Compression Capability
Rotary Vane Compressor
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
Reciprocating Compressor
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
Oil
Rotary Vane Compressor
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
Reciprocating 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
Power
Rotary Vane Compressor
Rotary vane compressors can be used with a Variable Frequency Drive to maximize operational efficiency.
Reciprocating Compressor
Reciprocating compressors can be used with a variable frequency drive and unloading devices to maximize efficiency
Cooling
Rotary Vane Compressor
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
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.
Gas Composition Tolerance
Rotary Vane Compressor
Rotary Vane compressors can tolerate almost any gas, as well as varying compositions with standard metallurgy
Reciprocating Compressor
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.
Capacity Control
Rotary Vane Compressor
Sliding vane capacity control is most commonly implemented via a variable speed drive (VSD) or gas recycle loop.
Reciprocating Compressor
Reciprocating compressor capacity is most often controlled by speed control.
Field Service
Rotary Vane Compressor
Hand tools are needed for basic maintenance. A complete repair can be completed by properly trained machine shops.
Reciprocating Compressor
Reciprocating compressor have significantly more moving parts than rotary compressors.