How is the pump filled after its maintenance? ?

Can the inlet valve be opened directly to fill the pump after maintenance? ? Should we still use a pre-heater? First, perform a water flushing test and pressure test on the pump after maintenance ； Secondly, the purging process is also a process of preheating the pump; during this process, it is particularly important to prevent condensed water from remaining inside the pump after the steam purging is completed ； Third, after the purging and preheating are complete, all residual pressure and water inside the pump chamber must be completely removed ； Fourth, check whether the oil return line of the slurry pump and the pre-heating line are being operated as required (the valves at the inlet and outlet of the pre-heating line should be closed, and the oil return line should be open) ； Fifth, slowly open the outlet valve, while monitoring the outlet pressure and flow rate of the slurry pump to prevent excessive flow that could cause short-term fluctuations or result in the slurry pump running dry ； Sixth, the slurry introduced into the pump body of the slurry pump is sent back to the dirty oil tank via the return line, or to the heavy dirty oil line. It is important to control the preheating rate at 50 degrees per hour, until the temperature of the pump body matches that of the slurry being pumped. Once this is achieved, the valve on the return line should be closed, the inlet valve opened, while the outlet valve remains closed. Finally, the valve on the preheating line should be opened slowly. This ensures it is ready for use in good condition.

The inlet valve also needs to be opened even when using a pre-heater. .

May I ask, after the pre-heating line is activated, is the gas from the pump body discharged into the inlet pipeline? Could that cause the pump to run dry?

What is the temperature difference? After steam flushing, there is no need to seal with oil or expel water for preheating; once a certain temperature is reached, the temperature difference is reduced, and then preheating is carried out using a preheating line and an oil removal line

Is it not necessary to inject sealing oil during preheating? ?

Some units are not designed with oil sealing, while others do; operations must be carried out according to the differences in the design of each unit.

3.2. Operation of the slurry pump 3.2.1. Preparations before starting the pump? 3.2.1.1 Add an appropriate amount of qualified lubricating oil that has undergone three-stage filtration (special bearing oil for imports), or enable mist lubrication; turn on the cooling water for the cooler, and check that the drainage from the drain pipe at the pump base is normal. ? 3.2.1.2. Allow an appropriate amount of cooling steam to flow through the bellows seal. ? 3.2.1.3. Open the seal oil in an appropriate amount. ? 3.2.2. Preheating. ? 3.2.2.1. Open the pump inlet, open the upper and lower preheating valves of the pump casing, then slightly open the pump outlet for preheating, gradually raising the temperature of the pump body; the heating rate should not exceed 50°C/h, with the temperature at the pump outlet serving as the monitoring point. ? 3.2.2.2. During the temperature-raising phase after pumping in the hot medium, the pump should be rotated periodically, once every half hour, two full rotations each time. While rotating it, check for any blockages or abnormal noises inside. Once it has been preheated to the operating temperature, contact a blacksmith to inspect the center of the pump; once no abnormalities are found, it can be put into use. 3.2.3. Pump startup? 3.2.3.1. Close the preheating lower valve of the pump, and set the preheating upper valve of the pump to the open position. ? 3.2.3.2. After the barring test shows no abnormalities, start the motor and open the outlet valve to the level required for operation. ? 3.2.4. Shutdown of the pump? 3.2.4.1. Shutting down the pump for standby: Slowly close the pump’s outlet valve, stop the motor, keep the pump in a preheated state, and turn the pump shaft as required. ? 3.2.4.2. Pump shutdown for repair: Close the pump outlet valve, stop the motor, allow it to cool naturally to 100°C, then cut off the cooling steam and cooling water for the waveguide; during the cooling process, rotate the pump shaft as specified.