Issue link: http://psai.uberflip.com/i/1293694
ASSOCIATIONINSIGHT Portable Sanitation Association International News BIWEEKLY EDITION SEPTEMBER 30, 2020 Page 8 Maintaining Pumps and Troubleshooting Issues…continued from page 4 • Make sure the secondary valve is drained daily. Some secondary valves are made of two pieces, and the bottom section can be easily removed to make sure the ball is free. • You can also try a gentle tap with a mallet on the secondary and possibly the top of the primary valve to make sure the float/ball is loose. It is not uncommon for a primary or secondary valve to become stuck if the tank is completely filled and then emptied. So even though the truck may be empty now, the floats can still be stuck from having done their job trying to protect the pump motor. • If you still have no vacuum, you may have more complex issues with a relief valve or the function of the pump motor. A call to the shop may be warranted. Safety • Objects under pressure are dangerous. Never attempt to remove or dislodge objects while under pressure. Always evacuate pressure before attempting to remove or dislodge an object from the hose or tank. Flying objects can act as projectiles and strike you or a bystander causing injury. • Know the pressure relief valve setting provided by the manufacturer (e.g., 10 psi). Pressurize the tank and watch the vacuum/pressure gauge. If pressure starts to exceed the manufacturer's maximum allowable limit for safety (e.g., 15 psi), stop immediately and contact the shop for next steps. They may need to contact the manufacturer for information on how to adjust the pressure relief valve. • Check the oil level of the vacuum pump before starting. Fill oil reservoir with recommended vacuum pump oil—see the vacuum pump operator's manual. • Position the vacuum pump lever to "VACUUM" as labeled on the pump. Start the engine and engage the PTO slowly. Run the engine up to the recommended RPMs. • WARNING—Truck engine RPM does not necessarily match the vacuum pump RPM. Improper engine speed can damage the pump and cause drive line failure. • Run until the recommended amount of vacuum is shown on the vacuum gauge before opening the fill valve. • Watch the fill indicator (sight glass, sight tube, or float lever indicator) to see when the tank is full. When full, close the "Fill" valve and shut down the vacuum pump by disengaging the PTO. If for any reason you can't visually see when the tank is full, you will be able to hear a sound change in the running pump signifying the primary shut-off has been activated. WARNING—DO NOT ALLOW THE PUMP TO RUN LONG IN THIS CONDITION. DOING SO WILL DAMAGE THE PUMP AND/OR REDUCE ITS LIFE. • WARNING—The capacity of the tank, when filled, may exceed the weight limitations of the truck chassis or the posted highway weight limits. It is the responsibility of the service technician to ensure s/he does not fill the tank that would exceed the weight limits allowed. Because pumping is such an integral part of portable sanitation, it makes sense to keep up with all maintenance requirements. Training is another key. Service technicians must understand how to safely operate and care for equipment so they are able to troubleshoot problems in the yard or on the route. And we all know that pump and pump truck maintenance costs much less than the expense of replacing a pump or pump truck! v