Warewashing Basics

There are numerous variables to consider when selecting the right equipment for your dishwashing area:

Machine Ratings
A dishwasher’s rating is the number of full dish racks it can wash per hour, or, in the case of Rackless Conveyors, the number of dishes which can be washed per hour. The machine’s rating is essential in determining the type and size dishwasher that will be appropriate for your operation.

A dish rack is usually about 20” × 20” and can hold roughly 18 dinner plates or 25 to 36 glasses. Capacity will vary based on the size of the items being washed. Specially configured racks are available to accommodate bowls, flatware, etc.

Pumps and Motors
A warewasher’s pump and motor may be thought of as the machine’s heart and muscle. The pump is measured by its capacity in gallons per minute (GPM). The motor is rated by its horsepower (HP).
Together, the pump and motor work to provide adequate water volume and pressure to ensure proper cleaning and regulatory compliance.

Heating Equipment
Automatic warewashers contain water heaters that maintain the proper water temperature in the unit’s tank. These heaters use either electricity, steam or gas. As a general rule, heaters maintain a tank temperature of 160°F to ensure sanitation.

Hot water sanitizing warewashing machines use a booster heater to raise the incoming, general purpose hot water to at least 180°F for the final sanitizing rinse cycle.

Rinsing
The NSF requires an established amount of heat content to ensure sanitization. The water pressure for this cycle must be between 15 to 25 PSI. Most final rinse systems are controlled with an electric valve known as the “solenoid.” Water pressure is measured by a pressure gauge and regulated by a pressure reducing valve.