AMMONIA RECEIVER : Ammonia receiver can control the supply and demand relation between the condensers and the evaporator, prevent excessive liquid ammonia from staying in the condenser, maintain a certain level in the liquid receiver to prevent gas from going into the liquid pipe line. The ammonia in the system can be stored in the ammonia receiver to avoid loss of the ammonia before the refrigerating system is repaired. Therefore, the volume of the ammonia storage should be considered before buying it.