray tests, one with a duration of 200 hours, together with a test that involves subjecting sample material to a moist mixture of carbon dioxide, sulphur dioxide and air for 1,200 hours. The GRP material that Intertec uses for all its enclosures is inherently resistant to corrosion from these types of atmospheric pollutants and therefore does not require qualification testing in its own right.

Intertec’s GRP is a relatively inert material that has enormous advantages over the sheet metal materials commonly used for enclosure construction. It is highly stable and virtually immune to the affects of salt and most common petrochemicals and airborne pollutants. An excellent thermal insulator, GRP has a similar strength to stainless steel but is about 75 percent lighter, which helps to lower transport costs and simplifies installation.

Intertec’s DIABOX enclosures are available with a wide choice of containment capacities from 27 to 277 litres. They feature a two-part design with hinges on their top edge and open diagonally to provide a very ergonomic and self-contained field protection solution. The lower half of the enclosure houses the instrumentation – process and electrical connections are usually made via the rear or base of the unit – while the upper half functions as a fully retained lid.

MULTIBOX enclosures offer a similarly extensive choice of sizes, with 12 standard models covering containment capacities from 25 to 250 litres. Featuring a two-part construction, they can be mounted vertically or horizontally, with the instrumentation contained in either the deep or shallow section. Process and electrical connections are usually made via the top or bottom of the unit.

For applications that require protection against extremely cold climates, all MULTIBOX and DIABOX enclosures are available in ‘arctic’ versions that are suitable for use in temperatures as low as minus 60 degrees Celsius. Depending on the model, the additional thermal insulation is either provided by an internal polypropylene liner with a polyurethane (PU) foam infill, or the entire enclosure is manufactured from Intertec’s proprietary triple-layer composite-GRP material, comprising inner and outer walls of GRP with a PU foam core.

Many of the standards compliance tests on Type 4X enclosures – such as ingress protection, impact resistance and gasket ageing – are similar to those used on the type of increased safety (Ex e) enclosures designed for use in hazardous areas. As Intertec’s CEO, Martin Hess, points out, “Broadly speaking, it is this similarity which allows installers to use our Type 4X enclosures to house non-hazardous equipment in hazardous areas, without having to resort to using large and labour-intensive sealed conduits. We also believe that our Type 4X enclosures will make it much easier for installers to adapt ATEX compliant products on the European market to comply with hazardous area safety standards in North America.”

Explosion-proof HVAC system for process control system cabinets.

Intertec has developed an innovative ATEX-compliant HVAC system that provides a complete all-in-one climate control and personnel safety solution for walk-in style process analytical instrumentation shelters. It is customisable and scaleable to suit a broad range of applications, and can be supplied fully integrated within the shelter or as an external standalone unit.

Designed specifically for hazardous area applications up to zone 1, the system delivers a steady flow of conditioned and filtered clean air to the shelter, maintaining it slightly above atmospheric pressure to prevent the ingress of dust or gas. It is especially suitable for oil/gas refineries, petrochemical and chemical plants that operate in extremely hot or cold climates, or where atmospheric contaminants pose safety, health or corrosion issues with conventional through-flow air conditioning systems.

To help ensure measurement accuracy, sensitive equipment such as process analyzers and sample conditioning systems needs to be maintained at a constant temperature. This is usually achieved by using a thermally regulated shelter. And to avoid long sample transport tubes, which can affect accuracy and delay response times, the equipment is often located as close to the process as possible. These factors can necessarily involve housing operating personnel and equipment in a potentially hazardous area of the plant, demanding that adequate safety precautions are taken. The prime requirement is that the shelter and any associated equipment such as air conditioners must to be explosion-proof.

Nearly all explosion-proof air conditioning systems on the market are contained in metal enclosures, which are susceptible to corrosion. Intertec’s new HVAC system is unique in that its entire housing is constructed from the company’s proprietary GRP (glass reinforced polyester) triple-layer composite material. This comprises inner and outer layers of GRP enclosing a thermally insulating core; the wall thickness and core properties can be varied to suit the application and operating environment. The GRP is the same electrically conductive variant that Intertec uses for its explosion-proof analyzer shelters. It fully complies with the antistatic requirements of the DIN/EN/IEC 60079-0 safety standards for equipment intended for use in explosive atmospheres.

As a construction material for equipment shelters, composite GRP has enormous advantages over metal – it is impervious to corrosion from most commonly-encountered atmospheric contaminants and is an excellent thermal insulator. It has a similar strength to stainless steel, but is about 75 percent lighter, making transport, site preparation and installation easier and less expensive.

A further key feature of Intertec’s new HVAC system is that it can be fully integrated within the analyzer shelter, or installed as a standalone unit against its external wall. The option of internal installation has major advantages: it saves space and cost, reduces energy consumption by eliminating the thermally inefficient air duct of conventional standalone units, and facilitates configurations that are simply not possible with external systems. The system is also fully scaleable to suit the application requirements and intended operating environment, with heating and cooling capacities from 6 kW upwards.

The first systems that Intertec is building are designed primarily for ventilation and cooling purposes, to maintain analyzer shelters located in a relatively warm climate at a constant temperature 24/7, by compensating for differences between daytime and night-time temperatures, and for seasonal variations throughout the year. Occupying just 4.4 cubic metres of space, they provide an 8 kW cooling capacity and a 5 kW heating capacity, and accommodate an ambient (external) temperature range of minus 20 to 55 degrees Celsius.

A variety of fully integrated heating options is available, including an explosion-proof electrical heater and a temperature-controlled condensate vapour heat exchanger. Dehumidification is accomplished by refrigeration; the moist incoming air is initially cooled to promote condensation, and then heated – if necessary – to bring it back up to the required temperature.

All non-explosion-proof switches and control devices in the HVAC system are contained within flameproof (Ex d) protective housings, and all electrical junction boxes are enhanced safety (Ex e) types. Every internal electrical circuit carries an IP65 protection rating. The explosion-proof refrigeration unit comprises a powerful hermetically-sealed compressor, an air cooled condenser with an axial fan, and a refrigerant collector. The refrigerant is CFC-free non-flammable R134a. The system has a low acoustic noise level and is fitted with an automatic maintenance-free condensate drain as standard.

The air supply for the HVAC system can be derived locally – the input port is fitted with a high efficiency particulate filter. Alternatively, if the shelter is sited in a hazardous area, the air can be ducted in from a fan and filter unit located outside the immediate area, via a stack. Spent air, together with transported heat from the shelter and waste heat from the compressor unit, is exhausted direct to atmosphere.

The HVAC system operates entirely automatically. The flow rate of ventilating air depends on the application. The standards for explosion protection of pressurised process analyzer shelters, such as IEC/EN 61285 and NFPA 496, mandate various air exchange rates to ensure adequate dilution of explosive or poisonous gas leaking from equipment inside the shelter, ranging from 5 to 12 complete air exchanges per hour. The system’s main axial fan is monitored by a differential pressure switch, to ensure that the air inside the shelter is constantly maintained at a slightly higher pressure than atmospheric, automatically compensating for any sudden increase in air leakage when the entry door is opened. Any over-pressure conditions are adjusted by a poppet valve. The air temperature inside the shelter is controlled by a capillary tube room thermostat with its remote sensing bulb located in the system’s air output duct for accuracy.

Intertec’s new explosion-proof HVAC system is ATEX certified for gas group IIC and temperature class T3 or T4 applications. The system is designed to operate directly from a standard 400 V 50 Hz or 460 V 60 Hz three-phase supply.

Containing wireless in process applications!

An increased customer demand for equipment housings to contain wireless process monitoring equipment in outdoor environments has been remarked on by Intertec. The company attributes this partly to increased use of industrial wireless sensor network (WSN) technology, but mainly to the growing industry awareness that the glass-reinforced polymer (GRP) composite material it uses for all its protective enclosures is electromagnetically transparent.

Electromagnetically transparent GRP
 enclosures are ideal for field
protection of wireless process
 monitoring instruments such as
pressure, flow and level transmitters.

Until recently, process industry take-up of WSN technology has been relatively slow, possibly because competing wireless standards have made systems designers wary of making the wrong choice. However for mainstream industrial process applications, the field has now narrowed to just two standards – WirelessHART and ISA100.11a. Both standards define secure, self-healing wireless mesh technology operating in the 2.4 GHz ISM band, using IEEE 802.15.4 standard radios. ISA100.11a systems use Internet protocols and are designed for multiple wireless communications purposes, while the simpler WirelessHART systems are primarily intended only for use with process instruments; they are also backward compatible with wired HART devices, which are used extensively within the process sector for remote data acquisition.

Intertec has long been aware that one of the many benefits of its GRP composite material is electromagnetic transparency – it produces a wide range of frangible environmental protection cabinets and shelters for radar and instrument landing systems at airports which are designed not to reflect or interfere with radio signals. The housings are also used extensively for cellular and satellite communications applications, as well as satellite navigation systems; the GRP material causes no measurable loss of received or transmitted RF signals, so the equipment antennas can be contained within the enclosure. However until now, Intertec has not actively promoted the fact that the non-metallic construction of its products is also ideally suited to field-based 2.4 GHz wireless sensor networks, especially for applications where external antennas are inadvisable because of their susceptibility to accidental damage.

According to Intertec’s CEO, Martin Hess, “More and more process industries are starting to deploy wireless field instrumentation, although at this stage it’s only for monitoring and diagnostics – I think that it will still be a long time before wireless is used for process control purposes. Having said that, the technology offers huge benefits for companies with large remote data acquisition needs, completely eliminating the cost and inconvenience of cables. We believe that our GRP composite enclosures provide plant engineers with a future-proof path for WSN technology – even if they choose to install cabled instruments today, by selecting the right type of enclosure at the outset they will make it easy to deploy wireless instrumentation whenever they wish, without having to change the entire installation.”

A number of Intertec’s customers, as well as manufacturers of wireless process monitoring automation, have started to evaluate the electromagnetic performance of its GRP-based enclosures for housing field-based WSN equipment. Initial results are very promising: third-party tests involving a WirelessHART gateway and a WirelessHART field device, both with built-in antennas and sited in different rooms, found that when the field device was placed inside a standard Intertec instrumentation enclosure it continued to function properly, with no measurable loss of signal.

The tests were conducted using a model from Intertec’s Multibox range, but the same results are likely to be obtained from many of the company’s enclosures that use a similar form of construction, including its popular Diabox range. Both types of enclosure are moulded from hot-pressed GRP. They are optionally available in ATEX-compliant antistatic versions for use in hazardous environments and can also be fitted with an internal layer of polyurethane foam for additional thermal insulation – all of the materials are electromagnetically transparent and have no effect on signal reception or transmission.

Many of the leading wireless process monitoring instruments on the market, including a number of pressure, flow and level transmitters, offer the option of local (on-instrument) or remote antennas. However, if the instrument needs to be housed in some form of enclosure to protect it against a harsh environment, this choice will not be available if – as is commonly the case – the enclosure is made from a metal such as steel or aluminium; its RF shielding effect will necessitate use of a remote externally mounted antenna to secure adequate signal strength. Aside from incurring additional implementation costs, use of an external antenna also involves drilling an extra hole in the enclosure – probably in its top, which is potentially the worst place for leaks – and leaves a delicate structure open to physical impact.

Intertec manufactures all its protective enclosures for field instrumentation from proprietary GRP, either in the form of a single layer or a multi-layer composite containing one or more cores of special insulating and/or fire resistant materials. As well as being electromagnetically transparent and an excellent electrical insulator, the material has multiple advantages for plant designers seeking to protect field instrumentation against environmental effects, especially for long lifecycle applications and where harsh media or severe local climatic conditions might be encountered. GRP is inherently inert and immune to damage from most common chemicals and petrochemicals. It has a similar strength to steel, but weighs about four times less, and will not corrode in the presence of salt – which is why it is increasingly becoming the enclosure material of choice for offshore and coastal oil and gas applications. GRP also has low flammability and is self-extinguishing, as well as having a very low thermal conductivity that makes it easier to implement efficient, condensation-free enclosures.

Protecting small installations.

A new range of small GRP cabinets from Intertec provides installers with increased flexibility for protecting outdoor equipment. The new MINICAB housings combine a relatively high containment capacity with convenient pipe stand or wall mounting, and feature a flat full-size hinged door for quick and easy access. They are designed to help customers simplify the layout, installation and maintenance of outdoor equipment without having to recourse to large footprint free-standing cabinets.

Ideal for protecting small installations
of electrical, analytical or safety
equipment against unauthorized
access and the effects of weather.

MINICABs are especially suitable for protecting smaller-scale field-based installations such as electrical, analytical or safety equipment against the effects of weather and unauthorised access. Their GRP construction also makes them ideal for long-life applications in harsh climates, and in plants handling chemicals and petrochemicals.

The company is initially launching the MINICAB 44 model, which has a capacity of approximately 44 litres and measures just 506 x 356 x 245 mm (HxWxD); larger versions will follow. This is the smallest cabinet-style housing that Intertec has produced to date – other products in this size range comprise two-part enclosures that split open for access.

These cabinets are manufactured from hot-pressed GRP (glass reinforced polyester) for robust, maintenance-free performance in harsh outdoor environments. This material does not corrode and is impervious to the effects of salt and common atmospheric pollutants, making it suitable for use in any type of rural, urban or industrial environment. An unobtrusive light grey in colour, the GRP is also UV resistant, has very low flammability and is self-extinguishing. An optional exterior gel-coat offers added protection for applications that involve prolonged exposure to intense sunlight.

All hinges and mounting fixtures are manufactured from corrosion-resistant 316 stainless steel and the door can be fitted with a lockable handle or security-key mechanism. As standard the cabinet carries an IP54 rating, but IP65 versions are available to order for applications that require higher protection against water ingression. A durable EPDM rubber compression seal is incorporated in the moulded retaining groove that runs the full length of the joint between the cabinet and the door. The cabinet is also impact resistant.

To help simplify installation and ensure optimum thermal performance, equipment can be attached to a separate mounting plate, which is then secured inside the cabinet. Intertec offers a choice of corrosion resistant GRP or stainless steel mounting plates. For applications where it is necessary for personnel to be able to see annunciator devices such as equipment status indicators or meters without having to open the cabinet, the door can be fitted with an acrylic or safety glass window.

Intertec MINICABs are also available in versions that are suitable for use in potentially explosive atmospheres. Options include IEC 60079-0 compliant models that use a special electrically conductive form of GRP to prevent the build-up of electrostatic charge.

Sunshade for process instrumentation!

Intertec has launched a large cube-shaped sunshade for process instrumentation. It provides plant engineers with a highly cost-effective means of shielding equipment such as electronic monitoring systems, explosion-proof junction boxes or analyser installations from solar radiation. Dubbed CubeShade, the protective cover measures 600 x 550 x 500 mm (HxWxD). This provides a massive 165 litre capacity shaded environment that make it easy to accommodate and protect large or multiple instruments, as well as simplifying maintenance access.

The new sunshade design is manufactured using an automated moulding process and offers a particularly economic solution for this common application. Most process instrument sunshades on the market are relatively small and are often targeted at single instruments or small-scale field equipment installations. If Intertec needs to provide solar protection for larger installations – such as two or three process transmitters – sunshades are usually created to suit the specific application by building up multiple layers of glass reinforced polyester (GRP) in a custom mould to achieve the necessary thickness. This manually-intensive process can increase costs significantly. And if the number of sunshades required runs into hundreds – which is common for greenfield projects – the extra costs can be high. 

Intertec's new CubeShade is constructed entirely from glass fibre reinforced sheet moulding compound (SMC). This combines chopped glass fibres, fillers, polyester resin and a catalyst in the form of a ready-to-mould composite that is ideal for low cost, high volume manufacturing. The material has similar advantages to GRP for this type of application, including a high resistance to UV and corrosion from salt and common petrochemicals, and a low thermal conductivity, which helps to prevent heat generated by solar radiation being transferred to the shaded area. It also combines excellent rigidity and mechanical strength – for protection against impact – with a very low weight.

CubeShade’s single-part design and SMC-based construction facilitates production using automated moulding techniques. As standard, the body of the sunshade is 5 mm thick but incorporates 8 mm thick reinforcing ribs around the rim and down the back of the unit. These ribs also help to channel rain and melt-water run-off. 

Unlike many instrument sunshades on the market which essentially consist of a single top shade that only protects against overhead sun, Intertec’s design incorporates structural side walls that also shade low-angle sun, as well as providing partial protection against rain, snow, wind-chill, blown dust or sand and accidental impact. 

Intertec believes CubeShade is the largest SMC instrument sunshade on the market. The design is also suitable for use with equipment such as explosio-proof junction boxes or distribution units and is likely to prove especially popular for new-build processing plant projects. 

CubeShade can be mounted on a standard two-inch pipe stand, or attached directly to walls or steel structures. It is also available in an electrically-conductive antistatic version.

Alternative to cabinets for instrumentation!

A new high capacity, easy-access enclosure from Intertec provides plant engineers with a versatile alternative to free-standing cabinets for the environmental protection of field-based process instrumentation. Developed at the request of a Russian oil refinery, the enclosures are made from tough glass reinforced polyester (GRP) and include highly insulated options for use in extremely cold climates. They also offer more space than typical instrument enclosures, to allow plant personnel to use gloved hands when accessing the equipment. Typical applications include housing differential pressure flowmeters and process transmitters in refineries, petrochemical and chemical processing plants.

The new enclosures are the latest addition to their Diabox range of instrumentation protection solutions, which are moulded two-part enclosures that open diagonally to provide easy access for operating and maintenance staff.

The new Diabox 277 enclosure measures 600 x 750 x 600 mm (HxWxD) and has an internal volume of approximately 277 litres, depending on the level of insulation specified. Manufactured from a high-performance grade of GRP using a hot-press moulding process, the standard versions of the enclosure provide an exceptionally robust and rigid housing; they have a wall thickness of 6 mm yet typically only weigh 18 kg. This combination of rigidity and low weight means that the enclosures can be mounted on small-footprint pipe stands or clamped directly to process pipes, making them ideal for protecting instruments in locations where free-standing cabinets would be impractical due to the amount of ground space they require.

For applications that require protection against extremely cold conditions, Intertec produces an ‘arctic’ version of Diabox 277 that is suitable for use in temperatures as low as minus 60 degrees Celsius. This enclosure is manufactured from a proprietary composite ‘sandwich’ material, comprising inner and outer walls of GRP enclosing a closed-cell polyurethane (PU) foam core. The inner GRP wall provides a smooth, easy-to-clean finish. It also protects the foam against accidental physical damage, such as might be caused during equipment installation, routine maintenance or cleaning, thereby maintaining the enclosure’s thermal integrity and performance.

Despite its large size, the Diabox 277 has a very low heat transfer coefficient of 13 W/K, which minimises the power rating and operational cost of any freeze protection, anti-condensation, or temperature regulation heating that may be fitted. In the case of the ‘arctic’ version of the enclosure, its GRP-PU foam-GRP walls provide uniform and near-perfect insulation, resulting in an exceptionally low heat transfer coefficient of just 2.4 W/K.

All Intertec Diabox enclosures feature a two-part design with hinges on their top edge and a diagonal opening, to provide a highly ergonomic and self-contained field protection solution. The lower half of the enclosure houses the instrumentation – process and electrical connections are generally made via the rear and/or bottom surface – while the upper half functions as a fully retained lid.

The new enclosure features a continuous double seal, comprising a mechanical tongue and groove plus a flexible silicon insert strip, which is incorporated in the mating edges to ensure high integrity closure. As standard, Diabox 277 enclosures are rated to IP65 against the ingress of contaminants such as dust and moisture; for more severe applications involving prolonged exposure to driving snow or rain, IP66/67 versions are available. The 'arctic' version is also available with an IP68 rating.

Hundreds of accessories are available to configure the enclosure for specific applications. Among the options are viewing windows available in acrylic-, safety- or insulation-glass variants, and a special insulated adapter to prevent heat loss at the point where impulse lines and heat tracing cables enter the enclosure. The inner and outer layers of the composite material can be produced using an electrically conductive form of GRP to comply with the antistatic requirements of the international IEC EN 60079-0 standard for equipment used in hazardous environments where explosive gas or dust may be present. For applications that demand purging, Intertec offers a specially sealed Ex p version that is prepared for pressurisation in accordance with the IEC EN 60079-2 standard.

The GRP material that Intertec uses for its Diabox enclosures has multiple advantages for plant designers seeking to protect field instrumentation against environmental effects, especially for long lifecycle applications and where harsh media or severe local climatic conditions might be encountered. GRP is inherently inert and immune to damage from most common chemicals and petrochemicals. It has a similar strength to steel, but weighs some four times less, and will not corrode in the presence of salt – which is why it is increasingly becoming the enclosure material of choice for offshore and coastal oil and gas applications. GRP is also fire retardant and has very low thermal conductivity – making it easier to implement efficient, condensation-free enclosures.

The latest addition means that Intertec’s Diabox range of enclosures now includes six models, with capacities ranging from 27 up to 277 litres, enabling plant designers to choose the optimum size for their application – for single or multiple process instruments.

Passively-cooled cabinets protect instrumentation on world’s largest vessel!

High performance environmental protection cabinets for Shell’s ‘Prelude’ floating liquefied natural gas project are being supplied by Intertec. Designed specifically for extended service life in hazardous areas, the shelters incorporate innovative semi-passive cooling technology and are some of the most stringently specified instrumentation protection solutions that Intertec has ever produced.

Shell’s Prelude floating liquefied natural gas (FLNG) project is setting new engineering records. Designed to liquefy natural gas extracted from subsea wells by chilling it to -162 degrees Celsius, and to then store the liquid until it is offloaded to large LNG carriers, the vessel will be the largest in the world, with a length of 488 metres and a width of 74 metres. The hull of the vessel was constructed in South Korea and launched in December 2013. Due to enter service in 2017, the vessel will be towed to the Prelude and Concerto gas fields in the Browse Basin near Timor, about 200 km off the northwest coast of Australia, where it will be permanently anchored for about 25 years. After this time it will be inspected, overhauled and possibly moved to a new location, where it will be expected to provide a further 25 years of service.

Much of the on-line process analysis instrumentation on the Prelude FLNG vessel will be housed in purpose-built environmental protection cabinets supplied by Intertec. In total, the company is supplying 90 cabinets for sample conditioning systems and 30 cabinets for process analyzers, each designed to match the instrumentation content and layout precisely in order to optimise thermal performance.

As Intertec’s Commercial Director, Hans Geiger, points out, “Only three of the 120 cabinets that Intertec is supplying for this project are the same size. Our specialised design and automated manufacturing capabilities enable us to produce custom environmental protection products very easily, to optimise performance and match the space available on demanding applications like this.”

The cabinets are required to be capable of withstanding severe Category 5 tropical cyclones with wind speeds in excess of 252 km/h (157 mph) and to have a minimum service life of 25 years - with 50 years as a design aim. Additional requirements include a high degree of resistance to corrosion being caused by the saline environment and the presence of sour or acid gas, and the ability to cool electronics equipment without using explosion-proof air conditioning systems, which incur high capital and operating costs.

These environmental protection cabinets are constructed from a proprietary composite material comprising sandwich walls of long-fibre glass reinforced polyester (GRP) sheets, enclosing a core of polyurethane foam. The material has a similar strength to that of stainless steel but is about four times lighter, making it ideal for use on offshore platforms and floating structures, where every effort is made to minimise weight.

Other advantages include a very low thermal conductivity which facilitates the construction of efficient, condensation-free cooling cabinets, and an inherently high resistance to corrosion caused by salt or aggressive chemicals such as sulphur or chlorine. For this project, the external surfaces of the cabinets are further protected by a thick layer of UV-resistant gel coat. In order to meet the application’s high wind speed requirements, each cabinet is equipped with special built-in mountings – which are external to the thermally insulated parts of the enclosure – to secure the top and base to Prelude’s deck structure. All external metal components are fabricated from 316 stainless steel with a corrosion-resistant protective coating that is specified for ship use.

Each of the 120 Intertec cabinets incorporates a unique form of semi-passive cooling technology. The internal face of the cabinets' rear walls are fitted with a high efficiency heat exchanger, comprising one or more aluminium cooling plates and stainless steel coolant pipes connected to Prelude’s cold water supply system, which obtains ‘cold’ water from the deep sea by a 150 m long pipe below the vessel. Heat dissipated by the equipment in the cabinets is absorbed by the water and transferred to the vessel’s main water cooling system, where it is dissipated to the environment. The size of each cabinet depends on the power dissipation of the contained sample conditioning or process analyzer system, which ranges from 140 W to 900 W.

This form of distributed cooling has enormous technical and economic advantages, especially in hazardous areas or where space and weight is at a premium. It provides a very efficient means of removing heat from the cabinets without requiring local air conditioning systems, which would necessarily need to be explosion proof – and therefore expensive. Furthermore, transferring heat from individual air conditioners of below-deck cabinet installations to the ambient environment would be a major challenge and involve significant amounts of space-consuming air ducting. The semi-passive cooling system is inherently safe for use in a hazardous environment; at the cabinet level it requires little or no electrical power of its own and is virtually maintenance-free, making it ideal for long life-cycle applications.

The intended operating environment for Shell’s Prelude FLNG vessel poses significant instrumentation protection challenges. The Browse Basin is very close to the Equator, which means that it has a tropical climate with an average temperature of about 32 degrees Celsius. This moist and hot environment, combined with a salt-laden atmosphere, is highly conducive to rust formation, making non-metallic protection cabinets a sensible design choice. In some of Prelude’s more confined spaces, the ambient temperature could reach more than 50 degrees Celsius. Even under these extreme conditions, all of the passively-cooled cabinets that Intertec is producing for the project are designed to keep their internal air temperature below 35 degrees Celsius