Check valve cause of vertical pump high noise and vibration
KSB SPFC 150-430A 水泵运行有异响
Abnormal noise of water pump operation
SPFC 150-430A 现场位号：#4
After arriving at the site, ask the owner to start the pump, and the test noise value is 84dB, as shown below (the surrounding environment is quiet). Vibration value The vibration of the motor base is 3.0mm/s(axial and radial direction), the vibration of the pump bearing box is 6.3mm/s(axial and radial direction), and the vibration of the motor driving end is 8.5mm/s(radial direction).
Check pump and motor couplings, axial and radial alignment meet the requirements. Pump manual turning, very flexible, no stuck phenomenon.
When the #4 pump is stopped, the #3 pump next to it is started. The noise value of #3 is 74dB, and the vibration is within 4.5mm/s. It is strange that the vibration is strong when touching the bearing chamber of #4 pump by hand. The measured vibration value is 5.7mm/s (Figure 1 below). Shut down pump #3 and eliminate the vibration of pump #4. Similarly, when the #2 pump, which is slightly away from #4, is started, the vibration value of the bearing chamber of #4 pump, which is shut down, is actually 2.6mm/s (Figure 2 below).
The field distribution photos of four vertical pumps are as follows, and the white is the check valve:
Cause analysis of pump noise and vibration:
No. 4 pump outlet check valve, there is a situation of lax closure, when #4 stop, next to #3 pump, #2 pump started, #4 pump outlet pipeline reflux situation.
When No. 4 pump is run alone, the water is not unobstructed due to the outlet valve. Therefore, the noise and vibration of the pump group are large.
Please check whether the No. 4 outlet pipeline check valve has any foreign body stuck, or the valve is worn or faulty.