Ammonia is a cost-effective and efficient refrigerant. The only drawback is its classification as a poisonous refrigerant that in case of leakage can be harmful to personnel and the food items that the refrigeration system was designed to protect.
The risk of leaks arises from many different sources, ranging from inadequate operating procedures or lack of training to failures in piping, welds or poor maintenance.
Due to its classification as a poisonous gas, design, construction and operation of ammonia refrigeration systems are governed by strict standards. Early-warning detection devices, efficient ventilation systems, emergency switch-off systems are among the typical measures implemented to limit the risk during operation.
Reduce the Number of Welds to Reduce Risk of Leakage
But the risk of leakage can also be reduced in the design of the refrigeration system. Placing ammonia refrigeration equipment in separate rooms and with vapor tight separations are basic design parameters. Considering that quite a few leakages result from poor welding, the weld quality or reducing the number of field welds can also be an effective measure to prevent leaks.
By using valve stations where shut-off valves, strainers, check valves, solenoid valves, hand expansion valves and motorized valves are built into one integrated unit, the number of field welds is reduced significantly. Valve stations are delivered pre-tested to the highest safety standards from the factory, and only two field welds are needed to build them into the refrigeration system. This means that the risk of leakage resulting from poor welding decreases considerably.
Danfoss is a leading provider of integrated and compact valve stations. The ICF range of valve stations is a compact replacement for large, welded valve trains. One of the primary advantages of the ICF solution is the reduced leak potential resulting from only two field welds when the station is built into the refrigeration system.
