Mucon Powder Valves and Components

The Mucon Iris Diaphragm Valve – The History of the Innovative Flow Control Valve

The Original Mucon Iris Diaphragm Valve

June 15th, 2017

Several different types of valves are available in the powder processing industry. One, in particular, has proven itself time and again as the strong, reliable and innovative flow control solution – the Iris Diaphragm Valve (IDV).

The revolutionary design of the IDV is the creative invention of two brothers working together in the photographic industry in the late 1940s. Back then, powder and granular gelatin were used in the manufacturing process of photographic film. Traditional slide valves were used to control the flow of the granular gelatin, but the valves often seized and jammed due to the sticky nature of the gelatin. The slide valve would then leak making the work environment very uncomfortable for the operators. It would also produce substantial product waste resulting in significant financial losses.

The two brothers found a solution to this problem with the invention of the Iris Diaphragm Valve. They based the new valve on an extremely simple principle; when a balloon is blown up and the end is twisted, the air does not escape. The IDV is based on this straightforward principle.

How does it work?

A tube of flexible material, the diaphragm, is manufactured with built-in retaining rings at each end. One end is held in position while the other is rotated 180°. The 180° rotation completely closes the orifice providing an equivalent load support of a steel plate slide valve. The closed diaphragm resembles the iris of a camera, hence the Iris in Iris Diaphragm Valve.

How the Mucon Iris Diaphragm Valve WorksMaterial of Construction

When the two brothers developed the Iris Diaphragm Valve prototype in their garden shed over 60 years ago, they used items readily available. They consider economic factors and the availability of the design materials. Started with the frame, they felt it was important that the mechanism is strong and supported the function of the diaphragm while holding it firmly in place. The brothers chose wood. As the IDV gained popularity in the Food, Chemical, Pharmaceutical and Plastics industries, other materials were introduced. Today, the valve body is available in aluminum, zinc and bronze alloys or stainless steel.

As the brothers considered material for the first diaphragm, they once again looked for available materials and literally used the shirt off their back. The first diaphragm was made from one of the brother’s cotton shirtsleeves.

With the completed prototype, the two brothers returned to the photo industry to test their valve. After great success, they began manufacturing the valves for production. This was the birth of Mucon, the first Iris Diaphragm Valve. Interestingly enough, the brothers chose their new company name by merging the first name of each of their wives, Muriel and Constance, thus Mucon

As time went on and Iris Diaphragm Valves were introduced to new industries, the diaphragm material changed to linen, then moving on to nylon and rubber. Today both nylon and rubber diaphragms are available along with Terylene, and Polyurethane coated fabrics. Each diaphragm is specifically manufactured with the application in mind, some with hygienic material for food or pharmaceutical ingredients while others with material for corrosive, explosive or even extremely delicate products.

Powering the Valve

For many years, hand operated IDVs were adequate for industrial use, but to cater to the many different duties throughout various industries and to handle a wide range of powders and granular materials, several operation methods were developed.

First, the pneumatic Iris Diaphragm Valve was developed to accommodate required manufacturing automation and increased output.   Still used today, the pneumatic valve features robust construction and reliable drive elements, making it suitable for the most demanding duties.

Clean Room Pass-Thru

Clean Room Pass-Thru

Also available is the electric motor IDV. Its quick operation is capable of opening and closing the valve within one second. This coupled with an infinite flow control from full bore to complete shutoff make it ideal for most applications. It is also suitable for frequent operation in harsh environments allowing the operator to adjust the valve’s flow from a safe location.


Although originally designed for the flow of sticky gelatin powder for the photographic industry, today the IDV has proven itself as one of the most versatile flow control valves for dry bulk solids and has become the standard for providing sure, gentle and strong flow control over powder and granular products. The diaphragm is capable of closing around product lumps, or even foreign bodies trapped during closure, while still providing an effective seal to smaller particles and dust. It is this unique feature that has enabled the IDV to be used for a variety of unusual and not so unusual applications around the world, for instance:

Clean Room Pass Thru

A prime example is Service Cable and Pipe Glanding. The valve is used to seal around tubes passing through a wall separating two clean rooms with slightly different pressures, eliminating the pressure loss between the rooms. The valve is manufactured in stainless steel and fitted with an FDA approved, EPDM rubber diaphragm. The combination of valve

Mucon H Iris Diaphragm Valve

Bulk Bag Discharge Stations

diameter, diaphragm material, and infinite adjustment feature allows the diaphragm to bring the tubes together and close tightly around them – accommodating different diameter tubes and a number of tubes simultaneously.


Several models of the Iris Diaphragm Valves have been engineered for use with IBCs. Their low cost, compact design, and easy action allow for precise regulation of the bulk container discharge. Their use is not limited to dry bulk solids but can also be used for pastes, slurries, and solids in suspension.

Bulk Bag Stations

The IDV has been fitted to thousands of FIBCs across the world. The multi-notched body design is ideal for maximum flow control and dust tight closure in many industrial environments including the chemical, pharmaceutical, and food industry.

Tablet in Iris Diaphragm Valve

Tablet in Iris Diaphragm Valve


The IDV has been specifically developed for the pharmaceutical, dairy and food Industry applications. It meets the stringent demands of today’s process industries including hygiene, quick disassembly without tools, and easy, thorough cleaning. With the addition of an FDA approved food grade rubber or pharmaceutical grade disposable poly liner for additional protection, the Iris Diaphragm Valve allows the smooth flow of tablets without damage.

Delicate Fish Transfer

The Iris Diaphragm Valve with a double diaphragm is so gentle that it is used on live fish transport vehicles. Upon opening the IDV, the fish simply flow through the valve to a holding area without any damage to their delicate constitution, even if they get caught in the closing of the valve. The double diaphragm design is also perfect for inline applications where no atmospheric leaking is required.

Since the original concept, millions of the Iris Diaphragm Valves have been supplied in many different sizes and varieties to a diverse range of industries. Time and again, the Iris Diaphragm Valve has proven itself the strong, reliable and versatile flow control solution for dry bulk solids. For More information on Mucon Iris Diaphragm Valves

Fish transport

Fish Transport

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