Eccentric Rotary Plug Control Valve

rotary eccentric plug industrial control valve with actuator
The MaxFlo 4 eccentric rotary plug control valve
Image courtesy of Flowserve Valtek
There is a seemingly limitless array of industrial control valves, each targeted for a range of fluid applications and fortified with materials and design features specifically suited for meeting the challenges of that application range.

Flowserve, under their Valtek brand, developed a control valve that combines a number of useful design features. The MaxFlo 4 is an eccentric rotary plug valve intended for fluid control operations. The valve has some attractive design features.

  • There is no shaft extending through the flow path, leaving flow unobstructed when the valve is fully open (see the illustration in the document included below).
  • Valve trim provides tight bi-directional shutoff.
  • Metal or soft seat construction is available to accommodate a wide range of applications.
  • A variant provides flange to flange dimensions that allow the MaxFlo 4 to drop in as a replacement for standard size globe valves.
  • High Cv rating may enable use of a smaller valve, when compared to other designs.
  • Precise position control is delivered by the shaft form and plug mounting.
  • Double offset eccentric plug eliminates sliding of plug across sealing surfaces, reducing wear and required seal maintenance.
More detailed information is provided in the document provided below. There is a revealing cutaway illustration showing the mounting and movement path of the plug. Share your industrial process control valve requirements and challenges with an application specialist to get the best match of control valve to application.

Ultrasonic Flow Measurement Overview

ultrasonic flowmeter for custody transfer
One of several versions of ultrasonic flowmeter suitable
for custody transfer operations.
Courtesy Krohne
Ultrasonic flow meters measure, via sound waves inaudible to humans, the velocity of fluid flowing through a conduit. The conduit can be a recognizable closed piping run, or open channels, flumes, or chutes. The technology is predominantly applied to liquids and gases. 

There are three types of ultrasonic flow meters, differentiated by their means of measurement. An open channel flow meter derives liquid depth by computing geometrical distance, combining it with a velocity measurement and known dimensional properties of a flume or other channel. A Doppler shift flow meter reflects ultrasonic energy off sonically reflective materials and measures the frequency shift between emission and reflection to derive a fluid velocity measurement. The contrapropogating transit-time flow meter, more recognizably, the transmission flow meter. The transmission flow meter has two versions: the in-line and the clamp-on. The in-line configuration is intrusive, with flow meter hardware extending into and exposed to the measured media. A clamp-on style ultrasonic flow meter resides on the outside of the pipe, emitting and receiving the ultrasonic pulses through the pipe wall. These process measurement tools, using ultrasound technology, have the ability to measure fluid velocity and calculate volumetric, mass, and totalized flow. The use of ultrasonic flow measurement is prevalent in the oil and gas, nuclear, wastewater, pharmaceutical, and food and beverage industries. It is also employed in energy management systems as a means to measure energy demand. 

For intrusive flow meters, sensors are fitted opposite one another and alternate bouncing ultrasonic signals back and forth in the pipe, in an almost tennis-like format. In an elementary explanation, by increasing the number of sensors, engineers are able to decipher flow proportions through calculations of velocity between sensory transmissions; thereby, the flow volume can be computed. 

For externally mounted flow meters, a clamp-on device affixes the flow meter measurement elements to the pipe. One special characteristic of clamp-on flow meters is the ability to transmit ultrasonic signals through piping up to four meters in diameter, making them suitable for application in very large systems such as those found in hydroelectric or wastewater installations. The clamp-on arrangement also facilitates addition of a flow measurement point to an existing system without process interruption. 

The technology is pervasive in the processing industries, having its particular niche of applications where it excels. Proper installation is a key element in producing reliable and consistent results. Ultrasonic energy flow technology is used for custody transfer of natural gases and petroleum liquids. Custody transfer usually entails following industry, national, and government standards and regulations. Other popular applications include compressed air system monitoring and energy usage metering. 

Ultrasonic flow meters, with no moving parts, are comparatively low maintenance and self-diagnosing. Temperature and pressure measurements are needed to calculate mass flow of gases. When measuring liquid mass flow in pipes, it is generally necessary for the pipe cross section to be media filled in order to obtain reliable results. 

Whatever your flow measurement challenge, share it with a process measurement specialist. Combine your process knowledge with their product application expertise to develop effective solutions.

Medium Voltage Drives With Reduced Footprint

variable frequency drive VFD medium voltage
Medium voltage variable frequency drive
Courtesy Siemens
Floor space, a resource most facilities managers dole out sparingly. There seldom seems to be enough for all the equipment and operations that comprise a modern industrial operation.

Siemens, globally recognized leader in the design and manufacture of variable frequency drives, offers its latest version of the Perfect Harmony GH180 variable frequency drive to reduce the required footprint by up to one third. The drive includes a transformer cabinet, cell cabinet, and cooling cabinet. Programming has been simplified and reduced, along with component count and required connections. A number of other enhancements increase reliability and reduce the need for maintenance. The units are available for medium voltage applications and come in air-cooled and water-cooled variants.

Share your motor drive requirements with product application specialists, combining your first hand facility knowledge and experience with their product application expertise to develop effective solutions.

Open Channel Flow Measurement Combines Laser and Ultrasonic Technologies

Combining Doppler laser velocity measurement with ultrasonic level measurement enables the Teledyne ISCO LaserFlow™ sensor to provide reliable and accurate flow measurement in open channel applications.

Ultrasonic technology is used to determine the depth of the liquid stream and identify a sub-surface point at which to measure velocity. After focusing the sensor's laser on the target, Doppler shift in the returned light is used to calculate the flow velocity. A flow computer combines the information to produce useful flow data.

The video provides detail on the application and features of the LaserFlow™ sensor. Share your flow measurement requirements and challenges with instrumentation specialists, combining your own process knowledge and experience with their product application expertise to develop effective solutions.