In order to press ammonia and the intermediate carbamate into the reactor, high pressure is necessary. The high-pressure pumps must deliver operating pressures of 140 to 240 bar. At the same time, large plants require ammoniac flow rates of 2,000 liters per minute or higher.
The pumps work in hard 24-hour continuous operation and require maintenance for long periods of time. Carbamate is very aggressive and corrosive. High process temperature up to is required to keep the carbamate in a liquid state of aggregation. Crystallation of the process media in the sealing area of the liquid end must be avoided at all cost.
The design of the ammonia pump must take into account the special properties of a liquefied gas. Liquid ammonia has poor lubricating properties and has higher compressibility than water. Operational reliability is extremely important. When ammonia is released, a huge volume of gas is created, displacing oxygen and freezing the surroundings. This represents an extreme risk to all persons in the immediate vicinity.