Diaphragm valves are linear motion valves used for start-stop and throttling applications. The two most common types of diaphragm valve are the weir and straight through types.

The diaphragm disc is usually manufactured from a flexible, but durable material. A compressor is installed on the upper side of the diaphragm. The compressor can be lowered to close the valve or raised to open the valve.

This type of valve has a large seating surface area and this ensures that the valve seats (closes) correctly. Diaphragm valves are often used in the chemical industry where the disc material is chosen to be corrosive and erosion resistant; the large seating area is also a benefit as this reduces the risk that the valve will pass (leak). Typical diaphragm materials include plastics, synthetic and natural rubbers.


The diaphragm valve operates using a compressor which is lowered or raised in order to press the diaphragm closed, or to separate the diaphragm from the seat. The response time is very fast and sealing very reliable.

3D Model Components

This 3D model contains all common parts of a diaphragm valve, these include:

  • Stem
  • Actuator
  • Bonnet
  • Disc
  • Seat
  • Packing
  • Body

How Diaphragm Valve Work

The below video is an extract from our Introduction to Valves Online Video Course.


Encyclopedia - saVRee