Diaphragm Valve – Types, Functions and Applications

A diaphragm valve is a type of valve which uses a diaphragm component to control the flow of fluid. A diaphragm is a pressure-responsive component and it is used to provide forces need to open, close or regulate fluid flow. This valve is designed to use an elastic membrane to separate fluid flow from the closing part. Diaphragm valve manufacturer produce different varieties of diaphragm valves among other types of valves. Diaphragm valves are either automatic or manual valves.

How does a diaphragm valve work?

Diaphragm valve employs the pinching method to control the flow of fluid through these valves. The diaphragm is connected to a compressor. The compressor is then connected to the valve stem. To increase fluid flow, the stem is moved upward. As such, the compressor moves further upwards and transmits its motion to the diaphragm. This makes the diaphragm move upwards. When the diaphragm moves up, it results in increased fluid flow. To close or lower fluid flow, the stem is rotated to move downwards. The downward movement of the stem transmits its motion to the compressor which then presses the diaphragm downwards and it then closes or reduces fluid flow as needed.

Types of diaphragm valves

1. Weir diaphragm valve

This is a diaphragm valve suitable for small and zero leakage fluid flow control. Diaphragm valve manufacturers produce this valve with an inclined body to enhance the self-draining feature. This type of valve is recommended for use in hazardous or corrosive fluids because the bonnet is designed to control leakage or diaphragm failure.

2. Straight-way diaphragm valve

This valve is also known as an in-line diaphragm valve. This valve is designed with a straight pathway, unlike the weir type valve. This is one of the main characteristics used to distinguish between straight-way and weir-type valves. The diaphragm used in this type of valve is more flexible. Due to the diaphragm being more flexible, the valve life service is shorter relative to that of weir type valve. This type of valve is used in different applications such as water sludge, viscous fluids, and other applications that are prone to clogging.

Other types of diaphragm valves are:

• Process diaphragm valve.
• Automatic diaphragm valve
• Diaphragm solenoid valve.
• Sanitary diaphragm valve.
• Shut-off diaphragm valve.
• Zero-static diaphragm valve.
• Manually actuated diaphragm valve among others.

Factors to consider when purchasing or selecting a diaphragm valve

1. Type of media

There are different types of diaphragm valves based on material type, application, and size. Some of these valves are best suited for corrosive and abrasive media while others are best for non-abrasive media depending on the material used to make that valve. As such, it is good to consult valve experts or the diaphragm valve manufacturer to advise on the best type of valve for that application.

2. Actuation method

Diaphragm valves operate using either manual handwheel or actuators. There are different actuators used diaphragm valves. Each of these actuators has unique advantages and disadvantages. These actuators are electric, pneumatic, and hydraulic actuators.

3. Applications conditions

These valves are meant for different fluid flow rates, temperatures, and pressure. It is very important to know the conditions of the application to help the in selecting the most economical and effective diaphragm valve for the intended application.

Applications of NTGD diaphragm valves

• These valves are used in water supply systems.
• They are used in pharmaceutical applications.
• Diaphragm valves are used in clean and dirty applications. Consult experts to know if that particular valve is suitable for the clean or dirty application.
• They are suitable for use in corrosive media.
• These valves are used in the food and beverages industries.