Cold Link Africa March/April 2019 | Page 45

FEATURE INCORPORATING COLD CHAIN Compliance and conformity – some misconceptions By John Ackermann ervice technicians are at greater risk when repairing or servicing such pressurised equipment if not properly trained to do same. Injuries can stem from burst piping, component failure, explosions, or due to asphyxiation. All systems have the potential of catastrophic failure in the event of excessive high pressure due to human error, component failure, or the absence of safety components, for example pressure relief valves. NOT ALL REFRIGERANTS ARE EQUAL There is a misconception that only ammonia plants require certificates of conformity and need to follow the requirements of the PER. REGULATIONS ARE THERE FOR A REASON To prevent such unfortunate incidents, a number of codes and standards have been drafted and promulgated, including SANS 10147, the Pressure Equipment Regulations (PER), and the OHS Act. Although each is referenced to one another, the purpose and the focus are In addition to the risk from excessive pressures, each refrigerant used in systems has a unique risk due to its toxicity and flammability. ASHRAE Standard 34 rates each refrigerant A for non-toxic or B for toxic and the numeral 1 to 3 for its level of flammability. R22 has a toxicity rating of A and ammonia B. Under certain concentrations, ammonia will be explosive and has a rating of B2L, while R22 is rated as A1, or in layman terms, is odourless and non- explosive. The 2L of ammonia indicates that at certain concentration levels and under certain conditions, it is explosive. Propane (R290), with a rating of A3, is odourless, but highly explosive. It must not be overlooked that even ‘safe refrigerants’ such as R22 with a rating of A1 can indirectly cause fatal harm. A death reportedly occurred when a service technician entered the hold of a fishing vessel to diagnose the failure of a R22 refrigeration system. The malfunctioning of the plant was due to a leak in the evaporator. The leaked R22 gas collected in the hold and reduced the oxygen level. Due to the lack of oxygen and not being able to smell the odourless R22, the technician lost consciousness and collapsed while in the restricted space of the hold. It was only much later that he was found by a fellow crew member, but by then he had passed away. Admittedly, the mentioned death was not directly as a result of R22 being harmful, but due to lack of workplace safety procedures and proper training; in other words: do not enter confined areas alone or without notice given to another person who can be alerted by way of rope or the like. Safety equipment such as automatic gas detectors fitted in the hold would also have prevented the unfortunate death. Sadly, there have been more than one such tragic incidence of persons working on R22 systems, reported along the South African coastline. S All closed-circuit refrigeration and air-conditioning systems, by way of being pressurised, pose a risk to the safety of persons close to it. Training in the safe handling of refrigerants and proof of competency are requirements for SAQCC Gas registration in category B. Pressure vessels in supermarket installations with synthetic refrigerants also require certificates of conformity and certificates of compliance to be issued by those who charge and pressure test. clear: to safeguard the safety of persons who install, service, and repair HVAC&R systems and to ensure that all system components and equipment are able to safely withstand the duty and operating conditions to which subjected. It is also of importance that the system is able to withstand any build-up of pressure when the plant is idle. In simple terms, the regulations require that the design, installation, and components comply with the minimum safety standards and is certified through the issue of a certificate of conformity by authorities or persons who are conversant COLD LINK AFRICA • March/April 2019 with the regulations and have the knowledge to issue such certificates. CERTIFICATE OF CONFORMITY VS CERTIFICATE OF COMPLIANCE The PER requires that persons who service, maintain, or repair the pressurised circuit of the system be suitably trained and certified to perform such tasks. On completion of such work, the technician is required to complete and sign a certificate of compliance stating that all work had been done in accordance with the regulations. Continued on page 47 www.coldlinkafrica.co.za 45