The Best of Extra Edition: July 29, 2013
The thermostatic expansion valve (TEV or TXV) is erroneously considered by some to be a mysterious and complex device. As a result, many valves are needlessly replaced when the cause of the system malfunction is not immediately recognized. Actually, the TEV performs only one very simple function – it keeps the evaporator supplied with enough refrigerant to satisfy all load conditions. It is not a temperature control, suction pressure control, a control to vary the compressor’s running time, or a humidity control.
Filter driers play a pivotal role in the operation of air conditioning and refrigeration systems. At the heart of the unit is the desiccant, held in its cylindrical metal container. Desiccant is the material that accomplishes the moisture removal. Moisture in the mechanical refrigeration cycle is detrimental to the operation and life of the system. The filter drier is an accessory that performs the functions of filtering out particles and removing and holding moisture to prevent it from circulating through the system.
A clean motor is a happy motor. As any service technician knows from experience, contamination is one of the leading causes of premature motor failure. The biggest challenge, from a service standpoint, is that motors typically spend their working lives unseen, either covered or installed in an enclosed area, such as inside a furnace. A lot of mischief can take place away from watchful eyes, and the knowledgeable service technician must be prepared to go beyond treating the most obvious cause of motor problems.
Oil-flooded screw compressors use oil for lubricating bearings and internal components, sealing internal rotating components to maximize efficiency, and absorbing the heat of compression during the compression process. How do you choose the best oil cooler for your customer’s application? Become acquainted with the design, components, and benefits of various systems on the market.
The only thing worse than wading through a business downturn is to do so without a strategy. “Business as usual” doesn’t cut it when markets, consumers, or other conditions beyond your control turn against you. The old saw, “What doesn’t kill you makes you stronger,” is little consolation when business is slow. Follow the seven steps highlighted in this article to stay up in down times.
Publication date: 7/29/2013