WorldWide Drilling Resource

63 WorldWide Drilling Resource ® APRIL 2015 Noisy Pump Part 1 by Bill Corey Pentair Water Training Institute It was late August, and I worked in Customer Service from May until August. I received a call from a woman who said her pump was making noise. I of course was expecting her to say it was a humming sound, but when I asked what the sound was she said, “It’s a banging sound, the whole house vibrates every time the pump turns on.” My thought was, this was not a pump problem, but a system problem. I asked which pump she had, and she answered it was a 1-hp (horsepower). I should have known she would not have the model number, so I didn’t get upset because she didn’t. But I did say we have several 1-hp pumps and asked if she knew the flow rate. Again she did not. Okay, so she can hear it every time it turns on. I asked what tank she had. Again, if she knew, she couldn’t tell me. So I said to turn the water on and let me know when the pump turned on and off. I had my watch and timed it. It was only 25 seconds. I said I wasn’t sure which pump she had, but I could tell the tank was too small. I told her she should have at least a one minute run time. I then asked if she knew who installed it. She said yes and gave me his name and asked if I needed his num- ber, but I said no since I knew him. I got her name and number so when I finished talking to him I could call her back. When I called him, we of course started out with some small talk as we hadn’t spoken for awhile. Finally, I got around to saying I had just spoken with Mrs. so and so. He said I better watch out because she was just trying to sue people. I said I would, and asked what pump he installed for her. He answered it was a 20P4E02H - a 20-gpm (gallons per minute), 1-hp, 230-volt pump. Then I asked how deep it was to water. He answered it was 20 feet. He said he didn’t ever want to talk to that woman again, and we hung up. I did my calculations and found he had 1½-inch pipe coming up from the well, but when he brought the water into the house he switched to 1-inch pipe. The flow rate at 115 feet to water with a 1-hp, 20-gpm pump was 26 gpm. Looking at the friction loss charts, I found 1-inch pipe at 26 gpm would have a velocity of 9.7 fps (feet per second) - very close to causing cavitation at an elbow, and would definitely cause pipes not connected to a stud to vibrate and bang up against them. Now I needed to decide the best way to stop this noise from happening. I’ll let you know what I determined to do, next month. Bill Bill Corey may be contacted via e-mail at michele@ worldwidedrillingresource.com --- *+ )#)('-()$* !(& )(%#'" +)""+ ,'.*,+ -'"/ 0 . 1 1 1 1