3.4.5
Maintaining Bulk Plant Pumps,
Strainers and Bypass Systems
Knowing how to maintain bulk plant pumps, strainers and
bypass systems is necessary for a safe and efficient plant
operation.
In this module you will learn to identify:
(1) Types of propane pumps
(2) Pump maintenance techniques
(3) The function of strainers and strainer maintenance
procedures
(4) Pump protective devices and applicable maintenance
techniques
3.4.5 Student Book  © 2004 Propane Education & Research Council
Page 1
Identifying the Types of Propane Pumps
Two types of pumps used for transferring propane are:
•
Regenerative turbine
•
Positive displacement
Regenerative Turbine Pumps
Figure 1. Regenerative
Turbine Pump
Courtesy of Corken Pump Co.
3.4.5 Student Book  © 2004 Propane Education & Research Council
Page 1
Identifying the Types of Propane Pumps
Regenerative Turbine Pumps
Courtesy of Corken Pump Co.
Figure 1. Regenerative Turbine Pump
3.4.5 Student Book  © 2004 Propane Education & Research Council
Page 2
Identifying the Types of Propane Pumps
Regenerative Turbine Pumps— Regenerative turbine pumps are
used at cylinder docks, dispensing stations, and in other applications that
require capacities of up to 25 gallons per minute.
Courtesy of Corken Pump Co.
Figure 1. Regenerative Turbine Pump
3.4.5 Student Book  © 2004 Propane Education & Research Council
Page 2
Identifying the Types of Propane Pumps
Sliding Vane Pumps
At the pump inlet, the distance
between the rotor and the pump
liner widens and centrifugal
force propels the vanes out
from the center of the rotor.
As the rotor continues rotating
toward the outlet, the oval
shape of the liner results in less
space between the rotor and
the liner wall, acting to
compress the liquid and
increase its pressure at the
pump’s outlet.
Courtesy of Corken Pump Co.
Figure 2. Sliding Vane Pump
3.4.5 Student Book  © 2004 Propane Education & Research Council
Page 3
Identifying the Types of Propane Pumps
Sliding Vane Pumps
Courtesy of Dover Corp., Blackmer Pump Div.
Figure 3a. Operation of Sliding Vane Pump
3.4.5 Student Book  © 2004 Propane Education & Research Council
Page 4
Identifying the Types of Propane Pumps
Sliding Vane Pumps
Courtesy of Blackmer Pump Div.
Figure 3b. Detail Of How Sliding Vanes Are Actuated
3.4.5 Student Book  © 2004 Propane Education & Research Council
Page 4
Identifying the Types of Propane Pumps
Gear Pumps
Courtesy of Blackmer Pump Div.
Figure 4. Gear Pump
3.4.5 Student Book  © 2004 Propane Education & Research Council
Page 5
Identifying Pump Maintenance Techniques
NFPA 58 requires that qualified persons must operate & maintain bulk plants and industrial installations in accordance with the
company’s written operating and maintenance procedures.
C om pan y
O & M
P ro ced u res
Before starting any bulk plant or industrial installation maintenance procedure, be sure to review your company’s maintenance
procedures and equipment manufacturer’s instructions.
Lubrication
Vane and gear-type pump bearings should be
lubricated every three (3) months with a light Number
2 Lithium-base type of grease. Apply grease slowly
with a hand gun to the grease fittings on each bearing
cover until excess grease begins to come from the
relief fittings. Do not use a high-pressure grease gun,
and stop applying new grease when excess grease
appears.
3.4.5 Student Book  © 2004 Propane Education & Research Council
Page 6
Identifying Pump Maintenance Techniques
Drive
Components

Belt-driven pumps should be examined for
proper alignment and condition of the drive belts when
lubrication is scheduled.
Shaft coupling-driven
pumps should be
checked for proper alignment of the couplings and wear
of the spacing bushings.
Gear Reduction driven pumps must be
checked for proper alignment and wear of their universal
joints or couplings as applicable. The gearbox and Ujoints should be lubricated according to manufacturer
instructions and maintenance recommendations.
3.4.5 Student Book  © 2004 Propane Education & Research Council
Page 6
Identifying Pump Maintenance Techniques
At all times during the maintenance of pumps and their drive
components, electrical controls should be locked out and
tagged according to company procedures.
If the drive belt and pulley guards or coupling guards are
removed during inspection or maintenance operations, they
must be properly installed and secured before lock out and
tag out devices are removed and the equipment is placed
back into service.
3.4.5 Student Book  © 2004 Propane Education & Research Council
Page 7
Strainers and Strainer Maintenance Procedures
Every pump should have a strainer in the inlet piping to protect it against
damage from foreign matter in the propane supply.
Courtesy of Smith Precision Products
Figure 5. Propane Strainer
3.4.5 Student Book  © 2004 Propane Education & Research Council
Page 7
Strainers and Strainer Maintenance Procedures
Selecting and Sizing Strainers
•
Most manufacturers recommend that the installed strainer be at least one
pipe size larger than the inlet piping.
•
They also recommend a strainer with as large a screen area as possible,
and to locate it at least ten pipe diameters upstream from the pump inlet,
whenever possible.
Strainer Maintenance
•
The strainer must be isolated from the rest of the transfer system by
closing liquid piping valves upstream and downstream of the strainer.
•
Propane trapped in the strainer must be bled off safely.
•
The cover must be removed from the bottom of the strainer body or
casing and be cleaned using a brass bristle brush and a solvent if
necessary.
3.4.5 Student Book  © 2004 Propane Education & Research Council
Page 8
Other Pump Protective Devices
Flexible Connectors— Pumps are usually connected to the inlet and outlet
piping with flexible connectors to avoid serious damage from vibration, expansion
and contraction of the piping with heat and cold, and sags or other forces
transmitted to the pump through the plant transfer piping.
Figure 6. Flexible Connector
3.4.5 Student Book  © 2004 Propane Education & Research Council
Page
9
Other Pump Protective Devices
Hydrostatic Relief Valves — Protection against hydrostatic pressure
damage is provided using hydrostatic relief valves.
Figure 7. Hydrostatic Relief Valve
Courtesy of Sherwood Corp
3.4.5 Student Book  © 2004 Propane Education & Research Council
Page
11
Other Pump Protective Devices
Selecting and Maintaining Hydrostatic Relief Valves —
Hydrostatic relief valves must be designed to open at a pressure of not less than
400 psig and not more than 500 psig when selecting new or replacement valves.
Figure 8. Hydrostatic Relief
Valves With Rain Caps
Hydrostatic relief valves should be fitted with rain caps to prevent moisture
and debris from accumulating inside the valve.
3.4.5 Student Book  © 2004 Propane Education & Research Council
Page
12
Other Pump Protective Devices
Pump Internal Relief Valves
Figure 9. Internal Relief Valve
3.4.5 Student Book  © 2004 Propane Education & Research Council
Page
13
Other Pump Protective Devices
Manual and Automatic Bypass Circuits
Figure 9. Internal Relief Valve
3.4.5 Student Book  © 2004 Propane Education & Research Council
Page
14
Other Pump Protective Devices
Manual and Automatic Bypass Circuits
Figure 11. Automatic Bypass Valve
3.4.5 Student Book  © 2004 Propane Education & Research Council
Page
15
Other Pump Protective Devices
Maintaining Automatic Bypass Valves
The bypass valve should be set at least 15 to 20 psi below the
pump’s internal relief valve setting. Qualified personnel using
properly selected liquid-filled pressure gauges (rated for 0-400 psig
service) can adjust the valve’s opening setting if the automatic
bypass is not opening at the proper pressure to protect the pump.
To determine the automatic bypass opening setting or to adjust the
setting, follow your company’s written maintenance procedures and
equipment manufacturer instructions.
3.4.5 Student Book  © 2004 Propane Education & Research Council
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16
Time to See If You Got the Key Points of
This Module…
• Complete the Review on pages 18 & 19.
• See if you are ready for the Certification
Exam by checking off the
performance criteria on page 20.
3.4.5 Student Book  © 2004 Propane Education & Research Council
Pages 18 - 20