What is the difference between valve-regulated and Vario (speed-regulated) control?

You can choose between valve-regulated and Vario (also known as RPM or speed regulated) vacuum pumps for a rotary evaporator (depending on the rotary evaporator configuration you choose).

Valve regulated pumps control the vacuum by opening and closing a valve. The vacuum pump runs at full power at all times; when the vacuum reaches a specific level, the valve is triggered, which opens and releases some of the vacuum.  This is a simple, low cost option.

Vario vacuum pumps can alter their pumping speed (rpm), offering more precise control of the vacuum and lets the user set their required vacuum level.

The advantages of Vario pumps over valve-regulated ones include:

• Increased energy efficiency
• Increased solvent recovery rate
• Reduced bumping/foaming
• Reduced noise and vibration
• Reduced wear on the pump – increased lifetime