What are the two most common ammonia refrigeration compressors?

• A. Centrifugal and scroll compressors
• B. Reciprocating and screw compressors
• C. Rotary and piston compressors
• D. Diaphragm and vane compressors

Answer: (B)

Ammonia refrigeration systems rely on compressors that are rugged, reliable, and well-suited to ammonia’s lubrication and sealing needs. The two most common types are reciprocating (piston) and screw compressors. Reciprocating units have long been the workhorses of ammonia plants: they’re robust, easy to maintain, and perform well across a wide range of capacities and pressures, which makes them reliable for varying loads and mission-critical service. Screw compressors, on the other hand, excel at large capacities with smooth, continuous operation and good efficiency at high loads; their design handles the continuous duty typical of larger ammonia plants and pairs well with oil-injected lubrication used in ammonia service. Other compressor types exist for different applications, but they’re not as commonly used in standard ammonia refrigeration setups due to practicality, efficiency, or sealing challenges in ammonia.