In any case, the ability to reduce the time required for cer- tain phases of the turnaround while making the turnaround less complicated by taking traditional maintenance func- tions off the ‘critical path’ using temporary cooling solutions can reduce costs for certain turnaround stages, including: • Steam-out • Deinventorying • Decoupling • Catalyst cooling. In addition, engineered temporary cooling solutions to optimise process conditions during critical periods of the year can avoid production interruptions while minimising non-productive capital assets. Whether for turnarounds or critical operational periods of the year, the benefit-to-cost ratio rendered by using engineered temporary cooling solutions (such as improving amine systems’ H₂S and CO₂ recovery efficiency to avoid fouling and elevated corrosion rates) is worthy of the indus- try’s direct interest.
cal/cm 2 PPE- rated clothing to be worn anywhere in the plant. As a relative measure, 1.2 cal/cm 2 is the amount of energy exposure that will result in a second-degree burn (or less), whereas anywhere from 4 to 8 cal/cm 2 is the threshold range resulting in more severe injuries, including third- degree burns or death. According to information from experts at Aggreko Process Services, equal training for all its technicians, ranging from live testing and troubleshooting to the use of thermal imaging cameras, is founded on the premise that electrical assets should always be treated as if they are live until the assets are LOTO’ed. This is an important safety consideration because an electrical system cannot be ‘designed out’ to be ‘non-electric’. Risk matrix The application of a risk matrix such as Aggreko’s “Safety for Life” Low Voltage Shock and Arc-Flash Risk Matrix (Release 09.20.17) was developed from the best practices and risk assessment techniques of NPFA-70e-2017 and IEEE-1584a/b/c. 1 These techniques contribute to a useful risk assessment methodology in many of Aggreko’s com- mercial and industrial applications. However, the more levels in a matrix, the more com- plicated the matrix is to use, which is why Aggreko’s risk assessment matrix focuses specifically on power-consum - ing ‘utilisation equipment’ (chillers, dehumidifiers, A/Cs, air handlers, cooling towers, heaters, compressors) and distri- bution equipment (panel boards, load centres, switchgear, circuit breakers). Consensus approach An electrical system, as necessary as it may be, should indeed be designed out if it is deemed unsafe. Therefore, a big part of the strategy Aggreko pursued when revamping its electrical safety programme involved the introduction of administrative controls, engineering controls, and focus on PPE. So, in addition to incorporating general safety standards required by OSHA (and legally enforced), Aggreko has incorporated many of the electrical safety components from NFPA-70e, even though they may not be required by law. Going forwards, NFPA-70e has evolved as the de facto ‘consensus’ for upgrading electrical safety standards in the industry.² Above all, developing an electrical safety strategy based on NFPA-70e coincides with expectations that the indus- try will incorporate significantly higher levels of electrified systems. References 1 The IEEE Std 1584-2002 is a standard of the Institute of Electrical and Electronics Engineers that provides a method of calculating the incident energy (in cal/cm 2) of an arc flash event. 2 The background behind NFPA-70e began in the 1970s when OSHA contracted NFPA to write an electrical safe work practice standard.
Rene Gonzalez, PTQ
Electrical safety in the refinery and petrochemical workplace
Prior to the pandemic, the industry may not have required any electrical arc flash-rated equipment, whether it was gloves or other personal protective products (PPP). However, it was a standard process for ‘LOTO’ equipment (LOTO: lock-out and tag-out), but that process wasn’t enforced all the time. The industry began fast-tracking ways to increase its level of electrical safety by making employees more aware of the consequences of electrical hazards such as shock and arc flash. Electrical safety is especially poignant when personnel work alone or in an isolated area of the plant (tank storage, FCC unit, coker). Regardless of the circumstances, just because somebody understands what procedure is required for a certain task, if they don’t know why “it is the way it is,” they are less likely to follow the procedure when no one is looking! An electrical incident can lead to negative consequences in a fraction of a second. According to the National Fire Protection Association (NFPA), hundreds of deaths and thousands of burn injuries occur yearly due to shock, elec- trocution, arc flash and arc blast, and most could be pre - vented through compliance with NFPA-70e: Standard for Electrical Safety in the Workplace. In various plant settings, site-specific training is required before a contractor or supplier’s employees are allowed into the plant to perform any services or engineering. This is particularly crucial for a revamp with a 24/7 schedule of functions involving multiple ‘outside’ contractors. Typical requirements involve one day of training for basic safety awareness plus another half-day of training for site-specific plant functions. In addition, most refinery and petrochemical facilities now require a minimum of 8
Rene Gonzalez, PTQ
95
PTQ Q3 2022
www.digitalrefining.com
Powered by FlippingBook