Are there any relevant acceptance standards for the vibration of WFB vertical self-priming pumps?

Damn it! When repairing this pump, attention must be paid to concentricity – concentricity is crucial, really important! ! ! I’ll say it three times: in the past, when we repaired this pump, we would fix the pump first and then install the motor; after lifting the shaft a little, we would lock it in place with three bolts. As a result, there was severe vibration, and two shafts would wear out in just one month. Later, I suggested that it couldn’t be repaired in that way; it was necessary to first connect the motor and pump assemblies, adjust the axial distance, and then use a dial indicator to check the radial position of the first-stage open impeller, ensuring that the error remained within 0.05. Once repaired, it should work properly for about a year. The difficulty lies in the force and angle when locking at 3 points. The manufacturer won’t tell you; if one shaft breaks, they’ll sell you another one at a higher price. We outsource the sewage pumping work; the pumps don’t have filters at their front end, and the collection tank is filled with oil vapor, so welding is not allowed. The secondary impellers get clogged frequently, which really drives us crazy. If there is significant vibration during inspection, then there are two possible reasons: either the concentricity is poor, or the verticality is poor.

Yes, and there are also foot screws, this contractor. . . They gave us expansion screws for the foundation; when I mentioned that, I was so pissed off – damn it, we in the maintenance team don’t have time to check such things. Those in charge of the equipment either don’t understand it or approve it after just taking a quick look. Sweep! It’s us who are affected

Isn’t this pump connected to the motor using a motor mount? There will still be deviations due to the fit between the flanges, and the precision of this machining is really poor

Haha, what kind of pump needs expansion bolts?:lol

Yes, the pump bracket is connected directly to the motor gland; the deviation is not due to issues with fitting precision – it’s a flaw in the design. The pump doesn’t have bearings; there is only one graphite bearing sleeve inside, which does not serve any purpose in fixing the shaft. In other words, if the pump shaft isn’t connected to the motor, it can move back and forth just like a car’s gear shift. At the connection point, the motor shaft is inserted into the pump shaft and then fixed using three set screws; these set screws are arranged at 120-degree angles to each other. The axial and radial orientation of the pump shaft depend entirely on these three set screws. Too low or too high an axis position will wear the pump body. If the pump is first installed in the motor and the three set screws are tightened directly, the machine won’t be able to rotate; therefore, the pump shaft needs to be lifted slightly before locking it in place. Even with new shafts and graphite bearing sleeves, there is still a gap, so an angle will appear when you lift the shaft. At this point, the motor shaft and the pump shaft are not on the same line, and then the shafts are doomed to fail. The correct method is what I mentioned above: first, connect the motor and pump assembly and ensure their concentricity. Then put them together in the pump casing. At first, no one paid attention to what I said; it wasn’t until the boss asked why the pump shaft kept giving errors that people started to listen to my installation method. At least a dozen shafts will have to be scrapped during that time.

These pumps are designed to require no maintenance for 3 to 5 years; if maintenance is needed within a year, there’s no need to choose such energy-intensive products.