3.4.5

1. 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: • Types of propane pumps • Pump maintenance techniques • The function of strainers and strainer maintenance procedures • Pump protective devices and applicable maintenance techniques

2. 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. Identifying the Types of Propane Pumps Regenerative Turbine Pumps Courtesy of Corken Pump Co. Figure 1. Regenerative Turbine Pump

4. Courtesy of Corken Pump Co. Figure 1. Regenerative Turbine Pump 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.

5. Courtesy of Corken Pump Co. Figure 2. Sliding Vane Pump 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.

6. Identifying the Types of Propane Pumps Sliding Vane Pumps Courtesy of Dover Corp., Blackmer Pump Div. Figure 3a. Operation of Sliding Vane Pump

7. Identifying the Types of Propane Pumps Sliding Vane Pumps Courtesy of Blackmer Pump Div. Figure 3b. Detail Of How Sliding Vanes Are Actuated

8. Identifying the Types of Propane Pumps Gear Pumps Courtesy of Blackmer Pump Div. Figure 4. Gear Pump

9. Identifying Pump Maintenance Techniques NFPA 58 requires that qualified persons must operate & main-tain bulk plants and industrial installations in accordance with the company’s written operating and maintenance procedures. Before starting any bulk plant or industrial installation mainten-ance procedure, be sure to review your company’s maintenance procedures and equipment manufacturer’s instructions.

10. Identifying Pump Maintenance Techniques

11. 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.

12. 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

13. Selecting and Sizing Strainers Strainer Maintenance • 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. • 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. Strainers and Strainer Maintenance Procedures

14. 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

15. 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

16. 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.

17. Other Pump Protective Devices Pump Internal Relief Valves Figure 9. Internal Relief Valve

18. Other Pump Protective Devices Manual and Automatic Bypass Circuits Figure 9. Internal Relief Valve

19. Other Pump Protective Devices Manual and Automatic Bypass Circuits Figure 11. Automatic Bypass Valve

20. 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.

21. 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.