What is the brass knob on my MQL system?

A single On/Off valve is located on the top block, regardless of the number of pumps or groups in your system. When the knob is pulled out, the fluid supply is off. This should be done when changing or adding pumps to your system. To turn the fluid supply back on, simply push the knob in.

Ensure the knob is in the ON position when the system is operating. If left in the OFF position, the pump will continue to stroke but won’t dispense fluid, which could shorten the lifespan of the internal components if run dry for extended periods