Rotary Vane compressors manage ratios up to 7:1 in compression applications.
Ro-Flo rotary vanes have a MAWP of 200 psig (13.6 barg).
Rotary Vane compressors are not sensitive to inlet pressures
A single stage of a reciprocating compressor can typically manage a ratio of about 3:1. The ‘recip’ compressor uses multiple stages of compression to reach extremely high overall ratios
The multi-stage recip compressors can reach discharge pressures of 5000 psig and beyond
Recip compressors struggle with low inlet pressures (< 50 psig) and deep vacuum applications due to dew point concerns and valve losses
Rotary vanes require a small amount of oil which is intermittently injected for lubrication purposes
Rotary vane lubricant is usually coalesced and captured downstream of the compressor
The recip compressor has a once through continuously injected system for the cylinder bore and piston components.
The recip compressor also has a recirculating system for the bearings, bushings, thrust plates and crossheads
Recip lubricant is usually captured downstream of the compressor
Rotary vane compressors can be used with a Variable Frequency Drive to maximize operational efficiency.
Reciprocating compressors can be used with a variable frequency drive and unloading devices to maximize efficiency
Ro-Flo sliding vane compressors are water jacketed to provide thermal stabilization of the cylinder and remove heat from the bearings.
Process gas is typically cooled by a heat exchanger downstream of the compressor
Reciprocating compressor cylinders may or may not be cooled. Compressor crankcase oil will typically need to be cooled.
Process gas is typically cooled by a gas-air heat exchanger.
Rotary Vane compressors can tolerate almost any gas, as well as varying compositions with standard metallurgy
Reciprocating compressors can tolerate minor changes in gas composition/molecular weight. Significant change requires valve modifications.
Reciprocating compressor components require special metalurgy for sour gas and acid gas applications.
Sliding vane capacity control is most commonly implemented via a variable speed drive (VSD) or gas recycle loop.
Reciprocating compressor capacity is most often controlled by speed control.
Hand tools are needed for basic maintenance. A complete repair can be completed by properly trained machine shops.
Reciprocating compressor have significantly more moving parts than rotary compressors.