Showing posts with label Gemu. Show all posts
Showing posts with label Gemu. Show all posts

Friday, February 23, 2018

Industrial Diaphragm Valves

sectional drawing weir type diaphragm valve with pneumatic actuator
Section drawing of diaphragm valve, weir type,
with pneumatic actuator.
Image courtesy Gemu Valves, Inc.
Diaphragm valves are named for the means employed in their design to restrict the path of fluid flow through the valve. Most valve designs employ a rigid solid shape which is repositioned in the fluid path to regulate flow. Diaphragm valves are somewhat unique in their use of a flexible material that is deformed by a moving part connected to the valve operating mechanism. The diaphragm acts as the flow restrictor and seat. It also isolates the valve bonnet and stem from the flowing media.

The fluid path and diaphragm positioning and seating enable this valve type to be used for throttling or simple stop operations. They are generally tolerant of particulate matter entrained in the media. Selecting body and diaphragm materials that are compatible with the media are primary elements of achieving a successful application. The diaphragm is a wearing part and should be inspected periodically and replaced when necessary.

Diaphragm valves for industrial use are available in a range of materials and sizes to accommodate light through heavy duty applications.
  • Suitable for inert and corrosive liquid and gaseous media when proper valve body and diaphragm materials are selected
  • Bonnet and valve bodies available in metal or plastic construction
  • Insensitive to particulate media
  • Valve body and diaphragm available in various materials and designs
  • Compact design
  • Automation via pneumatic or electric means
Share your fluid process control challenges with valve application specialists. Leverage your own knowledge and experience with their product application expertise to develop an effective solution.

Wednesday, June 7, 2017

Metal Diaphragm Valves - Best Applications

pneumatically operated diaphragm valve industrial valve
Diaphragm valve, pneumatically actuated
Courtesy GEMU
There are more valve selection options available than one can count. Differing types, sizes, materials, and other special characteristics distinguish each and every product as unique in its own way. Matching the design and performance strengths of a particular valve to the requirements of an application may require some investment in time and research, but the payback can be years of trouble free performance.

Diaphragm valves are beneficial for applications requiring hermetic isolation of the valve bonnet and stem from the media. The diaphragm serves as the isolating barrier. The valves are generally tolerant of particulate matter entrained in the media, and provide good shutoff and throttling capability. Body and diaphragm materials should be selected that are compatible with the media.

Body styles are either weir or straight through design. Straight through body styles offer a less restricted flow path than the weir type, but diaphragm movement in the weir style is reduced. Diaphragms do wear and will need to be replaced at some point. Valves should be installed with good service access.

There are many variants of diaphragm valves, broadening their suitability for a wide range of industrial applications. Share your fluid process control challenges with application specialists, combining your process knowledge with their product expertise to develop effective solutions.

internal diagram of weir type diaphragm valve
Weir body style diaphragm valve
Coutesy GEMU

Friday, December 2, 2016

Diaphragm Valves For Heavy Duty Industrial Applications

industrial diaphragm valve with handle metal body and metal diaphragm
Series 611 Industrial Diaphragm Valve
Courtesy Gemü
Diaphragm valves are suitably used for applications requiring hermetic isolation of the valve bonnet and stem from the flowing media. They also are capable of throttling flow and are generally tolerant of particulate matter entrained in the media. Selecting body and diaphragm materials that are compatible with the media are primary elements of achieving a successful application.

Gemü, a globally recognized manufacturer of diaphragm valves and other control components, offers a line of industrial metal diaphragm valves available in a range of materials and sizes to accommodate heavy duty applications.
  • Suitable for inert and corrosive liquid and gaseous media
  • Chemical resistant bonnet
  • Insensitive to particulate media
  • Valve body and diaphragm available in various materials and designs
  • Compact design
Share your fluid process control challenges with application specialists, combining your process knowledge with their product expertise to develop effective solutions.

Friday, April 1, 2016

Video Demonstration of Weir Diaphragm Valve Operation

industrial diaphragm valve sectional view for process control
GEMU 620 Industrial Diaphragm Valve
Diaphragm valves comprise one of many different process control valve designs, each with specific attributes making them better suited for certain applications. Selecting the right valve type for an application is a critical early step toward successful control implementation.

Familiarity and understanding of how a particular valve type functions is necessary when equipping a fluid control system. Here are some considerations for valve operation that come into play.

  • Media Compatibility:
    Industrial process control applications cover an immense range of viscosity, velocity, solids content, and other physical media characteristics that may, or may not, be acceptably addressed by some valve types.
  • Cycle Frequency:
    Some valve types are more suitable for a high frequency of on/off cycles, others are better suited to slower rates.
  • Compatibility With Sanitary or Similar Operations:
    Some industries have requirements for special cleaning, sanitizing, or sterilizing of the process flow path. A valve design that does not trap the media within the valve body and allows for full exposure of the fluid path to whatever cleaning agent is applied has certain advantages for these applications. Some cleaning operations also require a full bore or straight through flow path to allow for proper cleaning.
  • Operating Speed:
    Different valve types may have varying capabilities to provide rapid change of valve position. Valve operating speed must be compatible with process requirements that may call for either rapid or slow opening or closing.
  • Throttling Ability:
    Each valve type, through the characteristics of its closure mechanism, offers comparatively different capacity for regulate fluid flow across an extended range between completely closed and fully open.
  • Space Requirements:
    Different valve trim arrangements can predicate how much installation space a valve may require for proper operation and maintenance. For example, a valve with a rising stem will generally require more clearance than a similar capacity valve with a rotating stem.
Industrial process control diaphragm valve Gemu
GEMU Model 620 Industrial Diaphragm Valve
Certainly, there are more aspects of valve operation that will be taken into account in the selection process. 

Diaphragm valves defend their niche of applications with their ability to:
  • Provide on/off or throttling service
  • Eliminate stem leakage
  • Provide bubble tight service
  • Eliminate pockets that may trap media
  • Isolate valve mechanism from media
  • Prevent contamination of media by valve parts or operation
Below is a short video that provides an animated look inside a weir diaphragm valve. The video provides a clear illustration of how the fluid flows through the valve and how the valve controls flow. There are variants of the diaphragm valve that do not use a weir, providing a straight through or full bore flow path. Their operation is similar.
Watch the video. It's short and to the point. Get the help you need solving your process control valve challenges from the seasoned experts at Mountain States Engineering.
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Monday, September 7, 2015

When is a Diaphragm Valve Your Best Choice?

Gemu Industrial Diaphragm Valve Metal Body Hand Operated
Hand Operated Metal Body Diaphragm Valve
Courtesy Gemu
Industrial process control, as a field of endeavor, covers an incredibly broad range of applications, all highly specialized in their own way. The control and handling of fluids is a prevalent activity in process control, leading to a wide variety of valves from which to choose for your application. Figuring out which flow control valve will best meet the needs of a particular application requires a detailed assessment of the physical elements to which the valve will be exposed, and under what conditions it will need to operate. In other words, know your process fluid, know your operating environment. A solid understanding of your process will make valve selection a simpler task, since there will likely be a small segment of your requirements able to be fulfilled by only one or two valve types.

When referring to valve types, common terminology generally describes the means utilized to control the flow. Some prevalent valve types, though certainly not an exhaustive list, include ball, plug, butterfly, diaphragm, gate, needle, and globe. Each of these basic designs have characteristics that make them more suitable than others for certain application conditions. Let's look at diaphragm valves.

A diaphragm valve controls fluid flow through the movement of a flexible membrane, unsurprisingly called a diaphragm. Numerous means can be employed to apply force to the diaphragm and a seal is created when the membrane compresses against a targeted portion of the valve body. A prominent feature of this valve type is the isolation, by the diaphragm, of the valve operation mechanism from the fluid. Two general body styles are available, referred to as weir and straight through. The weir design requires less extensive movement of the diaphragm than the straight through type, resulting in a longer expected life for the diaphragm. The straight through style, when open, provides little obstruction to the fluid flow and may be more suitable for some media.

Some diaphragm valve characteristics that might prove advantageous:

Pneumatically Operated Diaphram Valve, Plastic Body
Pneumatically Operated Diaphram
Valve, Plastic Body
Courtesy Gemu

  • Isolation of the valve operating mechanism from the fluid.
  • Design is easier to sanitize or sterilize in place than other valve types.
  • Throttling or shutoff service. Throttling generally limited to weir type.
  • Fast operation with powered actuators on weir type.
  • Valves can be lined with materials suitable for abrasive, corrosive, high purity, or other media.
  • Diaphragms available in wide variety of materials to suit application.
  • Leak tight shutoff.
  • Valves can be serviced in-line.
  • Suitable for many high purity applications with proper lining and membrane materials.

Diaphragm valve limitations that may be significant to your application:

  • Limited operating pressure range, when compared to many other valve types.
  • Flexing of diaphragm during operation limits usable life of the membrane and creates maintenance event.
  • Temperature range is limited to that of the membrane and liner material.
  • Range of available sizes is generally less than other valve types.
  • Manual operation is generally slow, requiring multiple turns of a handwheel.
Consider your process environment, consider your process fluid, consider if a diaphragm valve will provide the performance you need. I always recommend taking the time to discuss your application with a valve specialist. Their extensive knowledge base and application experience will enhance your solo valve selection performance. 




Friday, July 25, 2014

The Virtues of Angle Seat Valves

Gemu angle seat valve
GEMU Angle Seat Valve
“Angle valves” or “angle seat valves” are a family of on-off and control valves that have utilize a “Y” pattern body style, and a linear action to raise the disk from the seat to open and close the valve. By positioning the seat on an angle, the piston is pulled out of the flow path clearing the way for maximum flow. Angle valve provides tight shutoff, high cycle rate capability and very long service life. Here are other design features that make an angle valve a top performer: