1. Definition and characteristics of diaphragm valve

Diaphragm valve is a special valve whose opening and closing component is an elastic diaphragm. The diaphragm valve uses the movement of the diaphragm to control the on and off of the fluid. It has the characteristics of no leakage, fast response, and low operating torque. Diaphragm valves are particularly suitable for situations where media contamination needs to be prevented or where rapid opening and closing is required.

2. Classification and structure of diaphragm valves

Diaphragm valves can be divided into: ridge type, DC type, cut-off type, straight-through type, weir type, right-angle type, etc. according to the structure; they can be divided into: manual, electric, pneumatic, etc. according to the driving mode. Diaphragm valve is mainly composed of valve body, valve cover, diaphragm, valve seat, valve stem and other components.

3. Working principle of diaphragm valve

The working principle of the diaphragm valve is: The working principle mainly relies on the movement of the diaphragm to control the flow of fluid. The diaphragm valve consists of an elastic diaphragm and a compression member that drives the diaphragm to move. When the valve is closed, a seal is formed between the diaphragm and the valve body and bonnet, preventing fluid from passing through. When the valve opens, the force provided by the operating mechanism causes the compression member to rise, causing the diaphragm to rise from the valve body and the fluid begins to flow. By adjusting the force provided by the operating mechanism, the opening of the valve can be controlled, thereby controlling the flow of fluid.

4. Key points for selecting diaphragm valves

Select the appropriate diaphragm material and valve body material according to the medium characteristics.

Select the appropriate diaphragm valve model and specifications based on the working pressure.

Consider how the valve operates, whether it is manual, electric or pneumatic.

Consider the working environment and service life requirements of the valve.

5. Diaphragm valve performance parameters

The main performance parameters of the diaphragm valve include: nominal pressure, nominal diameter, applicable medium, applicable temperature, driving mode, etc. These parameters require special attention when selecting and using diaphragm valves.

6. Application scenarios of diaphragm valves

Diaphragm valves are widely used in food, medicine, environmental protection, chemical and other industries, especially in situations where it is necessary to prevent media contamination and open and close quickly, such as sewage treatment, food processing, etc.

7. Installation of diaphragm valve

1. Preparation before installation

Ensure that the model and specifications of the diaphragm valve comply with the design requirements.

Check the appearance of the diaphragm valve to ensure there is no damage or rust.

Prepare necessary installation tools and materials.

2. Detailed explanation of installation steps

According to the pipeline layout, determine the installation position and direction of the diaphragm valve.

Install the diaphragm valve onto the pipe, ensuring that the valve body is parallel to the pipe flange surface and fits tightly.

Use bolts to fasten the valve body to the pipe flange to ensure a secure connection.

Check the opening and closing status of the diaphragm valve to ensure that the diaphragm can move freely and there is no leakage.

3. Installation precautions

Avoid damaging the diaphragm during installation.

Make sure the diaphragm valve’s actuation method matches the operating mechanism.

Make sure the diaphragm valve is installed in the correct direction to avoid affecting its normal operation.

4. Common installation problems and solutions

Problem: Diaphragm valve leaks after installation. Solution: Check whether the connection is tight, and retighten it if it is loose; check whether the diaphragm is damaged, and replace it if so.

Problem: The diaphragm valve is not flexible in opening and closing. Solution: Check whether the operating mechanism is flexible, and clean it if there is any jamming; check whether the diaphragm is too tight, and adjust it if so.

5. Post-installation inspection and testing

Check the appearance of the diaphragm valve to ensure there is no damage or leakage.

Operate the diaphragm valve and check its opening and closing status to ensure it is flexible and free of obstruction.

Carry out a tightness test to ensure that the diaphragm valve does not leak when in the closed state.

Through the above steps and precautions, you can ensure the correct installation and normal operation of the diaphragm valve to meet the usage requirements.