Water contamination has many effects on an ammonia refrigeration system. The pressure-temperature relationship becomes impaired. The compressor oil begins forming organic acids and sludge from a complex chemical reaction. Pressure drops increase through piping. Pump and evaporator performance are adversely affected. The system must be operated at a lower suction pressure to maintain the desired room temperatures or to handle the same processing system loads. As the suction pressure is lowered, this increases the BHP/ton, causing less compressor capacity and increasing power consumption.
But, how does water even enter the ammonia refrigeration system? Water can gain entrance into the system in many ways. Systems that operate with the suction pressure in a vacuum are the most common source. Leaks from valve stem packings, screwed and flanged piping joints, threaded and welded pipe connections, leaking safety relief valves, pump seals, booster compressor seals and deteriorated piping and evaporator coils become sources of infiltration.