Page 86 - Improving Machinery Reliability

58 Improving Muchinery Reliability

Table 2-1
Comparison of Governors for Mechanical-Drive Turbines

Mechanical/Hydraulic
Feature Electronic Governor Governor

cost At least two times base Base
Sensitivity Excellent Very satisfactory
Dependability Excellent. Malfunctions Excellent. Malfunctions
may develop with littlc or generally develop gradually.
no warning. Failsafe
devices are needed
Response to Excellent Excellent
load changes
Complexity Requires electronic engineer Will be understood by better
or first-class instrument- operators and mechanics
technician training
Maintenance By manufacturer’s By contract-maintenance
representative or resident specialist firms or
electronic engineer/ resident mechanics
instrument technician
Spare parts High, due to special Low. Standard product
investment nature of product available from affiliated
process plants if urgent
need should arise

156001 F[ 1114500]1
Toraue HorsePower

Torque ‘Simmonds Precision
tube gears
Figure 2-2. Typical installation schematic for phase-displacement-type torque meter.