Understanding how and why gas ballast is crucial for oil-sealed rotary vane vacuum pumps is vital. It can be challenging to establish the precise reasons why it is no longer common, but one crucial aspect may be a misperception of how gas ballast valves operate.
The science of gas ballasting is simple. However, something important appears to have been lost in translation since these vacuum pump accessories were designed in 1935. Gas ballast use would undoubtedly improve if more users knew how they function and how they may help their vacuum pump systems.
What is the Function of the Gas Ballast? 
The gas ballast should typically remain on while the vacuum pump draws in vapor. When pumping vapor, the ultimate pressure of the vacuum pump will be constrained by the vapor pressure of the substance being processed rather than the pump's pressure capability. You must be careful to avoid introducing air/oxygen if any of the process components are combustible.
How Does Water Vapor Impact My Vacuum Pump?
Water vapor is one of the most common vapors that vacuum pumps manage. The lowest pressure the pump can reach before all the water has been pushed away is 24 mbar (18 Torr), which is the saturated vapor pressure of water at 20 oC (70 oF). Allowing water vapor to condense within a pump increases the time required to regain ultimate pressure compared to leaving it in the vapor phase.
It is because it must be re-evaporated before it can be pumped out, which requires significantly more energy and time than if the water remains in the vapor phase. Condensed water vapor may also swiftly damage the oil in an oil-sealed rotary vane pump.
Edwards Mode Switch: An Innovative Feature for Dealing with Condensable.
The Edwards RV series of oil-sealed rotary vane pumps feature a one-of-a-kind mode switch' option that allows for rapid oil conditioning after exposure to condensation. The Maximum Water Vapour Handling Capacity of vacuum pumps is generally specified in grams/hour. The amount of gas used for ballast, the pump's operating temperature, and the pressure at which the exhaust valve opens all affect this characteristic.
As you can see, gas ballasts are essential for an Oil-Sealed Rotary Vane Pump's performance. When used with an oil-sealed vacuum pump, they minimize the vapor condensation, and thus contamination, of the pump's sealing oil. If you are interested in learning more about this vacuum pump or are having trouble choosing one, our team can help. We offer outstanding Edwards oil-sealed rotary vane vacuum pumps to fit your demands. Contact us for more information!