离心泵的启动、运行和停止三个过程对于设备本身和整个工作流程的正常运转来说都是至关重要的。

接下来杭州振兴工业泵制造有限公司梳理一下常见的泵启停操作步骤以及运转中需要注意的事项：

泵启动前的准备工作

1、灌泵

除了液下泵，其它泵启动前（自吸泵靠前次启动）都要进行灌泵（即要求泵送介质必须充满泵腔体）。

2、倒灌装置灌泵：

打开入口管线的截止阀，打开所有的排气管路，排放气体，缓慢的转动转子，当泵送介质没有气泡时关闭排气阀。

3、吸入装置灌泵：

打开入口管线的截止阀，打开所有的排气管路，排放气体，向泵灌注（吸入管必须设底阀），缓慢的转动转子，当泵送介质没有气泡时，关闭排气阀。

4、打开所有的辅助系统，并要求所有的辅助系统至少工作10分钟以上，等到整个辅助系统工作稳定后，方可进行下一步，此处辅助系统包括润滑油系统、密封冲洗系统、冷却保温系统等。

5、对设备进行盘车检查设备转动是否灵活：

启动电动机，再次判断泵旋转方向是否正确；确认后固定好联轴器护罩。

6、干气密封系统投用：

打开氮气入口阀，对密封腔进行充压。干气密封的气源压力必须在0.5～1.0Mpa之间。每台泵按具体要求对密封腔压力、流量进行调整。

泵的启动

1、确认吸入阀全开，排出阀关闭或微开；有小流量管路时，排出阀全关，全开小流量阀。

2、关闭出口管路截止阀（必须保证小流量）；

3、启动电机，使泵转子达到运转速度；

4、缓慢打开出口阀使泵的出口压力、流量达到规定数值。开出口阀同时应检查电机电流变化，避免电机过载。在流量增加时，还应注意泵的密封有无异常泄漏、泵的振动情况是否正常、泵体和电机等有无异常声音、出口压力的变化等，如泵有异常的泄漏、异常的振动、异常的噪音或出口压力低于设计值，应查明原因并进行处理。

5、当泵正常运转后，检查泵的出口压力、出口流量、电机电流、轴承和密封处的温度、润滑油的油位、泵的振动、噪音以及密封处泄漏情况；（根据工艺需要）关闭小流量旁路的阀门。做好相关设备运行记录。

注意：

( 1 )泵的大启动频率不能超过12次/小时；

( 2 ) 压差不能低于设计点，也不能在系统中引起性能参数的波动。泵出口压力表值等于压差加上入口压力表值；

( 3 ) 满负荷时电流表上的读数，保证电流不超过电机铭牌上的值；

( 4 ) 泵配套的电机有可能根据买方的要求，按实际介质比重选择，在进行试运行时，应考虑电机的功率。如果实际介质比重比试运行介质的比重小，请在试运行时，严格控制阀门的开度，避免电机过载甚至烧毁。必要时必须与泵制造商联系。

泵的停机

1、慢慢关小排出阀，直到流量达到小流量为止。

2 、切断电源，停泵，关闭出口阀。

3、设有小流量旁通管路时，在旁通阀全开的情况下关闭排出阀，然后切断电源停泵。高温泵要在降温到80℃以下时才可停止循环水；密封系统（冲洗液、密封气）要在停泵20分钟以后视情况停止。

4、备用泵：吸入阀全开，排出阀全关（设有小流量旁通管路时，旁通阀全开，排出阀全闭），从而使泵内处于满液的吸入压力状态。备用泵的冷却水要继续投用，保持润滑油液位不低于规定油位。冬季要特别注意检查，保持冷却水畅通，避免冻凝。

5、备用泵要按规定盘车。

6、 (停车后)需要检修的泵，停泵（降温）后先关闭干气密封系统氮气入口阀，将密封腔泄压，再完全排出泵内液体和冷却系统中的冷却水，使泵体内的压力下降为零，泵内残存的物料吹扫干净，所有阀门全部关闭，并且与变电所联系断电。现场处理要满足HSE要求。

The three processes of start, operation and stop of centrifugal pump are very important for the normal operation of the equipment and the whole working process.

Next, Hangzhou Zhenxing Industrial Pump Manufacturing Co., Ltd. combs the following common pump start and stop operation steps and matters needing attention during operation:

Preparation before starting the pump

1. Irrigation pump

In addition to the submerged pump, other pumps must be filled before starting (the first start of the self-priming pump) (that is, the pumped medium must be filled into the pump chamber).

2. Pump filling of reverse filling device:

Open the stop valve of the inlet pipeline, open all the exhaust pipelines, discharge the gas, slowly rotate the rotor, and close the exhaust valve when there is no bubble in the pumped medium.

3. Filling pump of suction device:

Open the stop valve of the inlet pipeline, open all the exhaust pipelines, discharge the gas, fill the pump (the suction pipe must be equipped with a bottom valve), slowly rotate the rotor, and close the exhaust valve when there is no bubble in the pumped medium.

4. Open all auxiliary systems, and require all auxiliary systems to work for at least 10 minutes. When the whole auxiliary system works stably, the next step can be carried out. Here, the auxiliary system includes lubricating oil system, seal flushing system, cooling and heat preservation system, etc.

5. Turn the equipment to check whether it can rotate flexibly:

Start the motor, judge whether the rotation direction of the pump is correct again; fix the coupling guard after confirmation.

6. Operation of dry gas sealing system:

Open the nitrogen inlet valve to charge the sealing chamber. The air source pressure of dry gas seal must be between 0.5 and 1.0MPa. Each pump shall adjust the pressure and flow of the sealing chamber according to the specific requirements.

Pump start-up

1. Confirm that the suction valve is fully open and the discharge valve is closed or slightly open; when there is a minimum flow pipeline, the discharge valve is fully closed and the minimum flow valve is fully open.

2. Close the outlet pipeline stop valve (the minimum flow must be guaranteed);

3. Start the motor to make the pump rotor reach the running speed;

4. Slowly open the outlet valve to make the outlet pressure and flow of the pump reach the specified value. Open the outlet valve and check the motor current change to avoid motor overload. When the flow rate increases, it is also necessary to pay attention to whether the seal of the pump has abnormal leakage, whether the vibration of the pump is normal, whether the pump body and motor have abnormal sound, and whether the outlet pressure changes, etc. if the pump has abnormal leakage, abnormal vibration, abnormal noise or the outlet pressure is lower than the design value, the cause shall be found out and handled.

5. When the pump is in normal operation, check the outlet pressure, outlet flow, motor current, temperature of bearing and seal, oil level of lubricating oil, vibration, noise of pump and leakage of seal; (according to process requirements) close the valve of minimum flow bypass. Make operation records of relevant equipment.

Be careful:

(1) the maximum starting frequency of the pump shall not exceed 12 times / hour;

(2) the pressure difference shall not be lower than the design point or cause the fluctuation of performance parameters in the system. The pump outlet pressure gauge value is equal to the pressure difference plus the inlet pressure gauge value;

(3) the reading on the ammeter at full load to ensure that the current does not exceed the value on the motor nameplate;

(4) the matching motor of the pump may be selected according to the requirements of the buyer and the specific gravity of the actual medium, and the power of the motor shall be considered during the trial operation. If the specific gravity of the actual medium is smaller than that of the commissioning medium, please strictly control the opening of the valve during the commissioning to avoid overloading or even burning the motor. The pump manufacturer must be contacted if necessary.

Pump shutdown

1. Slowly close the discharge valve until the flow reaches the minimum flow.

2. Cut off the power supply, stop the pump and close the outlet valve.

3. When the minimum flow bypass pipeline is set, close the discharge valve when the bypass valve is fully open, and then cut off the power supply to stop the pump. The circulating water can only be stopped when the temperature of high-temperature pump drops below 80 ℃; the sealing system (flushing fluid and sealing gas) shall be stopped as the case may be 20 minutes after the pump is stopped.

4. Standby pump: the suction valve is fully open and the discharge valve is fully closed (when the minimum flow bypass pipeline is set, the bypass valve is fully open and the discharge valve is fully closed), so as to make the pump in the suction pressure state of full liquid. The cooling water of standby pump shall be put into use continuously, and the lubricating oil level shall not be lower than the specified level. Special attention should be paid to check in winter to keep the cooling water unblocked and avoid freezing.

5. The standby pump shall be turned as required.

6. (after shutdown) for the pump to be overhauled, close the nitrogen inlet valve of dry gas sealing system first after shutdown (cooling), release the pressure in the sealing chamber, and then completely discharge the liquid in the pump and cooling water in the cooling system, so that the pressure in the pump body drops to zero, the remaining materials in the pump are purged clean, all valves are closed, and contact the substation for power failure. Site treatment shall meet HSE requirements.