ITT Goulds Pumps XHD, Installation, Operation And Maintenance Manual

Page: 46 / 160

Commissioning, Startup, Operation, and Shutdown
XHD Installation, Operation, and Maintenance Manual 44
WARNING:
• The pump should be run for a period of 15 minutes to verify the impeller is properly
tightened onto the shaft. In addition to verifying the impeller is properly tightened, it is
necessary to verify that the bearing frame adjustment plate bolts (352G) and nuts (427D)
are properly secured and tight. Failure to check that the impeller is tight and the bearing
frame adjustment plate bolts and nuts are properly tightened can result in the rotating
element shifting during operation.
Figure 26: Securing the bearing frame adjustment plate
• Risk of mechanical seal damage leading to breach of containment. If a cartridge
mechanical seal is used, ensure that the set screws in the seal locking ring are loosened
and that the centering clips have been installed prior to clearance adjustment.
The front clearance is set at .51 mm (0.020 in) at the factory but could change due to piping
attachment during installation. A change in pump performance may be noted over time by a
drop in head or flow or an increase in power required.
Table 5: Impeller clearance methods
The XHD and XHD Value Option models have different methods of setting the impeller clearance.
Pump Model Method
XHD The impeller clearance is set by measuring the gap between the rear shroud of the
impeller and the casing volute liner, and measuring the gap between the front of the
impeller and the suction seal ring clearance.
Skip to the "Set Impeller to Suction seal Ring Clearance Dial Dial Indicator Method -
XHD" step.
After impeller rear clearance has been set on the XHD, the suction seal ring
clearance must also be set.
XHD Value Option The impeller clearance is set by measuring the gap between the front of the impeller
and the suction side liner. Use the "Set the impeller clearance dial indicator method
- XHD Value Option" step. All units that do not have the Adjustable Suction Seal
Ring as part of the assembly are set via this method.