Precautions for the initial startup of the hottest

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Precautions for initial startup of metering pump

1) Turn the dial counter clockwise to position 0 (at the minimum stroke of the pump), set the gauge to zero, reinstall and fix it, and then adjust the plunger stroke to the position of 30% - 40% of the maximum stroke

2). When starting for the first time, stop the pump for 20-30 seconds after the pump runs for 10-20 seconds, and repeat it for more than 10 times to fill the diaphragm oil chamber. During this operation, pay attention to whether there is abnormal noise from the motor or other moving parts, and eliminate the fault in time

3). Under zero pressure, the pump operates for about an hour, and then gradually increase the stroke, check the discharge pipeline flow, and preheat the base oil temperature

4). Set the flow regulation at 100% of the flow, gradually increase the pressure to the rated pressure, and operate for 30~60 minutes. Check the leakage at the packing seal of the plunger (the leakage should be controlled at 1/10000 of the flow, and 1 ml is about 15 drops) and the temperature rise of each moving pair (the lubricating oil temperature should not exceed 60 ℃ during long-term continuous operation)


the setting of the dial gauge should not exceed 100%, otherwise it is easy to have abnormal measurement and reduce the accuracy

keep the arm away from moving parts such as plunger and coupling to ensure personal safety

flow verification and calibration:

the metering pump has passed the performance test of clean water at normal temperature when leaving the factory, and the test results and flow calibration curve are listed in the certificate. After the first 12 hours of operation, the user should test and calibrate the pump, especially under the working condition that the physical properties of the medium are greatly different from that of clean water at room temperature, so as to obtain the accuracy of the pump flow under the specific operating state, and recalibrate the flow curve, so that the flow can be adjusted according to the retest curve during operation. Generally, it should be calibrated at 100%, 75%, 50%, 30% and 20% of the set flow, which is enough to see the performance of the pump within the whole regulation range. The verification method is as follows:

1) Measure the liquid level drop pumped in the calibrated container. This method can prevent the operator from contacting harmful liquids

2). Collect and measure the liquid at the pump outlet, which can be calibrated by weighing method or volumetric method

during calibration, there must be pressure at the discharge port of the pump, otherwise the pump cannot work normally

initial adjustment of packing:

turn the packing nut. If necessary, tap the thread gently to make the packing in a compressed state, and then turn it for half a turn. If the temperature at the packing rises, loosen the packing nut (1/6 turn each time, with an interval of 5 minutes) to prevent damage to the packing

note: micro leakage at the sealing cover is allowed, and it has the function of cooling and lubricating the packing and its plunger, which can greatly prolong the service life of both. For the replacement and operation method of packing, see the initial adjustment of

adjustment gauge:

1) According to the needs of the process flow, check the flow calibration curve after the retest, get the corresponding stroke percentage value, rotate the pointer of the gauge to the specified position, and then lock the locknut behind the adjusting turntable to maintain the set flow

2). When rotating the gauge, it should not be too fast or too fierce, and it should be adjusted from small flow to large flow; If it is necessary to reduce the flow, the adjusting gauge should be turned to the small direction with more spins, and then to the large flow direction to the required scale, so as to eliminate the vacancy error

3). The stroke adjustment of the pump can be carried out during shutdown or operation. After stroke adjustment, the flow of the pump can be stabilized for about 1-2 minutes; The greater the change of stroke length, the longer the time it takes for the flow to stabilize, especially for the diaphragm pump

adjustment of oil makeup valve group:

1) Adjustment of the safety automatic oil replenishment valve group:

the diaphragm oil chamber of the diaphragm pump is filled with transformer oil when leaving the factory, and the user does not need to disassemble or refill

but when there is no oil in the oil chamber or the oil quantity is insufficient, please follow the following method:

a) Adjust the pump stroke to 40~50%, open the oil storage tank cover of the safety valve, gently press the oil replenishing valve rod by hand to inject oil into the diaphragm oil cavity, and at the same time, turn the coupling to make the diaphragm agitate and discharge the gas in the diaphragm cavity until the bubbles no longer rise

b). When driving, loosen the adjusting screw of the safety valve gradually until it takes off. As the pump can not only reduce the weight of the structural parts significantly and improve the reliability of the service process, the gas in the oil chamber will be discharged, and it should take off several times. When the pressure generated in the pump reaches the working pressure, the oil in the oil chamber should not overflow from the safety valve; When the pressure generated in the pump reaches 1.1~1.3 times of the working pressure (the maximum discharge pressure should be within 1MPa), the safety valve should be opened quickly to make the pressure in the pump no longer rise. At this time, lock the locknut on the adjusting bolt of the safety valve, and the adjustment of the safety valve is completed

c). While the safety valve takes off and exhausts, it makes short-term oil replenishment during the plunger suction movement. If the oil is replenished too much, it will produce vibration and impact sound. When the plunger is scheduled, gently press the oil replenishment valve rod to discharge the excess oil until the pump runs smoothly

d). The opening pressure of the automatic oil makeup valve is 0.8 atmospheric pressure. Put your finger gently and drag the load collet on the oil replenishing valve rod with a high-precision gear reduction electronic speed regulating motor. With the movement of the plunger, you can obviously feel the up and down vibration, indicating that the spring pressure of the oil replenishing valve is appropriate

2). Air release and safety valve adjustment of limit oil makeup valve:

limit valve and one-way oil makeup valve have been basically adjusted at the factory, especially when used in wet construction environment. Users should try not to move

a). When bleeding, first remove the safety valve on the upper part of the hydraulic cylinder as a whole, fill oil into the oil cavity from the connecting hole, and at the same time, turn the coupling to make the diaphragm agitate, and discharge the gas in the membrane cavity until it no longer bubbles upward. Fill up the oil and then reinstall the safety valve

b). When starting up, loosen the adjusting screw of the safety valve gradually until it takes off. With the discharge movement of the pump, discharge the gas in the oil chamber, and take off several times. When the pressure in the pump reaches the working pressure, the oil in the oil chamber will no longer overflow a large amount from the safety valve, and its adjustment is basically in place, which can lock the locknut of the safety valve. At this time, slight leakage of the safety valve is allowed, which can play the role of exhaust, and its oil volume is replenished by the one-way oil makeup valve at any time

remote and automatic control of flow:

the top of this series of pump regulation box can be set with electric control or pneumatic stroke regulation device, and the frequency converter can also be used to adjust the motor frequency, so as to change the pump speed and adjust the flow. Please refer to the operation manual of the corresponding automatic control device for specific operation

diaphragm rupture alarm device:

according to the different structure and principle, it is divided into chemosensitivity (BH type) and pressure-sensitive (by type). Chemical sensitive alarm is to use the conductivity difference between hydraulic oil or intermediate medium and transmission medium to realize diaphragm rupture alarm; Pressure sensitive is to realize diaphragm rupture alarm by transferring pressure changes between two diaphragms. See the operating instructions of diaphragm alarm for specific installation, connection and operation methods. (end)

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