Data Sheet

Bulletin 71.1:MR105
7
INLET PRESSURE
OUTLET PRESSURE
ATMOSPHERIC PRESSURE
INTERMEDIATE PRESSURE
• Oil ows to large rotating equipment lubricating
bearings, e.g. turbines and compressors.
The loss of pressure or ow to the bearings or these
turbomachinery assets may shut down the equipment or
even the whole plant. Failure of the main pump or lter
results in the following upset operation:
• Auxiliary pump (Pump 2) and lter system is
brought into operation while main pump is
in operation.
• Auxiliary pump ramp up rate is one second.
• Auxiliary pump produces a pressure spike
that is beyond the limitations of the pressure
reducing regulator.
• The backpressure regulator relieves the excess
pressure back to the oil tank. Flow rate is 120% of
total pump rate.
Main pump can now be shut down to allow repair of
the system. High capacity direct-operated regulators
are recommended for this type of application where
speed of response is critical. The Type MR105 can
provide fast response to the pressure spikes as
described above while maintaining a constant delivery
pressure of oil to the bearing.
Wide-Open Monitoring System
Refer to Figure 4. Monitoring system provides
overpressure protection by containment and therefore
does not vent to the atmosphere. It involves a specic
arrangement of two regulators in series which are
congured such that if one regulator fails wide open,
the other regulator assumes control to maintain
the downstream pressure at a set limit. During an
overpressure situation, monitoring systems keep the
customer on line. Testing is also relatively easy. To
perform a periodic test on a monitoring regulator, increase
the outlet set pressure of the worker regulator and watch
the outlet pressure gauge to determine if the monitor
regulator takes over at the appropriate outlet pressure.
In such systems, both regulators are sensing downstream
pressure. During normal operation of a wide-open monitor
conguration, one regulator (worker) is set at the desired
downstream pressure. The other regulator (monitor) is set
at a higher pressure and remains wide open. The lock-up
pressure will be the worker regulator lock-up pressure.
If the worker regulator fails open, the monitor regulator
controls the downstream pressure at its setpoint and the
lock-up pressure will be the monitor lock-up pressure.
INLET PRESSURE
OUTLET PRESSURE
ATMOSPHERIC PRESSURE
INTERMEDIATE PRESSURE
SET HIGHER THAN
WORKER REGULATOR
WORKER CONTROL LINE
TYPE MR105
MONITOR REGULATOR
TYPE MR105
WORKER REGULATOR
Figure 4. Type MR105 Monitor Regulator Operational Schematic
MONITOR CONTROL LINE
M1203