1. Preventive measures for common failures of automatic valves:

a) Regularly check and clean the water inlet filter, and replace it regularly.

b) Check the pressure difference of the valve, the working pressure difference should not be too large.

c) Check the seal of the valve, whether the sealing surface is intact.

d) Check whether the actuator has water leakage, if there is water leakage, it needs to be replaced in time.

e) Check whether the electric contact of the valve is normal, and replace the damaged parts in time.

2. Energy-saving working principle of frequency conversion water pump:

The energy-saving working principle of frequency conversion water pump is to adjust the flow rate and pressure of the pump according to the actual needs of the system. When the system needs less water, the frequency converter can adjust the speed of the pump to reduce the flow rate and pressure, so as to achieve the purpose of energy saving. When the system needs more water, the frequency converter can adjust the speed of the pump to increase the flow rate and pressure to meet the needs of the system.

a. The frequency conversion water pump is a variable frequency water pump that can adjust its output power according to the external water pressure and volume. The working principle is to change the frequency of the power supply to change the speed of the motor and the flow rate of the pump.

b. When the water pressure is low, the pump can reduce the speed or output power, thereby saving energy. When the water pressure is high, the pump can increase the speed or output power, so as to meet the water demand.

c. The use of frequency conversion technology can reduce the starting current of the pump, reduce the impact on the power grid, and improve the stability of the power grid.

When installing fire pumps, it is important to pay attention to the following:
- Ensuring the pump is correctly sized for the system
- Properly connecting the pump to its power source
- Install the fire pump in accordance with the manufacturer’s instructions
- Make sure the pump is connected to a suitable water supply
- Include appropriate strainers and filters to ensure the water supplied to the pump is free from debris
- Ensure that the fire pump is tested and inspected by a qualified technician.
- The fire pump should be installed in a dry, clean and well-ventilated place.

-The piping should be properly supported and have a sufficient number of hangers to avoid sagging or other damages in the piping due to the weight of the water.

-All valves, gauges and other accessories should be connected and tested to ensure proper operation.

-The correct suction and discharge pressure must be maintained to ensure the fire pump is able to supply the necessary pressure for any given situation.


Ball valves can play an important role in fire pumps installation, as they can help to regulate the flow of water through the pump. This can help to ensure that the pump is not over or under-pressurized and that it is operating at its optimal efficiency, saving energy and money.Ball valves can play an important role in the installation of fire pumps by providing quick shut-off points for the system. This can be beneficial for maintenance and testing, as well as for emergency situations where the fire pump needs to be quickly shut off. Additionally, ball valves can provide a better seal than other types of valves, thus reducing the risk of leaks or pressure loss.

The critical cavitation allowance of fire pumps is the minimum pressure needed to prevent the pump from cavitating, which is the formation of air bubbles in the liquid due to a decrease in pressure. Critical cavitation allowance is usually expressed in terms of net positive suction head (NPSH) and is a function of the pump's design and operating characteristics.

Plunger pumps are commonly used for fire applications, and are typically designed to operate at higher pressures than other types of pumps. This means that the critical cavitation allowance of plunger pumps can be higher than for other pumps, allowing them to operate at higher pressures without cavitating. Additionally, plunger pumps have the ability to handle higher flow rates than other types of pumps, making them ideal for firefighting applications.

The critical cavitation allowance of fire pumps is the maximum pressure drop that is allowed to occur between the pump inlet and outlet without cavitation occurring. The critical cavitation allowance is usually set at a maximum of 5% of the rated pump pressure.

Plunger pumps are often used for fire pump applications because they are capable of generating high pressures and are more reliable than other types of pumps. Plunger pumps can handle higher pressure drops than other types of pumps, which makes them ideal for fire pump applications. However, plunger pumps are more susceptible to cavitation, so the critical cavitation allowance should be monitored closely to ensure that cavitation does not occur.

The critical cavitation allowance (CCA) of a fire pump is the amount of pressure that the pump can maintain without cavitation occurring. Cavitation is a phenomenon in which air bubbles form in the pump due to the pressure drop. It can cause damage to the pump and reduce its efficiency. The CCA of a fire pump is an important parameter that must be taken into consideration when selecting the right fire pump for the application.

Plunger pumps are commonly used in fire pump applications due to their high pressure capabilities. The CCA of a plunger pump is typically higher than other types of pumps, allowing them to maintain pressure at higher levels. Additionally, plunger pumps are able to handle a wide range of viscosities, which makes them well-suited for use in firefighting applications.

A submersible sewage pump is a type of pump that is installed underwater and is used to pump out wastewater, sewage, and other liquids that contain solid particles. Submersible sewage pumps are more efficient and easier to maintain than conventional pumps as they are designed to be installed and operated underwater.

Maintenance Points for Submersible Sewage Pumps:

1. Regularly check the working condition of the pump and its components, such as the motor and bearings.

2. Check the electrical connections and wiring of the pump frequently.

3. Regularly clean and inspect the suction and discharge lines as well as the pump itself.

4. Ensure that the inlet and outlet of the pump are not blocked.

5. Lubricate the motor, bearings, and other moving parts of the pump regularly.

6. Inspect the pump for any signs of wear and tear and replace any worn-out parts.

7. Ensure that the power supply to the pump is adequate.

1. Improper installation: Fire pumps should be installed according to the manufacturer's instructions to ensure that the pump is properly sealed with the piping, and that the suction and discharge connections are properly secured.

2. Corrosion: Fire pumps should be regularly inspected and maintained to prevent corrosion that can lead to leaks.

3. Shaft misalignment: Fire pumps should be aligned properly before start-up to prevent leakage.

4. Damaged seals: Fire pumps should be inspected regularly to check for damaged seals that could be causing the leakage.

5. Improperly sized components: Fire pumps should be installed with properly sized components to ensure that the pump operates efficiently and without leakage.

6. Worn impellers: Impellers should be inspected and replaced if necessary to prevent leakage.

To install a fire pump, you should:

1. Check the manufacturer's instructions and ensure that the pump and all components are properly sized and rated for the application.

2. Assemble the pump and make sure that all connections are secure and sealed properly.

3. Align the pump and make sure that the shaft is properly aligned.

4. Check the seals for any signs of damage and replace as needed.

5. Start the pump and check for any signs of leakage.

6. Make any necessary adjustments to ensure that the pump is operating properly.

1. Maintenance of Anti-Water Pump Control Valve

a. Check the valve body and pipe joints for leakage and rust. If there is any problem, repair or replace it in time.

b. Check the valve stem for wear and tear and repair or replace it in time if necessary.

c. Check the valve core and valve seat for wear and tear and repair or replace it in time if necessary.

d. Check whether the valve stem is flexible and easy to operate.

e. Check the valve core and valve seat for rust and replace them in time if necessary.

f. Check the filter screen and replace it in time if it is blocked.

2. Application Principle of Multi-functional Control Valve

The multi-functional control valve is a kind of valve used to control the flow of fluid in the pipeline system. It is mainly composed of a valve body, a valve core, a valve seat, a valve stem and a filter screen. The valve body is connected to the pipeline system, and the valve core is connected to the valve stem. When the valve is in the open position, the valve core is pushed against the valve seat by the valve stem, which allows the fluid to flow through the valve body. When the valve is in the closed position, the valve core is pulled away from the valve seat by the valve stem, which blocks the flow of the fluid. The filter screen is used to filter out impurities in the fluid.