Upper Plumbing Train

Gauges are located on the Upper Plumbing on top of the Dryer.

Inlet Pressure Gauge: This Gauge near the fuel inlet connection point (on either LP or natural gas) gives the supply line pressure at the inlet for service and operating reference. It is used to evaluate the fuel supply adequacy or possible line restrictions.

Burner Pressure Gauge: The pressure on the Burner manifold pipe, downstream of all controls, which measures Burner gas pressure (LP or NAT). There is no “correct” setting for this. The pressure will vary until the proper air drying temperature is established.

Modulating Motor and Butterfly Valve

The Modulating Motor is a self-contained device with a transformer for stepping down 120V Control Voltage to 24V to power the motor. It is controlled by a set of contact closure signals from the I/O Panel (discussed in the Controller Installation Manual). The Modulating Motor develops 150 in-lb. of torque and rotates 160 degrees to open and close a butterfly Modulating Valve through a linkage system that prevents the Modulating Valve from rotating beyond the maximum of 90 degrees full open rotation.

The Valve linkage has been factory- adjusted so that the valve is closed when the Motor is in its full counterclockwise position, which will be the case any time the burner is turned OFF. The Modulating Valve is a butterfly-type control valve, which is moved by linkage from the Modulating Motor. Should the Modulating Motor or Valve be replaced, the linkage should be set in accordance with picture at right.

As a temporary measure, the Burner can be manually adjusted in the event of a defective Modulating Motor by removing the linkage arm and running the Modulating Valve by hand and manually setting fuel flow to the Burner.

Plenum Static  Air Pressure Line

Modulating Motor and Butterfly Valve