输送碱液的柱塞计量泵不出液怎么办？
柱塞式计量泵因其结构简单、维护方便、效率高等优点在农业上得到了广泛的应用，但也因其有时不能供水而带来麻烦。
主要有三个原因
首先，VAREM柱塞计量泵的进气管和柱塞计量泵中有空气。
（1） 有些用户在启动泵前没有充足水，有时似乎水已经从排气孔溢出，但空气在不旋转泵轴的情况下完全排出，导致进气管或泵体中残留少量空气。
（2） 与VAREM柱塞计量泵接触的进水管水平段，在逆流方向上应有0.5%以上的下降坡度，与水泵进口连接的端部应为z高，不得完全水平。如果向上倾斜，空气将留在进水管中，从而降低水管和水泵中的真空度，影响吸水。
（3） 由于长期使用，柱塞计量泵的填料已磨损或填料被压得过松，导致填料与泵轴套之间的间隙有大量水喷出。因此，外部空气从这些间隙进入泵内，影响水的提升。
（4） 由于水下长期存在潜势，水泵运行后进水管水面不断下降。当这些孔从水中出来时，空气从这些孔进入进水管。（5） 进水管弯头处的裂纹和进水管与水泵连接处的微小缝隙都可能导致空气进入进水管。
二是变量活塞计量泵转速过低
（1） 人为因素。由于原电机损坏，相当一部分用户随机配另一台电机驱动，造成流量小、水头低，甚至没有供水。
（2） 传动带磨损。目前有许多大型水泵采用皮带传动，由于长期使用，传动皮带磨损松动，出现打滑现象，从而降低了水泵的转速。
（3） 安装不当。如果两个皮带轮中心距过小或两轴不平行，则传动带紧边安装在其上，导致缠绕角过小，两个皮带轮直径计算错误，耦合轴驱动的水泵两轴之间偏心过大，水泵的速度会改变。
（4） 计量泵本身的机械故障。泵叶轮松动或轴轴承变形松动，可能与泵轴直接摩擦。
（5） 动力机器维护未记录。由于绕组烧坏，电动机失去励磁。检修时改变绕组匝数、线径、接线方式，或检修中未完全消除的故障，也会改变水泵的转速。
三是VAREM计量泵吸入扬程过大，有的液位较深，有的液位较平，忽视了泵的允许吸入压头，导致吸水量少或不吸水。必须知道，在泵的进水口处可以建立的真空度是有限度的。绝对真空下的吸入压头约为10 m水柱高，而VAREM计量泵无法建立绝对真空。而且真空度过大，容易使泵内的水气化，不利于泵的工作。因此，每台柱塞计量泵都有其z大的允许吸入压头，一般在3到8.5米之间。安装泵时，不能简单方便。
有时计量泵工作时，不能产生溶液。怎么了？下面让上海龙亚泵阀制造有限公司的工作人员给我们详细介绍一下：
（1） 检查计量泵电机是否工作。如果不工作，说明马达或电控电路有问题。注：一般情况下，由于二氧化氯发生器回路设有过载保护装置，电动机不工作，电动机不损坏。此时，打开二氧化氯发生器方形控制器中的方形控制盒面板，按下下面一排右侧热继电器上的蓝色按钮（复位按钮），使计量泵正常工作；如果计量泵仍不能正常工作，合格的电工应根据制造商提供的二氧化氯发生器电路图检查相关电路。
（2） 检查给药管或药管内有无杂质堵塞管路。如有杂质，应及时清除。
（3） 松开进药管或出药管的接头，排出各自管路中的空气。
How to do if the plunger metering pump can't discharge the liquid?
Plunger metering pump is widely used in agriculture because of its simple structure, convenient maintenance and high efficiency, but it also brings trouble because it can not supply water sometimes.
There are three main reasons
First, there is air in the intake pipe and plunger metering pump of the varem plunger metering pump.
(1) Some users do not have enough water before starting the pump, sometimes it seems that the water has overflowed from the exhaust hole, but the air is completely discharged without rotating the pump shaft, resulting in a small amount of air remaining in the intake pipe or pump body.
(2) The horizontal section of the water inlet pipe in contact with the water pump should have a descending slope of more than 0.5% in the counter current direction, and the end connected with the water pump inlet should be Z high, not completely horizontal. If it tilts upward, the air will stay in the water inlet pipe, thus reducing the vacuum degree in the water pipe and water pump and affecting the water absorption.
(3) Due to long-term use, the packing of the pump has been worn or the packing has been pressed too loose, resulting in a large amount of water ejecting from the gap between the packing and the pump shaft sleeve. Therefore, external air from these gaps into the pump, affect the water lift. (4) Due to the long-term underwater potential, the water surface of the water inlet pipe continuously drops after the operation of the pump. When these holes come out of the water, air enters the inlet pipe through these holes. (5) The cracks at the elbow of the inlet pipe and the tiny gap between the inlet pipe and the water pump may cause the air to enter the inlet pipe.
Second, the speed of variable piston metering pump is too low
(1) Human factors. Due to the damage of the original motor, quite a number of users are randomly equipped with another motor drive, resulting in small flow, low water head, and even no water supply.
(2) The drive belt is worn. At present, many large water pumps adopt belt drive. Due to long-term use, the drive belt is worn and loose, resulting in sliding phenomenon, thus reducing the speed of the water pump.
(3) Improper installation. If the center distance of the two pulleys is too small or the two shafts are not parallel, the tight side of the drive belt is installed on it, resulting in too small winding angle, wrong calculation of the diameter of the two pulleys, too large eccentricity between the two shafts of the water pump driven by the coupling shaft, and the speed of the water pump will change.
(4) Mechanical failure of the pump itself. The pump impeller is loose or the shaft bearing is deformed and loose, which may cause direct friction with the pump shaft.
(5) Power machine maintenance is not recorded. The motor lost its excitation due to the burning out of the winding. During maintenance, changing the number of turns, wire diameter and wiring mode of the winding, or the faults not completely eliminated in maintenance, will also change the speed of the water pump.
Third, the suction head of varem metering pump is too large, some liquid level is deep, some liquid level is flat, and the allowable suction head of the pump is ignored, resulting in less or no water absorption. It must be known that there is a limit to the degree of vacuum that can be established at the water inlet of the pump. The suction head under absolute vacuum is about 10 m water column, while the varem metering pump cannot establish absolute vacuum. And the vacuum is too large, easy to make the water in the pump gasification, not conducive to the work of the pump. Therefore, each plunger metering pump has its own Z large allowable suction head, generally between 3 and 8.5 meters. It is not easy to install the pump.
Sometimes the VAREM solution pump can not work. What's up? Let's have a detailed introduction from the staff of Shanghai Longya pump valve manufacturing Co., Ltd
(1) Check whether the metering pump motor works. If it doesn't work, there is something wrong with the motor or electric control circuit. Note: in general, as the circuit of chlorine dioxide generator is equipped with overload protection device, the motor will not work and will not be damaged. At this time, open the square control box panel in the square controller of the chlorine dioxide generator, and press the blue button (reset button) on the right thermal relay of the lower row to make the metering pump work normally; if the metering pump still cannot work normally, the qualified electrician shall check the relevant circuits according to the circuit diagram of the chlorine dioxide generator provided by the manufacturer.
(2) Check whether there is any impurity in the dosing pipe. If there are impurities, they should be removed in time.
(3) Loosen the joint of the medicine inlet pipe or the medicine outlet pipe to discharge the air in their respective pipes.