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A Brief Summary of Diaphragm Valves

A diaphragm valve is a bi-directional, on/off throttle valve used to control fluid by regulating the area through which media (such as a fluid) can enter and exit the valve, thereby changing its speed and velocity. The name diaphragm valve comes from the thin, flexible membrane used to control the opening and closing of the valve. They can be made from materials including stainless steel, plastic, or even single-use materials. Diaphragm valves are similar to pinch valves, but use a linear compressor to push the thin diaphragm into contact with the valve body. They provide discrete and variable pressure control and can be either manually or automatically actuated.

Diaphragm valves are clean, leak-proof, safe, effective, and easy to maintain valves that are ideal for moderate pressure and temperature applications where stop/start fluid control is required. They are simple in both construction and operation. In a diaphragm valve, a valve actuator is in contact with the inner membrane of the valve in its open position. When the user wants to close the valve, the actuator is pressed and/or turned and the membrane is pushed into the edge of a solid stopper, shutting the valve. Some diaphragm valves feature partially open/restricted positions where the membrane is partially closed, allowing a controlled amount of flow.

There are two main types of diaphragm valves used in industrial applications: weir-type and straight-through. Weir-type diaphragm valves are the most common design available. They feature a raised lip or saddle design which makes them tailored to small flow control and keeps them leak-proof due to a bonnet that covers the diaphragm and actuator. This also makes them ideal for dangerous or corrosive liquid and gas, as the bonnet ensures any failure with the membrane will be contained. Additionally, the sloped body of this valve makes them inherently self-draining. However, this draining can occur in both directions, which may not be ideal for certain uses. Weir-type valves are primarily used for clean, homogeneous fluids, as viscous slurries and sediments can build up on the sides of the saddle. Weir-type valves are most commonly used in food/chemical, gas production, corrosive, and water applications.

The straight-through diaphragm valve is similar to weir-type, but has a completely straight pathway rather than a raised lip/saddle. The membrane in straight-through diaphragm valves are typically more flexible and allow for farther travel distances, as it must touch the very bottom of the valve. Due to the more flexible membranes, valves of this type have shorter lifespans than weir-type designs and therefore must be serviced and replaced more frequently. Straight-through diaphragm valves are used for slurries, viscous fluids, and other applications where blocking must be reduced. They are also ideal for bi-directional flow patterns, as the lack of a saddle ensures that changing from inlet to outlet is not impeded.

Due to the fact that they are cheap, effective, and come in multiple types, diaphragm valves have a vast and diverse range of applications. Though there are many more, the most common sectors where diaphragm valves are used include water treatment facilities, pharmaceutical manufacturing systems, food/chemical processing plants, power industries, vacuum services, breweries, corrosive applications, and more. Wherever your diaphragm valve will be used, ensure you are getting it from a trusted source.

For all types of diaphragm valves and much more, look no further than NSN Sphere. Owned and operated by ASAP Semiconductor, we can help you find all types of parts for the aerospace, civil aviation, defense, electronics, industrial, and IT hardware markets. Our account managers are always available and ready to help you find all the parts and equipment you need, 24/7-365. For a quick and competitive quote, email us at or call us at 1-714-705-4780. Let us show you why we consider ourselves the future of purchasing.

About Author - Charles Howard

Charles Howard is a passionate aviation enthusiast with over 15 years of experience in the industry. Holding a degree in Aerospace Engineering, Charles has worked with some of the top aerospace companies and has been involved in various groundbreaking projects that have shaped modern aviation.

Currently Charles is leading the content marketing team at NSN Sphere. Charles's passion for writing is matched only by his commitment to delivering value to his readers. His blogs are known for their clarity, creativity, and ability to distill complex topics into easily digestible and enjoyable reads.


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