Pneumatically operated tables and lifts require air bag pressure control that is accurate and repeatable. These tables and lifts require less maintenance than conventional hydraulic lift tables, since there is no fluid to leak and contaminate processed goods.

In this application, a QB1 with a PSR volume booster is used to inflate air bags to raise and lower a work table. Since the limit switch controls the height, change in weight on the table does not affect the height. Single loop control works great in this application because the response time is dampened just enough to compensate for back pressure and prevent oscillation.

Proportion-Air products can be used to control a single air bag or multiple air bags with the same device. Often, a foot pedal or hand control is used to provide a command signal to our device to tell us to fill (raise) or exhaust (lower) pressure, as needed.