Truckmounted carpet cleaning machines rely on air movement (flow) to remove spent cleaning solution, water, and debris from soiled carpets.

This air movement is produced by mechanical means inside the truckmount. A vacuum (latin vacuus, meaning vacant) pump is used to create the movement of air. These pumps are also called ‘blowers’ because they ‘blow’ air out of the exhaust. The movement of air through the pump creates a negative pressure (vacuum) on the inlet, and a positive pressure on the outlet. The negative pressure side of the pump is plumbed to a tank that is used to capture the water solution being removed from the cleaning process.

The ‘vacuum’ tank is constructed of aluminum and has internal baffles and structures to support the negative pressure environment created by the vacuum pump.

Since the vacuum pumps utilized in most truck mounted carpet cleaning machines are what they call ‘positive displacement’ devices, and they can produce much more vacuum pressure than is practical for the carpet cleaning process. In order to safeguard the integrity of the aluminum vacuum tank and the associated components a ‘vacuum relief valve’ is installed in the tank to limit the negative pressure environment to specific levels.

The vacuum pressure limits are set by the manufacturer of the vacuum pump and the manufacturer of the carpet cleaning equipment to protect the components from damage due to excessive pressure on the aluminum tanks, excessive heat in the vacuum pump (they are ‘air cooled’, cooled by the air passing through the pump), and excessive loads on the driving components (engine, or drive shafts).

Extensive research and validation testing goes into choosing the proper vacuum pressure limits of each machine.

Changing the factory vacuum settings may result in damage to many of the machines’ critical internal components and is not covered by most machine warranties.

Vacuum settings should be checked and adjusted to factory settings on a regular basis to ensure the best performance and reliability of our truck mounted carpet cleaning machine.

Author: Eric Jacobson, HydraMaster Engineering Team