The mesh size of the filter was too high, about 120 mesh (Figure 1). The next day, I assisted the power construction and installation team to remove the filter element of 120 mesh and change it to 40 mesh (Figure 2)
Export line bypass to the deaerator, bypass piping design is too large (DN80, below 1/2 black arrow pointing to bypass), also temporarily not installed the throttling orifice plate, lead to export the bypass flow is too large, when using small throttle control flow, flow through the valve noise is very big, owners worry has impact to the valve, causing premature valve wear and tear, As a result, the pump could not be arranged to run continuously for 4 hours through the bypass, running for about 10 minutes, gradually accelerating from 25Hz to 40Hz (Figure 3 shows the inlet and outlet pressure at 35Hz speed). After checking the outlet pressure and pump vibration (less than 1mm/s, far below the standard of 4.5mm/s), the pump was normally used to refill the boiler the next day after communicating with the owner and customer.
The oil level gauge of the water pump and the positioning screw on the bearing box are not suitable to be installed outdoors where there is a possibility of rain and water seepage. Please install rain shielding facilities above the bearing room. (The black cable tie in Figure 1 is only to demonstrate that the exhaust hole is open to the top). Some of the oil level meters have been flooded, have been drained, refuel. (Figure 2 shows the water below the oil level)