VALVE SPECIFYING FOR BEGINNERS

September 26th, 2007

VALVE MANUFACTURERS AND DISTRIBUTORS OFFER A WEALTH OF TECHNICAL INFORMATION AND APPLICATION EXPERIENCE THAT NOVICE SPECIFIERS CAN USE TO BROADEN THEIR ENGINEERING KNOWLEDGE AND JUDGMENT.

BY PATRICK A. TOENSMEIER

Few jobs are more critical to the development of a process engineer’s skills than specifying valves and actuators. Working as part of a team and dealing with a range of application needs, from performance requirements to code standards, installation schedules and aftermarket service, specifying provides young engineers with a wealth of on-the-job training and lays the foundation for building a store of problem-solving knowledge.

Yet this introduction to the hands-on world of process engineering is not without challenges, many of which reflect recent trends within the industry. For example:

The layoffs, corporate consolidations and business slowdowns of the 1990s that reduced staffing levels in the process industry, left young specifiers with less access to older colleagues who once mentored and shared their expertise with them.

Specifiers must increasingly acknowledge the bottom-line concerns of accounting departments and deal with pressure to procure products based on installation quotes rather than more expensive life-cycle cost projections.

There is a tendency among novice specifiers to bundle commodity and engineered valves together when seeking quotes, a practice that makes it difficult to get comprehensive information about products for severe-service applications.

Many young engineers are attracted to what one observer terms “the glitzy stuff”—distributive controls, computer systems and other high-tech components of an installation—rather than the actual hardware on which applications are based, leaving a significant gap in their understanding of flow-control technology.

Poor Specification Choices Are Costly
With business in the process industry on a solid upturn, the ability to produce experienced valve and actuator specifiers is critical to the growth and profitability of engineering companies and their customers. Poor specification choices may result in problems ranging from costly shutdowns of process lines to catastrophic plant failures. Among the sources engineers tap for guidance and expertise in specification are the suppliers of valves and actuators, both manufacturers and distributors, who report playing a more active role in this area.

“We are much more involved with the specification of valves than we used to be,” says Morris Lavergne Jr., Houston contractor sales manager for the Masoneilan business unit of Dresser Consolidated Industries. “When we first began doing this it was a value-added benefit. Nowadays, it’s a given.”

Lavergne attributes the growing involvement in specification by companies like Masoneilan, which supplies control valves, to a knowledge gap in engineering firms that stems from the downturn of the late 1990s, when experienced engineers left the industry and engineering graduates looked to other businesses for job opportunities.

When Lavergne entered the process industry 30 years ago, a project team of 10 had at least several engineers who knew a great deal about the products they were specifying. “Most specifiers now only have a handful of guys [company-wide] who know about control valves,” he remarks. “We have resident engineers who go on-site and work with our customers on our products, which they know inside and out. As a result, our customers don’t really need that level of expertise.”

“There’s a big age gap between the experienced engineers who are 50 and over and the younger engineers,” remarks George Milleret, president of Myers-Aubrey Co., a distributor in Tulsa, OK. “There are new hires, but few people in the age group between 30 and 50.” This loss of “tribal knowledge,” as Bruce Broxterman calls it, not only affects a company’s ability to specify valves for current applications, but has an impact on maintenance work at older installations. Broxterman, president of the Valve Group of Richards Industries, Cincinnati, OH, says that in these facilities, “There are quirks and unusual aspects of the plant that older engineers understood and knew how to handle. This information used to be passed along, but with all the changes in the industry, laying people off and transitioning ownership, it’s not always there anymore.”

One manufacturer in particular sees how the loss of institutional knowledge at many companies affects the abilities of young engineers. “The simple mating of flanges has suddenly become an issue,” says Ed Ross, marketing director for instrumentation products at Tyco Valves, Baytown, TX. “The experience of the engineer is not there when it comes to knowing how to put two flanges together correctly without having an issue with the gasket in between. You’d think it’s pretty simple, but we’ve had to sit down and write detailed instructions for that.”

Relationships Are Key
Manufacturers and distributors say that in many cases the best way for new specifiers to acquire practical knowledge for their jobs is to develop long-term relationships with them. This might appear self-serving, but vendors offer a wealth of technical information and application experience that specifiers can use to broaden their engineering knowledge and judgment. Manufacturers and distributors also say they want specifiers to make the right product choices, even if it means that in some cases they lose business to competitors.

“As a vendor we have a responsibility to educate [specifiers] and help them review their specifications to be sure they not only meet their process needs, but the codes and standards they have to comply with,” says Charlie Weiland, president and general manager of Chalmers & Kubeck-South, Watkinsville, GA. Weiland says his company has helped engineers specify lower-cost valves simply by learning the details of what an installation requires. “We say to the specifier,

‘Let’s talk about the job first and be sure we understand what you’re trying to accomplish, and that the valve you’re asking for is what you should have for that application from a metallurgy standpoint, a capacity standpoint, and a codes and standards standpoint.’ In some cases we might not get the order,” Weiland notes, “but at least we’ve done the right thing” in letting the engineer understand that the valve he or she was asking for was not the correct valve.

It’s essential that specifiers discuss projects with vendors as soon as possible, especially when they are building relationships with these companies. “It would probably be better to speak with a distributor first,” suggests Ross. If the distributor is experienced in the product a specifier needs, the distributor can provide direction, and “if the product required is unique or if the specifier needs additional information, the manufacturer can be involved.”

“Project specifications can be the easiest thing that you do or the hardest, depending on your reference material and whether or not you get any assistance from vendors, which is absolutely critical,” says John Faulkinberry, Houston contractor sales manager for Dresser Consolidated Industries.

A common problem that vendors note when discussing projects with new specifiers is a lack of detail about applications. Specifiers usually don’t present all the information a supplier needs to assist in the product selection process. To a large degree this is due to their inexperience, and is an important reason why face-toface meetings and relationships are vital to the learning curve.

“The biggest thing we have trouble with is getting complete application details,” says Broxterman. “That entails a variety of information: the media that flows through the valves, inlet-outlet pressure, flow rate, and even where in a pipe a valve will be installed.” The more specifiers can tell valve makers about what they want the valve to do, “the better we can do our job,” he adds.

Ross similarly advises that a specifier should research the requirements of an application prior to meeting with a supplier. The specifier needs to look at what the process conditions are, what materials are most suitable for that process, and what codes and standards will apply to the specification. Once this information is gathered, the specifier can determine what needs to be accomplished with the valve, and what type of valve he or she needs to buy, says Ross.

Milleret recommends that in addition to technical data, young specifiers must know how to accurately express themselves in language suppliers understand. The specifier “can’t have a conversation without knowing industry terminology,” Milleret says. This not only involves accurately describing the valves a specifier is thinking of procuring, but being conversant with their performance characteristics, metallurgy properties and relevant ASME codes.

Commodity vs. Engineered
A related issue is the tendency of inexperienced specifiers to bundle different types of valves together in an effort to streamline the bidding and supply process. “The term ‘valves’ covers a very broad category,” says Weiland. “One of the things a specifer has to be cautious about is not to group engineered products with commodity valves.” The problem is that by putting different valves in one broad category, specifiers create barriers to information that would help them make smarter choices regarding performance, installation and cost.

“When they do that, specifiers really put a gap between themselves, the manufacturer and people with the product knowledge to protect against [a valve selection] not meeting a specification or a code and standard,” Weiland notes.

“The potential for a valve to be installed in the wrong application because an engineer with specialty knowledge has been removed from the specification process increases considerably.”

According to many vendors, part of this comes from efforts by financial people to reduce procurement costs, a worthy effort, to be sure, but one that can produce unintended consequences such as early replacement of a valve or the failure of a process line. The best way to deal with this attitude, says Faulkinberry, is to explain its potential ramifications to the specifier, who needs to understand that a buying decision has a lot of issues to it. “There are upfront costs and long-term ownership costs. The entire cost of the product they’re purchasing can’t be valued in the initial quotation stage.”

“The procurement guys are doing what they’re supposed to do—drive down costs,” says Weiland. “But they have to be careful not to group products under an umbrella where they don’t belong, like engineered valves with commodity valves.” The older engineers knew what worked, whereas the younger engineers may yield more readily to the influence of the procurement process, he suggests.

Faulkinberry adds that the total cost of a project should be one of the first points a manufacturer or distributor explains to a specifier, even if there is initial resistance to learning about higherpriced valves. “It is my job as a technical salesperson to justify the cost that my products warrant,” he remarks.

Shopping the Net? Buyer Beware
Cost considerations may make some specifiers look to new areas as potential sources of supply. One such source is the Internet, a purchasing option that draws mixed reactions from distributors and manufacturers, though most discount the impact of online valve purchases.

“When you get on the Internet you really don’t know the reputation of [the vendors] you are dealing with,” notes Weiland. “There are a lot of pitfalls out there, and the term ‘buyer beware’ is very true, even in our industry.”

“The Internet might be fine for buying commodity products,” says Broxterman, “but if you’re buying engineered products, it’s pretty tough. It can be done, but all that application knowledge won’t be there.”

“It would be very difficult to make an online purchase of a control valve,” asserts Lavergne. “We’ve had many customers attempt to do that without
any success.”

“I don’t think our industry is Webbased at all,” says Milleret. “We are a competitive industry and a specifier can get a better price, but probably not on the Web.”

Ross suggests, “There’s nothing wrong with buying on the Web, but engineers should do their research to make sure they’re buying an apples-toapples product.”

Another alternative supply source is foreign manufacturers with operations in North America. Manufacturers and distributors advise against going this route unless the company convincingly demonstrates it has locally available products, ample inventory, technical assistance and extensive field-support capabilities.

“You have to look at the total lifecycle of a valve,” says Weiland. “These products require periodic servicing and may entail multiple repairs. The availability of replacement parts, technology, customer support and a long-term relationship should be of prime concern to a young engineer.”

Make Time for Education
Vendors actively promote educational opportunities for specifiers beyond those related to specific applications. Programs are designed to increase the awareness of young engineers about different types of valves and actuators, how they are used in installations and what makes them fail. The goal, the companies say, is to familiarize specifiers with the nuts-andbolts details of valves, focusing for the most part on generic designs and capabilities, and minimizing overt sales pitches for particular products.

One popular format is the “lunch-andlearn” presentation, which almost every distributor and manufacturer sponsors throughout the year in various areas for any specifier who wants to attend.

Some companies balance this approach with more targeted audiences. Faulkinberry prefers to train a handful of select specifiers for several hours, making technical presentations that can be generic or product related based on the group.

Another option is to invite specifiers to a manufacturer’s factory where they not only receive technical presentations on valves and actuators, but see how they work in a lab under simulated operating conditions. Ross says a key feature of the factory seminars his company presents is demonstrating the results of incorrect piping, installation practices and valve specification.

“Showing them what actually happens when you do things badly sticks out in their minds.”

Despite all these efforts, most of the education process depends on specifiers’ willingness to make time to learn the details of their trade.

“The engineer can’t be afraid to invest time in face-to-face meetings,” says Broxterman. “Everyone is busy and tends to shy away from that dreaded sales call or lunch-and-learn, or whatever it happens to be that’s going to take time out of the day. But if specifiers see this as an investment in their knowledge or in vendor relationships, then it has a great deal of value for making them better engineers, and their companies better from an operations standpoint.”

Writer PATRICK A. TOENSMEIER, based in Hamden, CT, specializes in manufacturing and technology issues. His background includes covering the global plastics and tooling industry for 20 years and writing for a variety of industry and business publications.

Industry Association

September 26th, 2007

American National Standards Institute
Develops standards for valves, ANSI standards
              212.642.4900       
www.ansi.orgAmerican Petroleum Institute
Develops standards for Petroleum industry valves, API standards
              202.682.8000       
www.api.org

American Pipe Fittings Association
Represents manufacturers of fittings and couplings for our industry
              703.538.1786       

American Society of Mechanical Engineers
Develops standards for valves, ASME standards
              212.591.7000       
www.asme.org

American Supply Association
Represents manufacturers, wholesalers and distributors of plumbing valves
              312.464.0090       
www.asa.net

Fluid Control Institute
Represents similar companies as VMA and develops standards
              216.241.7333       
www.taol.com/fci

Fluid Sealing Association
Manufacturers of mechanical packings, sealings and gaskets
              610.971.4850       
www.fluidsealing.com

Hydraulic Institute
Pump manufacturers
              973.267.9700       
www.pumps.org

Industrial Distribution Association
Represents distributors of industrial products including valves
              404.266.3991       
www.ida-assoc.org

Manufacturers Standardization Society
Develops valve standards, MSS standards
              703.281.6613       
www.mss-hq.com

National Fluid Power Association
Manufacturers of hydraulic and pneumatic valves
              414.778.3344       
www.nfpa.com

Plumbing Manufacturers Institute
Manufacturers of plumbing valves
              847.884.9764       
www.pmihome.org

Electric Actuators

September 26th, 2007

The electric actuator has a motor drive that provides torque to operate a valve. Electric actuators are frequently used on multi-turn valves such as gate or globe valves. With the addition of a quarter-turn gearbox, they can be utilized on ball, plug, or other quarter-turn valves.

Hydraulic and Pneumatic Actuators

September 26th, 2007

The hydraulic and pneumatic actuators are often simple devices with a minimum of mechanical parts, used on linear or quarter-turn valves. Sufficient air or fluid pressure acts on a piston to provide thrust in a linear motion for gate or globe valves. Alternatively, the thrust may be mechanically converted to rotary motion to operate a quarter-turn valve. Most types of fluid power actuators can be supplied with fail-safe features to close or open a valve under emergency circumstances.

Manual Actuators

September 26th, 2007

A manual actuator employs levers, gears or wheels to facilitate movement; while an automatic actuator has an external power source to provide the force and motion to operate a valve remotely or automatically. Power actuators are a necessity on valves in pipelines located in remote areas: they are also used on valves that are frequently operated or throttled. Valves that are particularly large may be impossible or impractical to operate manually simply by the sheer horsepower requirements.

Some valves may be located in extremely hostile or toxic environments, which preclude manual operation. Additionally, as a safety feature, certain types of power actuators may be required to operate quickly, shutting down a valve in case of emergency.

SPECIALTY VALVES

September 26th, 2007

In addition to these standard valve products, many valve manufacturers produce custom-designed valves and actuators for specific applications. Valves are available in a broad spectrum of sizes and materials. Each design has its own advantages, and selection of the proper valve for particular application is critical. The factors generally considered in the selection of a valve include:
? The substance to be handles and the required flow rate.
? The requirement that the valve control and/or shut off the flow in the manner demanded by the service conditions.
? The ability of the valve to withstand the maximum working pressure and temperature.
? The ability of the valve to resist attack by corrosion or or erosion.
? Actuator requirements, if any.
? Maintenance and repair requirements.

CONTROL VALVES

September 26th, 2007

The Control Valve
The control valve is designed to ensure accurate proportioning control of flow. It automatically varies the rate of flow based on signals it receives from sensing devices in a continuous proces. Some valves are designed specifically as control valves. However, most types of valves can be used control valves, both linear and rotary motion, by the addition of power actuators, positioners and other accessories.

QUARTER TURN, OR ROTARY VALVES

September 26th, 2007

The Plug Valve
The plug valve is used primarily for on–off service and some throttling services. It controls flow by means of a cylindrical or tapered plug with a hole in the center that lines up with the flow path of the valve to permit flow. A quarter turn in either direction blocks the flow path.

The Ball Valve
The ball valve is similar in concept to the plug valve but uses a rotating ball with a hole through it that allows straight-through flow in the open position and shuts off flow when the ball is rotated 90 degrees to block the flow passage. It is used for on–off and throttling services.

The Butterfly Valve
The butterfly valve controls flow by using a circular disc or vane with its pivot axis at right angles to the direction of flow in the pipe. The butterfly valve is used both for on–off and throttling services.

MULTI-TURN VALVES OR LINEAR MOTION VALVES

September 26th, 2007

The Gate Valve
The gate valve is a general service valve used primarily for on–off, non-throttling service. The valve is closed by a flat face, vertical disc, or gate that slides down through the valve to block the flow.

The Globe Valve
The globe valve effects closure by a plug with a flat or convex bottom lowered onto a matching horizontal seat located in the center of the valve. Raising the plug opens the valve, allowing fluid flow. The globe valve is used for on–off service and handles throttling applications.

The Pinch Valve
The pinch valve is particularly suited for applications of slurries or liquids with large amounts of suspended solids. It seals by means of one or more flexible elements, such as a rubber tube, that can be pinched to shut off flow.

The Diaphragm Valve
The diaphragm valve closes by means of a flexible diaphragm attached to a compressor. When the compressor is lowered by the valve stem onto a weir, the diaphragm seals and cuts off flow. The diaphragm valve handles corrosive, erosive and dirty services.

The Needle Valve
The needles valve is a volume-control valve that restricts flow in small lines. The fluid going through the valve turns 90 degrees and passes through an orifice that is the seat for a rod with a cone-shaped tip. The Size of the orifice is changes by positioning the cone in relation to the seat.

WHAT IS A VALVE?

September 26th, 2007

A Valve is a product rarely noticed by the average person, yet it plays an important role in the quality of our life. Each time you turn on a water faucet, use your dishwasher, turn on a gas range, or step on the accelerator of your car, you operate a valve. Without modern valve systems, there would be no fresh pure water or automatic heat in your home. There would be no public utilities, and beyond wood and coal, almost no energy of any kind. Plastics would be unheard of, as would many inexpensive consumer products.By definition, a valve is a device that controls the flow of a fluid.Today’s valves can control, not only the flow, but also the rate, the volume, the pressure or the direction of liquids, gases, slurries or dry materials through a pipeline, chute or similar passageway. They can turn on and turn off, regulate, modulate or isolate.They can range in size from a fraction of an inch to as large as 30 feet in diameter and can vary in complexity from a simple brass valve available at the local hardware store to a precision-designed, highly sophisticated coolant system control valve, made of an exotic metal alloy, in a nuclear reactor.

Valves can control flow of all types, from the thinnest gas to highly corrosive chemicals, superheated steam, abrasive slurries, toxic gases and radio active materials. They can handle temperatures from cryogenic region to molten metal, and pressures from high vacuum to thousands of pounds per square inch.

The valve is one of the most basic and indispensable components of our modern technological society. It is essential to virtually all manufacturing processes and every energy production and supply system. Yet it is one of the oldest products known to man, with a history of thousands of years.

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