Valve Magazine

Thu06202013

Last updateWed, 19 Jun 2013 1pm

Back You are here: Home Web Only Categories Technical

Technical

Noise from Cavitation: Bad for Control Valves, Bad for Equipment

noise from cavitation 1Just as sound can have negative effects on the human body, certain frequencies can play havoc on industrial equipment. When control valves are not selected appropriately, there is an increased risk for cavitation, which causes high noise and vibration levels, resulting in very rapid damage to the valve's internals and/or the downstream piping. In addition, high noise levels usually cause vibration that can damage piping, instruments and other equipment.

Modular Gas Valves: An Insiders’ Guide to Technology Breakthroughs

Burner FlamesThe main line of defense in combustion devices such as burners and boilers is fuel gas shutoff valves. They are key to safe operation of equipment for nonresidential comfort heating, commercial and industrial heating, and power and steam generation applications.

While conventional modular gas valves are popular and effective, the latest gener-ation of valves has seen dramatic improvements in design. Recent technological advance¬ments offer breakthrough features and benefits. These include higher flows, more compact footprints, and greater modularity and flexibility for downsizing fuel train components. They also include broad¬er temperature ranges, higher close-off pressures, more immediate availability and reduced costs of ownership.

In Line Weld Repairs of Valve Defects

Valve Repair Activities per ASME Section I & B31.1

Photo 1 WEBSIZEIf you have valves in your plant manufactured from F-91 or C12A material you may have problems and need repair services. In a 2-year period at our valve service company, a number of valuable observations were made about the cause of repairs necessitated by defects or operation, and the most effective solutions.

Third-Generation Valve Diagnostics, The Future of Predictive Maintenance

Figure 1The ability to prevent unexpected shutdowns and maintain control valve performance is directly linked to profitability. The ARC Advisory Group estimates that the average cost of plant downtime is $12,500 per hour with some plants. For some, of course, that rate is significantly higher, running upwards of $1 million per day of downtime.

Offshore High Pressure Relief Valve

Riser PipesOil wells drilled in deep waters typically face many difficulties with pressure, especially as the wells are placed on the bottom of the ocean floor. Oil and gas recovered from this depth can see pressures ranging 5,000 PSIG to 30,000 PSIG and possibly higher when flowing out of the well into the riser pipes. This is where many of the problems begin, and is the inspiration for development of valve technology that can withstand these extremely high pressures.

Criticality of Torque and Load in Bolted Joints

bolting headline“No matter how big and complex the machinery gets," said John Gans during his presentation at the November 2012 Valve Repair Council Repair Meeting & Exhibition in Houston, "at its heart, holding everything together, is the humble little bolt."

Dr. Gans repeatedly stressed the importance of having well-trained personnel conducting the critical function of bolting, and provided a comprehensive overview of material normally provided in a full one-day course.

Installed Gain and Control Valve Selection

Monsen headshot 330pxJon F. Monsen, Ph.D., P.E., is a control valve technology specialist, with more than 30 years' experience. He has lectured nationally and internationally on the subjects of control valve application and sizing, and is the author of the chapter on "Computerized Control Valve Sizing" in the ISA Practical Guides book on Control Valves.

What Makes Up a Servo Valve Feedback Mechanism is Mission Critical

ColorWheelfigure1To maximize machine operation and business results, engineers ought to consider more than how a servo valve performs with regard to flow/pressure gain, frequency response, and precision. The servo valve, in part, consists of a torque motor, flapper, spool and feedback mechanism. The feedback mechanism can last well above 1 billion cycles. But this lifespan is only achievable with the right selection of materials, manufacturing techniques and mechanical designs.

Measuring Stem Nut Wear Using the SNAP Process

snap testing a 15-foot sluice gate valve stem nut

A motor-operated valve (MOV) stem nut typically is made of a bronze alloy material. During a period of time, stem nut threads wear from opening and closing the valve. Since the valve stem is made of stainless or carbon steel, thread wear typically occurs on stem nut threads.

Ready for Low-E Valve Technology?

walter-moquin-headshot

With an estimated 60% of fugitive emissions attributed to valves it is easy to see EPA’s attention is on valve emissions reduction. Traditionally valve stem leakage was a visible event. Improvements in packing materials and design lead to non-visibly leaking valves.

In today’s world, government regulations drive measurement of valve leakage to the molecular level in parts per million (ppm). These extremely low vaporous emissions required packing manufacturers to evaluate their product performance to the latest EPA standards for Low E Valve Packing Technology.

 

Ball Valve Coatings: Different Coats for Different Apps

coatings-ball-valveCoatings protect valves and actuators against wear, erosion, chemical attack and other forces that threaten their durability and effectiveness. But because they are faced with such a diversity of challenges, there are a broad number of differences in the types of coatings used. The coatings used for ball valves have their own set of characteristics that differ in many cases from other types of valves.

Sponsored Products

 

Valve Magazine Digital Edition

13 SPR CVR 160x214Inside the Spring 2013 issue…

• Valves in the World of Water
• The Breadth of Plastic Valves
• Aerodynamic Noise
• Manual Actuation

CLICK HERE TO REQUEST YOUR
DIGITAL EDITION PREVIEW EMAIL