Showing posts with label engineered valves. Show all posts
Showing posts with label engineered valves. Show all posts

Wednesday, February 7, 2018

Plug Valves - Right For Your Application?

industrial plug valve with manual operating handle
Plug valves incorporate design features making them
a positive choice for many fluid process applications.
Image courtesy Fluoroseal, Inc.
There are common components to be found on almost every process system that involves fluid control. Regardless of the operation's scale, pumps, piping, tanks and valves are likely to be part of the system.

Valves, of which there are many types, provide control over the flow rate, direction and routing of fluids in a processing operation. Flow can be started, stopped or modulated between zero and full rate using a properly sized and configured valve. Some valves enable media flow to be diverted to a selection of outlets, in lieu of a single inlet and outlet pair. Specialized valves regulate inlet or outlet pressure, or prevent fluid flow from going in an undesirable direction. All of these capabilities are packaged into differing valve product offerings that present a very large selection array to a process designer or engineer.

Industrial flow control valve types are generally classified according to the structure or arrangement contained within the valve body that provides obstruction to fluid flow. Some of the common types are ball, butterfly, gate, globe, and plug. Surely, there are more valve types, and this article is not intended to list them all. Some of our previous blogs have discussed selection considerations for gate, ball and butterfly valves. This article will focus on one of the oldest valve types, the plug valve.

Plug valves, like ball and butterfly valves, span from fully open to fully closed positions with a shaft rotation of 90 degrees. The “plug” in a plug valve is installed in the flow path within the valve body and rotated by means of a stem or shaft extending to the exterior of the body. Plugs are often tapered toward the bottom and are fitted to a seating surface in the valve body cavity that prevents fluid from bypassing the plug. An opening through the plug, the port, can be shaped to provide particular flow characteristics. There are numerous variants of the basic plug valve which may make it suitable for particular applications. One common variant is the lined or sleeved plug valve, with an insert or interior lining of material that creates an isolating barrier between the valve body and the media. This allows use of less expensive materials for the body construction that may be otherwise subject to corrosion by exposure to aggressive media.

Positive attributes of plug valves.

  • 90 degree rotation from open to closed provides fast operation.
  • With proper configuration, can be well suited for frequent operation.
  • Availability of corrosion resistant liner may provide comparative cost savings because valve body can be constructed of less expensive material.
  • Design is simple and employs a low parts count.
  • Valve can be serviced in place.
  • Generally, low resistance to flow when fully open.
  • Reliable leak-tight service due to tapered plug wedging action, replaceable sleeve, and injection of lubricant in some variants.

Potential issues of concern.

  • Higher friction in the plug closure mechanism may require comparatively higher operating torque than other valve types.
  • Without a specially designed plug, generally not well suited for throttling applications.
  • Rapid shutoff delivered by plug design may not be suitable for some applications where hammering may occur.

Share your fluid control application challenges with a valve and automation specialist. Leverage your own knowledge and experience with their product application expertise to develop an effective solution.

Tuesday, July 21, 2015

Selecting the Right Valve Type - Plug Valves

Valves are the primary fluid flow control device employed in the industrial process control arena. The widely varied applications and requirements have led to an almost daunting array of vendors. valves and options from which to choose. For your particular project or application, the selection candidate pool can be shrunk down to a manageable size if you first select the type of valve that will best suit your needs.

industrial plug valve internal part
The "Plug" in a Plug Valve
Courtesy Fluoroseal Inc.
Valves are generally used to start, stop, redirect, or throttle (control at some intermediate level) the flow of a fluid. They may also be tasked with preventing fluid flow from going in an undesirable direction or regulating pressure. Industrial flow control valve types are generally classified according to the structure or arrangement within the valve body that provides the obstruction to fluid flow. Some of the common types are ball, butterfly, gate, globe, and plug. Surely there are more valve types, and this article is not intended to list them all. Some of our previous blogs have discussed selection considerations for ball, butterfly, and gate valves. Let’s look at one of the oldest valve types, the plug valve.

Plug valves are similar to ball and butterfly valves, with their rotational movement of 90 degrees from the fully open to the closed positions. The “plug” in a plug valve is installed in the flow path within the valve body and rotated by means of a stem extending to the exterior of the body. Plugs are often tapered toward the bottom and are fitted to a seating surface in the valve body cavity. An opening through the plug, the port, can be shaped to provide particular flow characteristics. There are numerous variants of the basic plug valve which may make it suitable for particular applications. One common variant is the lined plug valve, with an interior lining of material suited to provide a measure of corrosion resistance for special media applications.

industrial plug valve
Industrial Plug Valve With Manual Operation Handle
Courtesy DHV Industires
What are the general positives for plug valve application?

  • 90 degree rotation from open to closed provides fast operation.
  • With proper configuration, can be well suited for frequent operation.
  • Availability of corrosion resistant liner may provide comparative cost savings because valve body can be constructed of less expensive material.
  • Design is simple and employs a low parts count.
  • Valve can be serviced in place.
  • Generally, low resistance to flow when fully open.
  • Reliable leak-tight service due to tapered plug wedging action, replaceable sleeve, and injection of lubricant in some variants.

What are some potential negatives for plug valves?

  • Higher friction in the closure mechanism may require comparatively higher operating torque than other valve types.
  • Generally not well suited for throttling applications without special design modifications.
  • Rapid shutoff may not be suitable for some applications where hammering may occur.

As part of your own assessment and selection process, share your application requirements and concerns with an experienced sales engineer. Their product knowledge and application experience can provide the additional input needed to make the best choice for your project.

Friday, June 26, 2015

Selecting The Right Valve Type - Ball Valves

Applications that can be characterized as industrial fluid handling or process control are vast in number and variety, each being highly specialized and customized to specific circumstances. It’s no surprise that, given the array of potential application conditions, there are countless different valve arrangements, types, and technologies to choose from.
Industrial Ball Valve
Large Industrial Ball Valve
Courtesy HS Valve Co.
Ball valves, like many valve types, are named for their closure mechanism. A spherical shaped element is placed in the fluid flow path, with the ability to rotate its position around an axis. The axis is a shaft or other device that connects to an actuator on the exterior of the valve and flow path. The actuator can be a simple handle or an element of a valve automation system. The “ball” in the ball valve has an opening through its center, usually round to mimic the shape of the connected pipe. As the ball is rotated, the opening aligns with the inlet an outlet of the valve body, allowing fluid to pass. A counter-rotation that aligns the opening with the sides of the valve body, away from the flow path, stops the fluid flow. So, compared with other valve technologies, when would a ball valve be a preferred application choice? Here are some points to consider.

Application advantages of ball valves:

  • Leak-proof service
  • Well suited for processes requiring only full flow or no flow operation.
  • Rapid open and close action, requiring only 90 degrees of rotation from fully open to fully closed.
  • Comparatively light weight and small size.
  • Wide range of construction material options for body, ball, and seals make them suitable for many applications.
  • Require only moderate force to control valve position.
  • Flow path opening in the ball will often be “full port”, providing same cross section as the connected pipe and adding very little restriction or pressure drop to the flow.
  • Low maintenance, with no lubrication required.

What considerations might be cause to consider a different valve type?

  • There can be some residual fluid trapped in the valve when it closes.The trapped fluid will be released when the valve is opened. Consider what impact, if any, this may have on your process.
  • Balls valves are generally not suited for throttling applications. When partially open, the seals that surround the ball are exposed to the flow velocity and can deteriorate quickly.
  • Valve seals are usually elastomeric materials. Verify seal materials are compatible with the fluid type, character and operating temperature.

These comments are general in nature and there are some specialized ball valve designs that have overcome some of the general disadvantages noted here. Have a conversation with a valve specialist about your application and benefit from their experience and knowledge.

Thursday, June 11, 2015

The Often Undervalued Sales Engineer

Call a sales engineer
Sales engineers add value.

Process and control equipment is most often sold with the support of sales engineers working for the local distributor or representative. Realizing what they have to contribute, and taking advantage of this available talent, will help you save time, cost, and also assist in achieving a better outcome for the project.

Consider these contributions:

Product Knowledge: Sales engineers, by the nature of their job, are current on new products, their capabilities and their proper application. Unlike information available on the Web, sales engineers get advanced notice of product obsolescence and replacement. Also, because they call and work with so many different types of companies, sales engineers are a wealth of tacit knowledge that they readily share  with their customers.

Experience: As a project engineer, you may be treading on fresh ground regarding some aspects of your current assignment. You may not have a full grasp on how to handle part of a control loop. Call in the local sales person - there can be real benefit in connecting to a source with past exposure to your current issue.

Access: Through a technical sales engineer, you may be able to look “behind the scenes” with a particular manufacturer and garner important information not publicly available. Sales reps deal with people, and make it his/her business to know what’s going on with products, companies, and industries.

Of course, sales engineers will be biased. Any solutions proposed are likely to be based upon the products sold by the representative. But the best sales people will share the virtues of their products openly and honestly, and even admit when they don’t have the right product. This is where the discussion, consideration and evaluation of several solutions become part of achieving the best project outcome.

As an engineer who designs or manufactures a product or process, it's highly recommended you develop a professional, mutually beneficial relationship with a technical sales expert. Look at a relationship with local sales engineer as symbiotic. Their success, and your success, go hand-in-hand.

Monday, May 18, 2015

And Now for A Little Shameless Self Promotion ...

A little shameless self promotion to spread the word of what lines Mountain States Engineering and Controls carries should anyone out there need assistance.


MSEC, Inc. is a Manufacturer's Representative & Distributor of process equipment and controls headquartered in Lakewood, Colorado since 1978.

We serve the markets of Colorado, New Mexico, Wyoming, Montana, Utah, Nevada, Idaho, and the western Dakotas.

Saturday, May 31, 2014

Always Looking for Ways to Add Value and Help Customers Solve Industrial Process Control Challenges

We opened our doors in 1978 with the mission of creating the most technically competent and application savvy industrial process control rep in the Mountain States. Headquartered in Lakewood, Colorado, MSEC established itself as a premier Manufacturer's Representative and Distributor of process equipment, industrial controls, engineered valves, heat exchangers and cooling towers. Serving the markets of Colorado, Wyoming, Montana, Utah, Nevada, Southern Idaho, Western Dakotas and the Panhandle of Nebraska, we earned a reputation for outstanding customer service. Now, with the reach and convenience of the Internet, we'll use this blog as another way to provide value to our customers - both existing and prospective.

We plan on sharing years of experience and knowledge here. Steam management experiences, process control application case histories, new industrial control products, automated valve packages and interesting jobs we've done. We hope this will be a place where information can be exchanged. If you like what you see, please tell others in your industry about us.