Diaphragm valves control flow by moving a flexible diaphragm toward or away from a sealing surface. The diaphragm forms a barrier between the process medium and much of the valve operating mechanism.
Multiple diaphragm valves can be incorporated into manifolds or distribution assemblies when a process requires several branches, isolation points, sampling connections, or controlled flow paths.
Valve Operation
How Diaphragm Valves Work
A diaphragm valve uses a flexible membrane that moves under mechanical or actuator force. Pressing the diaphragm against a sealing surface blocks the process passage.
Retracting the diaphragm opens a path for the fluid to move through the valve body.
Industrial diaphragm valves are available in different body configurations, materials, actuation methods, and sealing designs to suit different fluid systems.
Valve Geometry
Weir-Type Diaphragm Valves
One common diaphragm valve arrangement uses a raised section within the flow passage called a weir.
The diaphragm moves downward against the weir to stop flow. When the diaphragm lifts, fluid travels over and around the raised sealing area.
Additional information about weir valves provides context for this widely used diaphragm valve configuration.
Process Drainability
Zero-Static Manifold Configurations
Some fluid systems place particular emphasis on reducing areas where process fluid can remain trapped when the system is drained or cleaned.
Valve-body and manifold geometry can be designed so branch connections are positioned close to the main process passage.
Specialized zero-static valves are associated with configurations intended to minimize stagnant areas around process branches.
Actuation
Manual and Automated Diaphragm Valves
Diaphragm valves can be operated manually or connected to actuators for remote and automated operation.
Pneumatic actuators are useful in process systems where a valve must respond to control signals or programmed production sequences.
Automated valve manifolds can centralize several controlled process branches and coordinate their operation through a larger control system.
Materials
Diaphragm and Valve Body Materials
The process medium contacts the valve body and diaphragm, so their materials must be compatible with the fluid, operating temperature, pressure, and cleaning conditions.
Material selection can also be influenced by corrosion resistance, required cleanliness, mechanical durability, and surrounding process equipment.
Engineering
Diaphragm Valve Manifold Design Factors
Applications
Diaphragm Valve Manifold Applications
Diaphragm valve manifolds can be used in process systems requiring isolation, fluid distribution, automated switching, sampling, cleaning, or separation between process media and valve operating mechanisms.
Their suitability depends on the fluid being handled, system cleanliness requirements, pressure, temperature, valve size, and actuation method.