Hazardous Area Access Point Enclosures for Safety, Reliability, Convenience and Cost Savings

Industrial wireless networks are a much-needed solution for hazardous areas where wired connections are impossible. Wireless networks are also an ideal choice for temporary or mobile applications.

Industrial Wireless Networking is a newer technology quickly becoming the standard for companies that need to transmit data wirelessly in hazardous areas. Industrial wireless networks are gaining traction in hazardous areas with distinct advantages over hard wiring. However, some disadvantages make it less desirable than hard wiring.

Industrial wireless networks are a cost-effective solution to provide reliable, secure, and fast internet access in hazardous areas. In recent years, the demand for industrial networks increased with the increasing popularity of IoT (Internet of Things). This industrial network segment is seeing a surge in demand as more instruments and supervisory control systems connect their devices to the Internet.

Wireless has been a solution to many challenges faced in industrial networking, from remote locations to temporary installations, with the convenience of mobility and reduced installation costs.  

An access point is a device that establishes a wireless local area network, often known as a WLAN. An access point uses Ethernet to connect to a wired router, switch, or hub and broadcasts a WiFi signal to a specific region of a building or plant. However, a significant challenge remains: how to prevent access points from causing ignition and protect the access point against harsh environmental conditions? 

Hazardous Access Point Enclosures are enclosures used to protect wireless access points in hazardous areas. They provide safety to the wireless network equipment and the people who work in the area.

Some of the hazards that might be present in a hazardous area include combustible gases, oxygen-rich atmospheres, and flammable dusts. These hazards can cause a fire or explosion if they come into contact with an open flame, spark, or heat source.

To ensure that access point devices can operate reliably in hazardous environments such as oil rigs or chemical plants, they need protection from combustible gases, dust particles, and corrosive chemicals.

The need for Hazardous Access Point Enclosures is increasing daily due to new wireless network technology and are a requirement for all access points operating in hazardous industrial areas. These enclosures protect the access points from dangerous areas and environments. They have various features to ensure the environment is protected and secure for the personnel working in the area.

Some of these features include:

• Compliance with international standards
• Resistance to extreme temperatures
• Permits installation in any location within a hazardous area
• Protection against dust and water ingress

Industrial wireless networks have a lot of benefits over hard wiring. The lack of wires makes installing and moving around in hazardous areas easy. In addition, you can eliminate the cost and hassle of having to replace or repair wires if they break or get cut. Access points are critical components of industrial networks, and Hazardous Area Enclosures are an essential safety measure for access point manufacturers when applying their products in these settings.

Wireless for Safety

Wireless systems may be useful to enhancing the safety profile within a factory operation. These systems can be used to prevent injury through improved communication and enhanced situational awareness within the factory. Wireless safety systems are used in many applications including those designed to prevent chemical handling mishaps, avoid heavy equipment accidents such as “struck-by, and back-over” incidents, prevent falls through active position monitoring and safety interconnects, provide situational awareness within confined spaces, and improve safety for non-employees.

Along with adaption of wireless sensor networks for industrial automation, there are more applications of wireless technology created by users after they are more familiar and comfortable with the wireless technology. Also because of the strong benefits of wireless applications that can save project execution time and cost, more and more wireless has been used for secondary or backup systems for time-critical application such as safety or control applications. Based on this movement, ISA-84 working group (WG) 8 developed a technical report on wireless for safety systems other than those of a safety integrated system (SIS), i.e., those systems with a system integrity level (SIL) rating below ten. The technical report describes the additional elements needed to be addressed when wireless technology is used in an Independent Protection Layer (IPL). Refer to the ISA technical report TR84.00.08-2017 Guidance for Application of Wireless Sensor Technology to Non-SIS Independent Protection Layers for more information.

Reprinted from "Guide to Industrial Wireless Systems Deployments" by the National Institute of Standards and Technology. Get your copy here.

Analynk Wireless: Instrumentation for the Process Control Industry

Analynk Wireless is an innovative designer and supplier of wireless instrumentation for the process control industry. Our instruments have been successfully implemented in several applications including temperature measurements 4 to 20mA bridges, discrete inputs/outputs, pulse inputs, lighting and pump controls. These products have been used in both hazardous and non-hazardous locations. Analynk Wireless also manufactures a line of traditional wired instrumentation; see Telmar Instruments for details.

Developing a Useful Alarm Strategy

Industrial process at pharmaceutical plant

Industrial process control operators and designers have the capability to measure many aspects of machine operation and process performance. Determining the elements to measure, method of measurement, and how to handle and process the derived information can be challenging, but can also impact the security, performance, and safety of an operation. A plan for monitoring, reporting, and responding to abnormal process conditions, if properly developed and executed, can yield real benefits to a process operator. A protocol that is not well conceived may produce a negative operational impact by creating events that unnecessarily draw resources away from productive endeavor. That protocol, or plan, is often referred to as an alarm plan.

There are numerous forces that can influence the development and implementation of an alarm plan. Each operation must incorporate its own set of external regulatory requirements, internal procedures and policies into a complete alarm protocol. Distilling that macro description down to a workable set of procedures and response tasks is where the real work begins. There is, however, a basic framework that can help organize your thinking and focus on what is most important.

• What parameters define the process or operation?
  Produce a schedule of every non-human element that is required to make the process function. This will require drilling down through every machine and material that is part of the operation. Expect the schedule to be extensive, even huge. If it is not, consider that your analysis may not be reaching deep enough. The goal here is to create an overview of what makes the process work and provide a tool for systematically studying the process elements and gleaning possible commonalities or relationships among them. Consider disregarding things that cannot be measured, since that prevents the derivation of data for evaluation. Review the completed schedule and decide which parameters shall be measured and evaluated for proper performance.
• What level of measurement is needed for each monitored parameter?
  An assessment of the needed accuracy, frequency, and resolution for parameter measurement will help define the requirements for instrumentation or other devices used to monitor a particular item. The goal is to make sure the monitoring device is capable of detecting and delivering information of sufficient quality to make decisions.
• Define the limits of acceptability for each monitored parameter.
  Until the endpoint of the process or operation, each step is likely dependent in some way on previous steps. The output of each step becomes the input of the next. While this, in many cases, may be an oversimplification, it is important to consider the relationships between the

  

  High speed filling operation

  tasks and operations that comprise the process. Monitored parameters should relate to the successful completion of a process step, though not necessarily be a direct indicator of success. The maintenance of the parameter within certain bounds may be used as an indicator that a component of successful completion was properly attained. Defining limits of acceptability may involve an element of subjectivity and will likely be customized to accommodate the process. Each organization shall evaluate their operation and determine limits based upon intimate process knowledge and experience.
• Define abnormal operation for each monitored parameter.
  Abnormal operation may not necessarily be any value not within what is considered acceptable. Consider abnormal to be the range of values that would be cause for notification of the operator, or even automated or human intervention. Note that the definition of unacceptable or abnormal operation might appropriately include filters or defined relationships with other parameters. An example of a simple filter is a time delay. If the measured variable exceeds the specified limit for 2 seconds, it make not be significant. If the threshold is exceeded for 2 minutes, it may be cause to take action. As with the limits of acceptability, developing the definition of abnormal operation for each parameter will be customized for each process.
• Provide a defined response for every alarm occurrence.
  If it is important to monitor something, then it is likely important to do something when things get out of hand. Human executed alarm response should be concise and uncomplicated, to reduce the probability of error. Automated response should be designed in a manner that provides for functional testing on a regular basis. The scope of the response will be specific for each process, with the level of response depending upon factors determined by the process operators. Response can be as simple as annunciating the condition at a monitoring station, or as dire as shutting down part or all of the process operation.
• Review every alarm occurrence
  Each alarm event should be logged and reviewed. Consider whether the event detection and response was adequate and beneficial. If the results were less than expected or desired, assess whether changes can be made to provide improved results in the future. The alarm plan is unlikely to be perfect in its first incarnation. Be prepared to reevaluate and make changes to improve performance.

The exercise of developing a comprehensive alarm plan will help to build understanding of process operation for all involved parties. This article is but a brief synopsis of the subject, intended to get the reader on the path of developing a useful alarm plan. Your alarm plan should an extension of process operation decision making, and have a goal of enhancing safety and reducing loss.