Rescuing a leaking reefer unit
before frozen mango load thaws
Sep 30, 2010 7:00 AM
ServiPartes gave a whole new meaning to “wholesale customer service” when branch manager Karina Rodriguez reopened the heating, ventilation, air-conditioning/refrigeration (HVAC/R) distributor’s Mexico City store late one night just to retrieve emergency refrigeration supplies.
The extraordinary act of customer service helped a panicked service tech repair a semitrailer truck’s leaking refrigeration unit that was no longer cooling US $100,000 worth of quickly thawing frozen mangoes.
Midway between Cancun and his Aguascalientes, Mexico destination, the truck driver for wholesale food distributor La Huerta realized the 53-foot-long container truck’s interior temperature was climbing above the prescribed frozen produce temperature requirement of –25° F (–31° C). The La Huerta dispatcher found a 24/7 reefer repair shop in nearby Mexico City; however the reefer’s leak-causing compressor gasket replacement wasn’t in stock.
Finding an available truck and the labor for a late-night transfer of 60 tons of mangoes wasn’t possible. However, reefer service tech Edgar Ramirez recalled Rodriguez’s recent sales pitch on a newly stocked ServiPartes product, Super Seal refrigeration sealants by Cliplight Mfg, Toronto. Rodriguez told him the sealant might get him out of a difficult situation someday if a leak couldn’t be fixed conventionally or wasn’t accessible.
“I never dreamed it would be 60 tons of thawing mangoes,” said Ramirez, a veteran refrigeration technician.
Antonio Estevez, general manager for the nine-branch ServiPartes, which is a division of Estado de Mexico-based Trane Mexico, called Rodriguez at home for a late-night store reopening to get two cans of leak sealant for a distressed but loyal customer. Rodriguez, who is trained on sealing basics, offered a few tips and provided a sealant formula designed for units of more than five tons.
High-tech HVAC/R sealants are totally different than automotive air-conditioning sealants. They come in various doses for any size refrigeration unit ranging from consumer appliances up to large multiple-ton building chillers.
“HVAC sealants were invented about eight years ago, and there are more than one million successful applications so far,” said Jorge Bustamante, director of product sales, Fidelitone Logistics, Wauconda IL, a global third-party supplier of logistics and solutions, and Cliplight’s exclusive distributor for Mexico, Central America, South America, and the Caribbean. “A reefer might have a different configuration for the transportation business, but its refrigeration cycle and components are identical to a rooftop air-conditioners, chillers, or any other refrigeration units, so sealing a leak requires the same process.”
Ramirez started by recovering the reefer’s remaining R-404a refrigerant—which was 50% depleted—and evacuated the empty system under a vacuum to boil off any residual moisture. Since sealants are combinations of organosilanes that react to external atmospheric moisture to bond the microscopic hole they leak out of along with the refrigerant, eliminating internal system moisture is the key to a successful sealing. The sealant process is similar to blood leaking from a human body wound and eventually coagulating to form a leakproof scab.
After following the 16-step illustrated processes of recovery, evacuation, preparation, and sealant injection of one three-ounce can for a 30,000-Btu unit, Ramirez recharged the reefer with refrigerant. Within minutes it was recording original specification pressures on his gauges.
Ramirez, who now inventories sealants along with his other arsenal of refrigeration tools, said the two-hour repair was successful and the La Huerta truck was once again motoring down the highway toward its headquarters with a frozen load of mangoes.
If another leak of 300 microns or smaller develops in the future, the residual liquid sealant in the system will most likely bond it, according to Bustamante. La Huerta reported the reefer was operating like new and the mangoes remained frozen when the truck arrived. While sealant bonds typically last years, La Huerta eventually ordered and replaced the compressor gasket at its own convenience.
For ServiPartes’ general manager and branch manager, their extraordinary customer service act probably gained the reefer service company and trucking company as lifetime customers. Visit www.cliplight.com to learn more.
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