Poor Pump Or System Performance - Agilent Technologies HS-16 Instruction Manual

Poor Pump or System Performance

Table 25 lists the faults, the probable causes and corrective actions to take if you have a problem with a large diffusion
pump.
Fault
Poor system pressure
Poor ultimate pressure
Slow pumpdown
Inlet pressure surges
High chamber
contamination of the
pump fluid
Pump will not start
High Throughput Diffusion Pumps
Table 25 Troubleshooting Guide
Probable Cause
Leaks in system, virtual or real
High process gas load
System dirty
Contaminated pump fluid
Low heat input
Inadequate cooling water flow
Cooling water is too cold
Cooling water flow is too high
High forepressure
Water in Quick Cool coil
Low heat input
Low fluid level
Malfunctioning pump assembly
Improperly located jets
Damaged jet system
Incorrect heater input
Fluid outgassing
Leak in system ahead of pump inlet
Forepressure too high
Prolonged operation in overload range
Cutting over from the backing pump too
early in the pump down cycle
Improper system operation and air
release procedures
Safety circuits or protective devices
prevent contactor from staying closed
Locate and repair
Measure gas load, eliminate cause
Clean system to reduce outgassing
Examine and clean pump; replace fluid
Check voltage. Check for continuity, burned-out
element, poor thermal contact
Check water pressure. Check tubing for obstructions
and backpressure
Check temperature
Adjust water flow
Check for leak in foreline, poor mechanical pump
performance, breakdown of mechanical pump fluid
Check and remove cause
Check heaters
Add fluid
Check and repair or replace
Check and correct
Condition fluid by operating the pump for a few hours
Check and correct
Check for leak in foreline, poor mechanical pump
performance, breakdown of pump fluid, and
incorrect valve operation
Adhere to operating procedures
Cut over at a lower chamber pressure
Adhere to operating procedures
Check utilities, flow devices switches, interlocks.
Check thermostat operation
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Corrective Action