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The ammonia refrigeration industry is always changing, sometimes for the good and sometimes for the not so good. One of the changes is the coming and going of personnel. Workers get promoted, retire, or find different career paths, and new people are hired. With these changes, there is a constant need to train new people on all the systems. Some of these people will have a strong background in refrigeration while for others, it will be a completely new experience. This article is an operator’s perspective on ways to deal with this challenge for both the new hires and the veteran operators. For someone just entering this field, the question, “How and where do I begin?” will probably go through their mind. The first step will hopefully be an orientation session that will explain the company’s work rules, emergency action plans, facility layout, safety policies, and general procedures. Depending on the plant and staffing con- ditions, this could be a gradual training program on the plant’s systems or a crash course. Then the hard work begins! Hopefully the new operator will have a skilled and patient mentor who will show and explain the layout, how things operate, and what is expected of the operator. To the new operator, trying to learn the whole system all at once is a daunting task and will probably lead to frustration and questioning how can this actually be accomplished while maintaining one’s sanity. A way to approach this is to answer the question, “How do you eat a hippopotamus?”The obvious answer is: one bite at a time. The same applies to learning the ammonia system. Firstly, depending on the new operator’s experience, learning the basic refrigeration cycle will help with the understanding of how the system components work together. The next step is to locate and use the Piping and Instrumentation Drawings (P&IDs) and Standard Operating Procedures (SOPs) to learn the system. The SOPs detail how to operate the piece of equipment, including starting, shut down, valve positions, operating parameters, emergency procedures, and preparing the equipment for maintenance.

P&IDs illustrate the piping and valve layouts. This drawing is the road map of the system. P&IDs show the position of the valves (normally open or normally closed), pressure and temperature gages, transducers, pressure switches, and level switches, just to name a few. P&IDs are used in conjunction with SOPs to safely operate and maintain the ammonia system. By familiarizing yourself with these documents and using them in the learning process, the road to learning the system becomes considerably easier. Borrowing from my submarine days when I would go for a Systems Qualification Check-out, one of the first tasks was to draw the system. While one would not expect a person to recreate the whole P&ID from memory, being able to draw the valve group from a single evaporator is a building block to understanding the whole system. Learning the system in small bites makes the task much more manageable. The experienced operator should take the trainee with them when adjusting a machine and when performing planned or corrective maintenance. After the job is completed, take the component (such as a valve) that is going to be thrown away and

AN OPERATOR’S PERSPECTIVE OF AMMONIA REFRIGERATION By Gordon Rascoe

24 RETA.com