Guidelines for choosing the ideal enclosure for any application.
Choosing the right enclosure to protect pump monitoring equipment is paramount. However, when the time comes to make a selection, many engineers and purchasing agents do not have a good grasp on the many enclosure options available. Enclosures are not typically noticed or thought about until a problem arises, and the instrumentation stored inside has been compromised.
The cost of inadequate protection can be tremendous. Not only can damaged equipment represent significant replacement costs, but the inability to monitor a pump for any length of time can be devastating to the pump and the process in which it is involved.
Whether this means that the monitoring of a pump at an oil field is interrupted or a pump leak is not detected during chemical processing because a sensor panel has been damaged, it is easy to see how monitoring disruption exacts real consequences if an enclosure is compromised.
Often, a pump operator may want to monitor a variety of conditions. These conditions include monitoring levels in fuel tanks or water towers; high- or low-pressure conditions that may lead to pump failure or system damage; high-current conditions or power loss; or high- or low-voltage conditions. Actual pump failure may lead to significant losses in production or possibly damage to the system or surrounding property in the instance of water or wastewater systems.
Pump applications in which remote monitoring has been implemented include almost any liquid medium such as oil, natural gas, petroleum, water, wastewater and varying chemicals.
Previous to wireless remote monitoring, the pump could only be inspected onsite by a technician. In the case of a pipeline or a remote well, days or weeks could pass before a problem is discovered. With remote monitoring, the well or pipeline can be monitored 24/7.
Often a problem can be detected before the pump has been damaged or fails, saving thousands in downtime, production and repair. For this reason, remote pump operators know that the monitoring system is as important as the pump system itself, and the enclosure is one of the most important components of the monitoring system.
Protection from a Distance
Pump monitoring and control enclosures are used in an endless range of industries including:
- Oil & gas
- Water treatment
- Petrochemical
When choosing the right protection for pump monitoring and control equipment, end users should be aware of the unique environmental and protection challenges that the enclosure must overcome. Perhaps more true in the oil and gas industry than in any other, remote monitoring applications need their highly sensitive communications equipment and antennae to withstand extreme environments in isolated locations. Remote monitoring enclosures must be ready for all extremes including:
- Desert plains
- Alaskan landscapes
- Heavy rain
- Saltwater environments
Choosing the right remote enclosure solution can often be reduced to a handful of factors that—when considered carefully—can guide the selection of the best equipment protection and eliminate the stress involved with the enclosure purchasing process. In addition, selecting the correct enclosure ensures longer life, for the box and for the equipment safely stored inside.
Since an enclosure will likely need to withstand and protect sensitive equipment for several years, research and consider which enclosure option will be most reliable.
Considering these important factors will help clarify the selection:
- Manufacturer
- Interference
- Security
- Mounting options
- Material strength and impact resistance
- Aesthetics
- Hinges
- NEMA rating
Manufacturer
An important way to ensure that the right enclosure is chosen for a pump monitoring application is to select an experienced manufacturer as a partner. A seasoned enclosure manufacturer will expertly assess the application and help select the best equipment protection. The key is to provide the manufacturer representative with as much information as possible.
- Where will the enclosure be mounted?
- What temperature range will it need to withstand?
- Will it be exposed to impact or water?
- What holes and/or modifications will the application require?
All these details will help an enclosure expert make an educated recommendation that will provide optimal protection.
Interference
Unique to the needs of remote monitoring applications, most pump monitoring instrumentation in the oil and gas industry is accompanied by an antenna to transmit data collected to the pump and system operators. One of the first considerations should be to determine whether the antenna—the vital centerpiece of a complex electronic system—will be stored inside or on top of the enclosure box. If the antenna must be protected from extreme weather and other conditions by storing it inside the enclosure, the type of enclosure material chosen will be paramount. A non-metallic box will be needed in this case, since the walls of metallic enclosures interfere with the antenna’s radio wave signal transmission.
Security
In tandem with antenna interference, security should be an important selection consideration. This is particularly true with pump monitoring applications, which are by nature remote and often not quickly accessible.
Attention from would-be vandals and thieves should be avoided at all costs. Storing an antenna on top of an enclosure can often signal that valuable equipment is stored inside. The more secure option is housing sensitive and expensive equipment—including the antenna—safely inside the enclosure.
Mounting Options
One of the most important questions to ask before selecting an enclosure is “How easy will it be to install panels in the enclosure exactly where I need them?” A well-designed enclosure will feature plenty of options for mounting back panels, face plates, circuit boards or any other component.
In addition, an enclosure that incorporates as many flexible features as possible to allow for easy customization for any application should be chosen. Flexible mounting features may include capabilities for interior customization or T-rails that allow brackets to be mounted in all four corners, accommodating a second or third mounting panel. Additional flexible features include the ability to directly mount a circuit board, antenna or hardware using brackets that mount in the four corners of the box for maximum versatility. The enclosure should also be equipped with bosses in the back or provide another way of affixing DIN rails, circuit boards or another electrical component to the rear wall of the enclosure.
A poly carbonate enclosure that can handle extreme outdoor environments.
Material Strength and Impact Resistance
While control and instrumentation enclosures were often traditionally constructed from steel or stainless steel, in the non-metallic category, enclosures made of fiberglass have now become a common choice for engineers. A newer but increasingly popular option is polycarbonate, which is four times stronger than fiberglass. This thermoplastic material is well-equipped to handle extreme, outdoor environments. Added benefits of the polycarbonate enclosures are that they are often the less expensive option, and they are easily modifiable, non-corrosive, non-conductive and lighter when compared to steel.
Many factors explain and support the growth of polycarbonate enclosures as the stronger alternative in the non-metallic category to fiberglass enclosures. Arising in the 1940s as the popular non-metallic enclosure material, fiberglass is an entrenched technology in the enclosure industry. However, the trend toward polycarbonate enclosures in Europe foreshadows and reflects growth of polycarbonate enclosures domestically due to superior material characteristics that are well-suited for outdoor applications, such as UV resistance, durability and lightweight nature.
Suited for temperatures ranging from -40 to 265 degrees, polycarbonate is specially engineered to handle a dramatic range of environmental conditions. In addition, the strength of polycarbonate is superior to alternative materials in that it will not warp. Enclosure warping is a common problem in the world of equipment protection, and it can compromise the enclosure’s security. Choosing a material that will not warp is another important consideration.
Aesthetics
Another factor is an enclosure’s construction and aesthetics. While some enclosures are bolted together at panel edges, molded plastic enclosures are available in a seamless shape that does not require bolts. Rather than the boxy look of welded metal enclosures, polycarbonate has the benefit of seamless molded, subtle curves and a precise, repeatable quality.
Hinges
Do not underestimate this important facet of an enclosure. Before making a selection, ensure that the enclosure’s hinges are easily accessed and able to be replaced when necessary. Hinges should also allow a wide-angle door swing. The enclosure’s door swing should open up at least 180 degrees, but an even wider angle —up to 225 degrees —will be an important benefit when the stored equipment must be serviced. Both metallic and non-metallic hinges are available, so consider again whether an antenna will be stored within the enclosure.
Completely non-metallic hinges will not interfere with radio signals. Hinges should also allow easy removal of the lid when the door is open. Depending on the enclosure material, hinge design may vary. Fiberglass enclosures have a metal hinge riveted on to the enclosure to hold the door. With some polycarbonate products, hinges feature an integral one-piece construction.
NEMA Rating
As would be expected, any enclosure considered for an outdoor application should be at a minimum NEMA 4X rated. NEMA 4X enclosures are suitable for either indoor or outdoor usage and will protect sensitive equipment against water and windblown foreign objects.
Consult an enclosure manufacturer with the specifics of the application and the environment in which the enclosure will be installed to best match the NEMA type needed to the environment’s demands.
While many guidelines can help make the enclosure purchasing process simpler, each pump monitoring application carries with it its own unique set of challenges, considerations and environmental conditions, which must be evaluated as a part of the overall selection.
The more accurately and detailed an application is assessed, the more likely a comprehensive and quality equipment protection solution has been selected.
Pumps & Systems, May 2012