IECEx certification makes safe safer
Is the European standard of IECEx for harsh environment computers right for design engineers? How does this European standard impact U.S.-based operations?
While the phrase "IECEx certification" isn’t part of the daily conversation for systems engineers in the U.S., indications are that it may be soon. While the U.S. primarily uses Division-based systems, such as Underwriters Laboratories (UL) certification marks, for addressing hazardous areas and equipment, other countries have adopted the Zone-based IECEx system. The inconsistencies in hazardous area classification have made it difficult for U.S. manufacturers to tap into globalized markets, such as oil and gas processing. This has led to the shift toward global solutions that meet not only U.S. standards, but international ones as well.
What is an IECEx certification?
IECEx is an internationally recognized standard issued by the International Electrotechnical Commission (IEC) for equipment that is being used in areas that have an elevated risk for fires or explosions.
IECEx has made a slow entry into the U.S. because it is not currently a required standard in the country, and it increases the up-front cost of hazardous area computers because they require IECEx-approved components. These components typically cost up to four times more than their non-IECEx counterparts.
However, IECEx certification provides improved safety and long-term cost advantages that are unmatched by current certifications, such as UL certification marks, although testing is regulated by OSHA, UL is not globally accepted and does not require ongoing quality or facility audits. Other common certifications include; the class/division ratings based on the NFPA 496 (National Fire Protection Association), the NEC (National Electric Code), and the ATEX (Atmosphere Explosibles) Zone ratings. As a result of the improved safety and international recognition of the IECEx, more U.S.-based oil and gas processors in on- and offshore facilities are beginning to implement this standard.
Deciding whether or not to require that the hazardous area computers purchased for an offshore location meet IECEx standards, and then navigating the certification process is challenging for systems engineers.
First things first
The following five dynamics should be considered before taking the first step toward certification:
1. Is requiring hazardous area computers for the facility or location in question to be IECEx-certified a benefit to corporate operations?
IECEx certification is difficult, time-intensive, and costly to achieve, therefore few U.S. manufacturers of hazardous area and industrial computers have attempted to design and produce IECEx-approved complex computer systems. There are benefits of going through this process, but IECEx is not always necessary.
2. What is the nature of the environment where the computer is expected to operate?
In this case, the primary consideration is whether explosive locations would benefit from an IECEx-certified computer. Oil refineries, rigs, and processing plants certainly qualify with an increased risk of fire or explosions. In these areas, the failure of equipment can have unsafe and costly outcomes.
3. Is the computer designed to control other systems that require seamless operation?
Blowout preventers (BOPs) are typically controlled and monitored by IECEx-approved computers because of the many hazards and costs associated with blowouts. BOPs must go through frequent testing, so when paired with an IECEx-approved computer, the likelihood of a blowout-related emergency is decreased because IECEx performance standards are zero failure.
4. Is automatic failover capability critical to the hazardous area application?
Automatic failover provides reliability in the event of system failures or unplanned termination of the hardware or network. It is not required by IECEx. To date, an extremely limited number of U.S.-based hazardous computer manufacturers have incorporated this feature into an IECEx-approved system.
5. Is human error a potential risk for the computer’s application or operating environment?
Human errors occur and are costly. Prematurely sealing an oil well is a multi-billion-dollar mistake. Incorporating safety mechanisms, such as lock-out flip covers, protects against human errors. These additional protective measures and hardware must go through the IECEx-approval process.
Navigating the IECEx certification process
After an engineer has decided that IECEx compliance would benefit the design’s application, what happens next?
Step 1: Determine the appropriateness of IECEx for the design. If the area in question is prone to fires or explosions, IECEx would be applicable. For locations where system failures are extremely dangerous, these standards can prevent unnecessary accidents and expenses.
Step 2: Identify an experienced manufacturer to produce the computer. There are few manufacturers in the U.S. that have the capabilities, experience, and level of management that meet IECEx standards. These standards are difficult to meet because the manufacturer must undergo regular inspections to confirm that the facility is properly maintained, managed, and the products are equivalent to the original IECEx-certified design.
Step 3: Collaborate with the manufacturer on design. Because each component must meet certain standards, the manufacturer should be in complete understanding of the computer’s design. Creating a design spec without the assistance of the manufacturer can create problems in design and production, which drives up costs.
Step 4: Design the system. After a qualified manufacturer has been selected, design of the computer can begin and an IECEx application can be submitted. However, the engineer should be aware that the IEC will monitor the process.
Prior to production, the designer must submit an application to an appropriate IECEx certifier, also called an "ExCB." When a design engineer begins the process of achieving IECEx compliance for a hazardous area computer, he or she allows the IEC to control and monitor all aspects of the product’s design.
The ExCBs oversee all components of the computer including voltage, power consumption, spacing between the printed circuit board power supply, and ambient temperature range. All of these components must be documented and made available to the ExCBs by the engineer. The supervision and accreditation of the application is handled via an international peer review.
Upon application, the development of sample products begin, followed by thorough testing by a laboratory of the ExCB’s choosing. If engineers select components for their equipment that have been already approved by the IECEx, it can accelerate the testing process. If an IECEx-approved part is unavailable to fit the need, a non-IECEx-approved counterpart will be evaluated for compliance and complete design and manufacturing control must be demonstrated. Some of the key aspects tested for IECEx Zone 2 equipment samples include:
- A 28-day aging procedure on the enclosure prior to ingress protection (IP) testing
- IP grade is appropriate for the level of protection
- Enclosure, glass parts, and glass-to-metal sealing gaskets/compounds are satisfactory
- All external nonmetallic surfaces pass a static electricity test
- There are no unauthorized modifications (visible or nonvisible)
- Voltage and power levels are within the acceptable limits for the protection method
- Threaded enclosure covers are of correct type and are tight and secure (must pass visual and physical tests)
- Maximum surface temperatures of internal components are measured to confirm they will not ignite explosive gases and establish the thermal rating, or T-rating
- Automatic electrical protective devices are set correctly
- Safety cutoff devices function according to manufacturer’s documents
- Equipment is protected against corrosion, weather, vibration, and other adverse factors.
Equipment and facilities that have completed the process can be verified instantly via the international online certificate database that can be found on the official IECEx website. This expedites the procedure of validating that a product has met IECEx standards. Engineers often choose IECEx for their designs because in 2011, the United Nations, via United Nations Economic Commission for Europe (UNECE), endorsed it as an internationally-recognized certification process for the safety of equipment and personnel used explosive environments. Governments, safety regulators, and industries are guaranteed that the equipment being operated or supplied has met the most respected and dynamic safety protocols.
The sense of assurance and global recognition that comes as a result of IECEx can lead to additional cost-savings for the product as well. Designers can forgo the additional testing and certifications for their product to be sold. If a product is tested and approved by the IECEx standards, it complies with others such as NFPA, NEC, and ATEX standards as well because the IECEx process is more stringent. This decreases testing and certification costs associated with manufacturing, and time to market the product.
Michael Hadaway, general manager of Daisy Data Displays, has more than 10 years of mechanical engineering and product design experience. He received his B.S. in Mechanical Engineering and MBA from Pennsylvania State University.
Original content can be found at Control Engineering.