A diaphragm valve is a shut-off valve that uses a diaphragm as its opening and closing element to close the flow path, cut off the fluid, and separate the valve body cavity from the valve cover cavity. It is a special type of shut-off valve whose opening and closing element is a diaphragm made of a soft material, separating the valve body cavity from the valve cover cavity and the drive components. It is now widely used in various fields. Commonly used diaphragm valves include rubber-lined diaphragm valves, fluoropolymer-lined diaphragm valves, unlined diaphragm valves, and plastic diaphragm valves.
GNEE Group has been professionally manufacturing diaphragm valves for 18 years and provides selection advice. Contact us for selection advice.
Diaphragm Valve Working Principle
A diaphragm valve replaces the traditional valve core assembly with a corrosion-resistant lining and a corrosion-resistant diaphragm to achieve fluid regulation. The valve body can be made of cast iron, cast steel, or cast stainless steel, supplemented with various corrosion-resistant or wear-resistant materials, such as rubber and PTFE, as the diaphragm material.
This diaphragm design offers excellent corrosion resistance, capable of handling highly corrosive media such as strong acids and alkalis. Diaphragm valves have a compact structure, low fluid resistance, and superior flow capacity compared to other types of valves of the same specifications.
Its unique structural design completely isolates the medium from the upper chamber of the valve stem, ensuring leak-free operation, making it ideal for regulating media with high viscosity or suspended particles.
It is worth noting that due to limitations in the diaphragm and lining materials, its pressure resistance and temperature resistance are relatively weak, typically only suitable for nominal pressures of 1.6 MPa and temperatures below 150°C.
Diaphragm Valve Structure
A diaphragm valve is a type of valve that controls the flow or direction of fluid by deforming a diaphragm. Its core structure includes:
- Valve Body: Connects to the pipeline and withstands the pressure of the medium; typically made of cast iron, cast steel, stainless steel, or engineering plastics.
- Diaphragm: The opening and closing element; typically made of rubber, PTFE, or composite materials, providing excellent corrosion resistance and sealing performance.
- Valve Disc: Connected to the diaphragm and deformed by rotation or lifting.
- Valve Cover: Bolted to the valve body, forming a sealed cavity that houses the diaphragm and valve disc.
- Actuator: A manual, electric, pneumatic, or hydraulic actuator that controls the rotation or lifting of the valve disc.
- Sealing Surface: The contact surface between the diaphragm and the valve body, ensuring reliable sealing.
Performance Advantages and Limitations
Advantages
Good sealing: Large contact area between the diaphragm and valve body ensures reliable sealing, suitable for high pressure differential applications.
High corrosion resistance: The diaphragm material can be selected according to the characteristics of the medium, making it suitable for corrosive media.
Low fluid resistance: simple flow channel, low pressure drop loss, and good energy saving effect.
No leakage risk: The diaphragm completely isolates the fluid from the drive unit, making it suitable for toxic and hazardous media.
Wide range of applications: Supports various media and operating conditions, and is easy to maintain.
Limitations
Limited diaphragm life: Long-term use may lead to diaphragm aging, wear, or rupture.
Temperature limitations: High-temperature media may accelerate diaphragm aging, requiring the use of special materials.
Limited regulation performance: mainly used for on/off control, with low flow regulation accuracy.
Larger size: Compared to ball valves, diaphragm valves are larger and take up more space.
Higher cost: Compared to ordinary valves, diaphragm valves are more expensive and have higher maintenance costs.
Applications
Diaphragm valves are widely used in the following industries:
- Chemicals and Pharmaceuticals: Controlling corrosive, toxic, and high-purity media.
- Food and Beverages: Compliant with GMP standards, used for cleanroom piping control and dispensing systems.
- Water Treatment and Environmental Protection: Controlling wastewater flow, chemical dosage, and reverse osmosis systems.
- Semiconductor Manufacturing: Used for the transport and control of high-purity chemicals.
- Paper and Printing: Removing condensate in drying sections, calenders, and other equipment to improve paper quality.
- Aerospace: Used in fuel systems, hydraulic systems, and environmental control systems.
Diaphragm valve factory
GNEE Group has been a professional manufacturer of diaphragm valves for 18 years. We can customize diaphragm valves according to your drawings. Send us your drawings to get a quote.