Page 156 - Improving Machinery Reliability

128 Improving Machinery Reliability

c. Coolers and filters:
1. Fabrication drawings
2. Priced spare parts list and recommendations
3. Completed data form for cooler(s)
d. Instrumentation:
1. Controllers
2. Switches
3. Control valves
4. Gauges
Pumps and drivers are reviewed for accessibility, coupling arrangements,
baseplate mounting method, proximity of discharge and suction pipe, etc.
Motive gas suppliers are given applicable scrutiny.
Overhead tank, main reservoir, and drain tanks (degassing tank, sour seal
oil reservoir) must comply with specifications. Should overhead tanks be
given thermal insulation?
Coolers must be suitable for heating the seal oil during oil flushing opera-
tions. Are they sized to cool the oil flow resulting from more than one pump
operation? Can filters be fully drained? Do they have vent provisions? What is
their collapsing pressure? What kind of cartridges do they accept? Specifica-
tion compliance must be ascertained.
Is instrumentation accessible? Can it be checked, calibrated, or replaced
without causing a shutdown? Is it properly identified? Are controllers and
transmitters located at optimum locations for rapid sensing and control? Are
switches of sound design and are they manufactured by a reputable company?
Control valves sized right? Gauges made of acceptable metallurgy? Proper
ranges?
11. Lube oil schematic, including:
a. Steady-state and transient oil flows and pressures
b. Control, alarm, and trip settings
c. Heat loads
d. Utility requirements including electrical, water, air, steam, and nitrogen
e. Pipe and valve sizes
f. Bill of materials
Are steady-state and transient flows within capability of pumps and accu-
mulator? Will pumps and accumulators satisfy turbine hydraulic transients?
Accumulator maintainable?
Are control, alarm, and trip settings tabulated?
Do heat loads have to be accommodated by fouled coolers?
Utility requirements are needed to allow plant design to proceed in such
areas as electrical protective devices, water supply lines, and nitrogen supply
for blanketing of reservoir. Steam requirements must be identified for turbine-
driven pumps.
Pipe and valve sizes need to be checked to determine acceptable flow velocity.
The bill of materials should be reviewed to identify both inexpensive and
hard-to-obtain components. It should be reviewed also by maintenance per-
sonnel. Are O-rings, rolling element bearings, etc., identified so as to allow
purchase from the actual manufacturers of these components?