Noise is one of the most common problems when mechanical equipment is running. In order to better use and maintain equipment, we need to have a certain ability to distinguish whether it is normal operating noise or noise caused by equipment failure. And the noise generated by different parts also means that there may be different fault problems in the equipment. Shanghai Xizhiquan is a professional fire pump manufacturer, and the company's professional engineers will share with you various reasons for the noise of the motor and coupling.

1. Motor noise
When the motor is noisy, we need to distinguish whether it is the airflow noise of the motor cooling fan or other possible abnormal noises of the motor. The main causes of abnormal noise are as follows:

a) The frictional noise generated between the cooling fan and the fan cover can be checked by removing the fan cover to see if the noise disappears. You can make a judgment and adjust the fan blades and fan cover to solve this problem.

b) There are two main reasons for the failure of the motor rotor bearing. One is that the bearing is rusted due to water ingress, and the other is that the motor heats up abnormally. It is necessary to replace the motor bearing to solve the abnormal sound.

2. Coupling running noise
For a water pump with an elastic coupling, if the coupling part produces periodic abnormal noises and rubber powder falls off during operation, it can be basically judged that the noise is caused by poor alignment between the pump shaft and the motor shaft, and it needs to be shut down Re-align the shaft.

The fire pump is an indispensable type of equipment in the fire water supply system. Besides the fire pump and motor, what other equipment should be included? The following Shanghai Xizhiquan will popularize it for you.

1. Dual power supply cabinets that provide electrical energy for the fire protection system
2. In order to ensure the normal start and operation of the pump motor, the necessary control circuit is the starter cabinet
3. Pipeline valves, switch pressure gauges, etc., which can ensure normal water pressure.
The above several major components can form a complete fire water supply system, all of which are indispensable.

When inspecting the water supply system, not only the water pumps and motors are inspected, but also the power supply, start-up control cabinet and pipe valves also need to be inspected regularly, so as to ensure that the entire fire extinguishing water system can operate normally when a fire comes.

working principle

Fire pump check valve refers to the valve that relies on the flow of the medium itself to automatically open and close the disc to prevent the backflow of the medium, also known as check valve, one-way valve, reverse flow valve and back pressure valve. The check valve is a kind of automatic valve, its main function is to prevent the reverse flow of the medium, the reverse rotation of the pump and the drive motor, and the discharge of the container medium. Check valves are also used on lines that supply auxiliary systems where the pressure may rise above system pressure. Check valves can be mainly divided into swing check valves (rotating according to the center of gravity) and lift check valves. The function of this type of check valve is to only allow the medium to flow in one direction and prevent the flow in the opposite direction. Usually this kind of valve works automatically. Under the action of fluid pressure flowing in one direction, the valve disc opens; when the fluid flows in the opposite direction, the valve seat is acted on by the fluid pressure and the self-weight of the valve disc to cut off the flow.

Among them, the check valve belongs to this type of valve, which includes swing check valve and lift check valve. The swing check valve has a hinge mechanism, and a door-like disc freely leans on the inclined seat surface. In order to ensure that the valve clack can reach the proper position of the seat surface every time, the valve clack is designed in the hinge mechanism, so that the valve clack has enough swing space, and makes the valve clack truly and comprehensively contact with the valve seat. The disc can be made entirely of metal, or it can be inlaid with leather, rubber, or a synthetic cover on the metal, depending on the performance requirements. When the swing check valve is fully open, the fluid pressure is almost unimpeded, so the pressure drop through the valve is relatively small. The disc of the lift check valve is located on the sealing surface of the valve seat on the valve body. Except that the valve disc can rise and fall freely, the rest of the valve is like a globe valve. The fluid pressure makes the valve disc lift from the sealing surface of the valve seat, and the backflow of the medium causes the valve disc to fall back to the valve seat and cut off the flow. According to the conditions of use, the disc can be of all-metal structure, or in the form of a rubber pad or rubber ring inlaid on the disc frame. Like the globe valve, the passage of fluid through the lift check valve is also narrow, so the pressure drop through the lift check valve is larger than that of the swing check valve, and the flow rate of the swing check valve is limited. rare.

Fire pump, vacuum technology is a technology that uses imported vacuum pumps, vacuum units and other vacuum systems to complete specific processes, and is widely used in various industrial production and scientific research work. Such as: petroleum (vacuum distillation), chemical industry, canned food, metallurgy, light bulbs and electron tubes and other production, the equipment generally adopts vacuum technology.

Vacuum pump Vacuum level Vacuum technology

The level of vacuum is determined by the remaining pressure after the air and other material vapors in the container are drawn out. The more pumped out, the lower the pressure inside the container, that is, the higher the vacuum. However, Yazhiled Electromechanical Technology reminds everyone that there is no absolute vacuum. The level of vacuum is represented by "vacuum degree", and its unit is mmHg or "Torr". 1 Torr is 1 millimeter of mercury.


Fire pumps and metering pumps are mainly composed of three parts: power drive, fluid delivery and regulation control. The power drive device drives the fluid delivery diaphragm to reciprocate through the mechanical linkage system:

The diaphragm (piston) will be inhaled by the delivery fluid in the first half of the stroke and discharged from the pump head in the second half; therefore, changing the reciprocating frequency of the stroke or the stroke length of each reciprocating movement can achieve the purpose of adjusting the fluid delivery volume . Precise processing accuracy ensures the pumping volume each time and realizes the precise metering of the conveyed medium.



Metering pump basic working principle

Due to the difference in power drive and fluid delivery methods, metering pumps can be roughly divided into two types: plunger type and diaphragm type.

1. Plunger metering pump

There are mainly two kinds of ordinary valve pumps and valveless pumps. Piston metering pumps are widely used in the petrochemical industry because of their simple structure and high temperature and high pressure resistance. Aiming at the deficiency of ordinary plunger pumps for high-viscosity media under high-pressure conditions, a valveless rotary plunger metering pump has received more and more attention, and is widely used in high-viscosity media such as syrup, chocolate and petroleum additives. metered addition. Due to the structural disadvantage of the inability to achieve complete isolation between the metered medium and the lubricant in the pump, plunger metering pumps are subject to many limitations in fluid metering applications with high anti-pollution requirements.

2. Diaphragm metering pump

As the name suggests, the diaphragm metering pump uses a specially designed and processed flexible diaphragm to replace the piston, and realizes reciprocating motion under the action of the driving mechanism to complete the suction-discharge process. Due to the isolation effect of the diaphragm, the isolation between the fluid to be metered and the driving lubrication mechanism is truly realized structurally. The high-tech structural design and the selection of new materials have greatly improved the service life of the diaphragm, coupled with the excellent corrosion resistance of the composite material, the diaphragm metering pump has become the main pump type in fluid metering applications. Among the members of the diaphragm metering pump family, the hydraulically driven diaphragm pump uses oil to evenly drive the diaphragm, which overcomes the shortcomings of excessively concentrated force on the diaphragm of the pump under the mechanical direct drive method, and improves the life of the diaphragm and the upper limit of the working pressure. In order to overcome the working failure caused by the diaphragm damage that may occur in single-diaphragm metering pumps, some metering pumps are equipped with diaphragm damage to realize automatic chain protection when the diaphragm is broken; the metering with double-diaphragm structure pump head further improves its safety. , suitable for applications that are particularly sensitive to security protection.

As a kind of diaphragm metering pump, the electromagnetic drive metering pump uses electromagnets to generate pulsating driving force, which saves the motor and speed change mechanism, making the system small and compact, and is an important branch of small-range low-pressure metering pumps.

scope of application
It is suitable for transporting lubricating oil without solid particles and fibers, non-corrosive, temperature not higher than 120oC, viscosity of 5-1500cst or other liquids with similar properties to lubricating oil.
It can be used as a transmission and booster pump in the oil delivery system. In the fuel system, it can be used as a fuel pump for delivery, pressurization and injection. In all industrial fields, it can be used as lubricating oil pump.
The gear pump mainly consists of gear, shaft, pump body, pump cover, safety valve, shaft end seal and other components. The gear has high hardness and strength after heat treatment, and all the moving parts in the pump are lubricated by the medium it transports.
The pump has safety structural features:
There are well-designed oil drain and oil return grooves in the pump, which minimize the torque force of the gears during work, so the bearing load is small, the wear is small, and the pump efficiency is high.
The pump is equipped with a safety valve for overload protection. However, it cannot be used as a pressure reducing valve for long-term work, and it can be installed separately in the pipeline if necessary. The valve acts as overload protection. However, it cannot be used as a pressure reducing valve for long-term work, and it can be installed separately in the pipeline if necessary.

Fire pump, non-clogging sewage pump is a product with novel structure successfully developed on the basis of repeated research on the technology of similar products at home and abroad. The pump integrates self-priming and non-clogging sewage pumping. The pump body and the unique design of the impeller flow path, like general self-priming clean water pumps, do not need to install bottom valves and irrigation and diversion, and can also absorb and discharge large-particle solids and long-fiber impurities. Widely used in municipal sewage projects, river pond breeding manure treatment, sedimentation of waste ore impurities, light industry, papermaking, food, chemical, pharmaceutical, electric power, slurry and mixtures and other chemical media such as impurity pumps.
The non-clogging sewage pump is a kind of pump product in which the pump and the motor are integrated and submerged into the liquid at the same time. Compared with the general horizontal pump or vertical sewage pump, the non-clogging sewage pump has the following advantages:
1. Compact structure, small footprint. The sewage pump can be installed directly in the sewage tank because it works submerged in the liquid. There is no need to build a special pump room to install the pump and machine, which can save a lot of land and infrastructure costs.
2. Easy installation and maintenance. Small sewage pumps can be installed freely, and large sewage pumps are generally equipped with automatic coupling devices for automatic installation, and installation and maintenance are quite convenient.
3. Long continuous operation time. Because the pump and the motor are coaxial, the shaft is short, and the rotating parts are light in weight, the load (radial) on the bearing is relatively small, and the service life of the sewage pump is much longer than that of ordinary pumps.
4. There is no problem of cavitation damage and water diversion. Especially the latter point brings great convenience to the operator.
5. Small vibration and noise, low motor temperature rise, no pollution to the environment.

Fire water pump, diaphragm pump is a new type of conveying machinery, and it is the most popular type of pump in China at present. Using compressed air as the power source, it can pump all kinds of corrosive liquids, liquids with particles, high viscosity, volatile, flammable and highly toxic liquids.
Due to the above characteristics of the pneumatic diaphragm pump, the diaphragm pump is gradually invading the market of other pumps in the world since its birth, and occupies a part of it. For example, the diaphragm pump has already occupied a dominant position in the painting and ceramic industries, while in other industries, such as environmental protection, wastewater treatment, construction, sewage, and fine chemicals, it is expanding its market share and has irreplaceable advantages for other pumps. status. The advantages of air-operated diaphragm pumps are:
1. Because air is used as power, the flow rate is automatically adjusted with the change of back pressure (outlet resistance), which is suitable for medium and high viscosity fluids. The operating point of the centrifugal pump is set based on water. If it is used for a fluid with a slightly higher viscosity, it needs to be equipped with a reducer or a frequency conversion speed controller, and the cost will be greatly increased. The same is true for the gear pump.
2. Pneumatic pumps are reliable and low-cost in flammable and explosive environments, such as fuel delivery, because: first, sparks cannot be generated after grounding; second, no heat is generated during work, and the machine will not overheat; Three, the fluid will not be overheated because the diaphragm pump has the least agitation of the fluid.
3. In places with bad construction sites, such as construction sites, industrial and mining wastewater discharge, due to the many impurities and complex components in the sewage, the pipelines are easy to be blocked, so the load on the electric pump is too high, and the motor is easily damaged due to heat. The air-operated diaphragm pump can pass particles and the flow rate is adjustable. When the pipeline is blocked, it will automatically stop until it is unobstructed.
4. In addition, the diaphragm pump is small in size and easy to move. It does not need a foundation, occupies a very small area, and is easy and economical to install. Can be used as a mobile material transfer pump.
5. In the treatment of hazardous and corrosive materials, the diaphragm pump can completely separate the materials from the outside world.
6. Or some tests ensure that no impurities contaminate raw materials.
7. It can be used to transport fluids with relatively unstable chemical properties, such as: photosensitive materials, flocculation fluid, etc. This is because the shear force of the diaphragm pump is low and has little physical impact on the material.
Precautions for operation and operation of multi-purpose pneumatic diaphragm pump:
1. Ensure that the largest particles contained in the fluid do not exceed the maximum diameter of particles that can safely pass through the pump.
2. The intake pressure should not exceed the maximum allowable operating pressure of the pump. Compressed air with a pressure higher than the rated pressure may cause personal injury and property loss and damage the performance of the pump.
3. Ensure that the pipeline system of the pump pressure can withstand the highest output pressure achieved, and ensure the cleanliness and normal working conditions of the driving air system.
4. Static sparks may cause explosions, resulting in personal casualties and property losses. Use wires with a sufficiently large cross-sectional area as required to properly and reliably ground the grounding screw on the pump.
5. The grounding requirements are in compliance with local laws and regulations and some special requirements on site.
6. Fasten the pump and the connecting pipe joints to prevent static sparks from vibration, impact and friction. Use antistatic hose.
7. To periodically check and test the reliability of the grounding system, the grounding resistance is required to be less than 100 ohms.
8. Keep good exhaust and ventilation, keep away from flammable, explosive and heat sources.
9. There may be solid matter in the exhaust of the pump. Do not face the exhaust port to the work area or people to avoid personal injury.
10. When the diaphragm fails, the conveyed material will be ejected from the exhaust muffler.
11. When transporting flammable and toxic fluids, please connect the drain to a safe place away from the working area.
12. Please use a pipe with a smooth inner wall of at least 3/8" inner diameter to connect the exhaust port and the muffler.

Water pump method one: the installation of the pump set should be accurate and reliable, and there should be no obvious vibration during operation. If the pump makes abnormal noise when pumping water, or the bearing is hot to the touch (the temperature is higher than 60°C) and the water seepage in the seal of the pump shaft is more than 60 drops per minute, the cause must be found out and the fault should be eliminated in time.