Basic engineering devices such as valves contribute to almost every complex system. These mechanical/electromechanical devices regulate media flow and come in dozens of unique varieties; to see all the different types of valves, visit our understanding valves article. The diaphragm valve will be the focus of this article, and we will explore what they are, how they work, and the different types available. Through this investigation, this article should help decide if diaphragm valves could be useful, and how to choose the correct version for a given application.
What are diaphragm valves?The problem with a standard pneumatic diaphragm valve is that it’s just a single seat valve with an inlet, an outlet and an actuator on it. The diaphragm opens and closes to let flow through the valve. With a lot of valves used in industry, you can have a two-way valve and a three-way valve, so you have a third port inside the valve and the actuator closes one port and opens another.
You can’t do that with a traditional diaphragm valve because it’s only a two-way valve. Bürkert introduced the Robolux valve, which employs two pistons in one actuator to create a three-way type diaphragm valve.Diaphragm valves use a flexible diaphragm connected to a compressor by a stud which is molded into the diaphragm. Instead of pinching the liner closed to provide shut-off, the diaphragm is pushed into contact with the bottom of the valve body to provide shut-off. Manual diaphragm valve is ideal for flow control by offering a variable and precise opening for controlling pressure drop through the valve. The handwheel is turned until the desired amount of media is flowing through the system. For start and stop applications, the handwheel is turned until the compressor either pushes the diaphragm against the bottom of the valve body to stop flow or lifts off the bottom until flow is able to pass through.