Gasboy Gilbarco Global Pumping Unit Operation Manual - Manual (Page 28)

Troubleshooting Troubleshooting Using Gauge Readings
Page 24 MDE-4447A Global Pumping Unit Operation and Service Manual · May 2008
Figure 5-3: Pressure Reading - Nozzle Closed
Troubleshooting Using Gauge Readings
The following examples help you determine the possible cause of a problem by observing the
gauge readings on the inlet (vacuum) and outlet (pressure) side of the pumping unit. Actual
readings may vary slightly, depending on installation and environmental conditions.
Figure 5-4: Gauge Troubleshooting 1
Symptoms: No Flow; Nozzle Open
Check Inlet Side
Probable Causes:
• Control Valve Stuck Shut
• Bypass Valve Open
• Atmospheric Float Valve Open
• Stuck Rotor Blades
• Broken Suction Line
• Strainer or Filter Completely
Plugged or in Backwards
• Empty Tank
At Control Valve
Cover At Strainer
(or Filter)
Cover