Most models may also be equipped with a diaphragm vacuum safety (DVS) enhancement. This offers additional protection against diaphragm rupture in any condition that results in excess vacuum on the pump inlet. The flow rate is controlled by varying the speed of the motor with a variable-frequency drive (VFD). Any changes can be easily implemented while the unit is running, either locally at the device or remotely using a 4-20mA signal. The Series MD can accommodate a variety of motors, ensuring compliance to any stringent electrical requirements. Every aspect of the construction of this pump ensures high stability, low downtime, and the immense dependability that CheckPoint consistently guarantees.