1. Once Thru Systems:  These systems are design with a water seal which is wasted to drain once it is exhausted from the vacuum pump.  These systems are economical and require little maintenance but especially with larger pumps can consume large quantities of water. All our close-coupled NCC series vacuum pumps can be fitted with our exclusive Water-Saver™ discharge separators which can recover between 40-50% of seal water.

2. Partial Recovery Systems: These systems are designed to recover up to 50% of seal water and are only slightly more expensive than once-thru systems. We recovering seal water care must be taken to avoid over heating the pump as process heat and heat from compression are captured in the seal fluid.  Temperature of seal water should not exceed approximately 175F as a general rule.  Higher temperatures are possible using alternative seal fluids but pump performance is inversely related to temperature as a general rule.

3.Full Recovery systems (Self-Contained): These systems are designed to be 100% self contained by fully re-circulating the seal fluid. This is often desirable where water usage is limited or the process requires a closed system.  As a result of constantly circulating the seal fluid, these systems require some method of heat extraction to remove excessive process heat and heat from compression.  Heat extraction is typically accomplished by way of a centrally cooled or air-cooled heat exchanger. Self contained systems require planned maintenance to ensure the seal fluid is free of debris and contamination.

Please read the following white paper to learn more about these systems:    How To Install A Liquid Ring Vacuum Pump