2 edition of Characteristic coefficients of butterfly valves. found in the catalog.
Characteristic coefficients of butterfly valves.
Sylva May Dushkes
|Contributions||American Society of Mechanical Engineers|
|The Physical Object|
|Pagination||26 leaves. diagrs., tables.|
|Number of Pages||26|
Friction Losses in Pipe Fittings Resistance Coefficient K (use in formula hf = Kv²/2g) Fitting LD Nominal Pipe Size ½ ¾ 1 1¼ 1½ 2 2½-3 4 6 For example, the diameters and forms of the valves installed in the two pipes are exactly the same, while the flow rate of the valves will vary greatly with different loss coefficients of the pipes. When the butterfly valve is at a medium opening, the opening shape formed by the front end of the valve body and the valve plate is centered on the.
A 4 inch high performance butterfly valve operating at around 70% open would also have a Cv of about Although both valves have the same flow capacity (CV), the graph of flow through the butterfly valve (red line on the left hand graph) looks quite different than the graph of flow through the globe valve. Butterfly valves are used to control flow in a pipe line. Rotating a disc within the valve body 90° opens or closes the flow passage. The butterfly valve can be operated with the position locking hand lever. Butterfly valves are mounted between two pipe flanges for easy installation and maintenance.
Shedid () investigated the reliability of the valve loss and torque coefficients in designing butterfly valves when the fluids were Al 2 O 3 -water nanofluids. Using numerical simulation, he. measured both coefficients at an an and They have done analysis on m size of butterfly valve. They made a process for different flow fluid at different angle with different surface roughness of disc of butterfly valve. Problem statement Weir-BDK is design maker and developer of Butterfly .
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Cv & Kv Fraction vs Angle Closure Curve Characteristic coefficients of butterfly valves. book. This graph shows the Cv or Kv valve fraction vs opening and closing angle of a butterfly valve: The full closure curve of a butterfly valve is then the above graph multiplied by the valve’s flow coefficient or factor.
4 Vb2 Engineering Data Book 1. Butterfly valves have lower valve recovery coefficients, Km, than globe valves. The value of Km relates to cavitation potential. Large values are desirable.
Butterfly valves have a greater potential for water hammer than globe valves. Butterfly valves are not as well understood in the HVAC industry as are. The industrial butterfly valves have been applied to various fields that transport fluid This valve flow coefficient is an important characteristic to investigate a valve performance and The valve loss coefficients in log scale value of two types of butterfly valve are presented in the vertical axis,Cited by: 7.
Maurice Stewart, in Surface Production Operations, Butterfly valves General considerations. The butterfly valve is a rotary valve in which a disk-shaped seating element is rotated 90° to open or close the flow passage. They are used in throttling service, particularly where large-size valves with automatic actuators are required.
The ball valves (both full ball and segmented ball) exhibit a nearly perfect (more so than most equal percentage globe valves) equal percentage inherent characteristic. High performance butterfly valves exhibit an inherent characteristic that is approximately midway between equal percentage and linear.
This book includes extensive and proven knowledge from leading experts in the process control field, including Face-to-Face Dimensions for Single Flange and Flangeless Butterfly Valves.
94 Face-to-Face Dimensions for High-Pressure, Offset Representative Sizing Coefficients for Rotary Valves. Related Topics. Control Valves - Control Valve terminology, bodies, trim, flow characteristics, Cv and Kv sizing, noise, actuators and positioners; Related Documents.
Ball Valve Flow Coefficients - C v - Flow coefficients - C v-for typical ball valves - reduced and full bore Leakage Classification of Control Valves - Seat leakage classification through control valves. The table below can be used to indicate butterfly valves and their flow coefficients at different open (or closed) positions.
Manufacturers data should always be checked before actual use. Flow Coefficient - C v; Valve Size Openness (disc angle) Maximum flow velocity (ft/sec) inches mm. Also, I have seen many cases of butterfly valves being vastly oversized – achieving maximum flow at 20% to 30% open.
This limits your effective control range to be from 5% to 25%. Add to this the valve’s nonlinear flow characteristic and you end up with a very poorly performing final control element. This book includes exten-sive and proven knowledge from leading experts in the process control field includ- Face-to-Face Dimensions for High Pressure Butterfly Valves Representative Sizing Coefficients for Rotary-Shaft Valves Valves are available with a wide variety of valve bodies in various styles, materials, connections and sizes.
Selection is primarily dependent on the service conditions, the task, and the load characteristics of the application. The most common types are ball valves, butterfly valves, globe valves, and gate valves. Ball Valves. Butterfly Valves - Torque, Head Loss, and Cavitation Analysis coefficients offset conditions analysis seating piping bearing flow rate chapter equation closed components velocity sizing Post a Review You can write a book review and share your experiences.
Other readers will always. flow characteristic will resemble its inherent flow characteristic. The desired result is to match a particular valve to a certain system. This could involve a very detailed analysis of the control loop. However, with a basic knowledge of valves and a few generalizations the process can be.
in the flow characteristics of ball valves and they proposed correlations to determine the loss and flow coefficients as functions of the valve opening for a ball valve of 38 mm in diameter. The research on butterfly valves concerned the investigation of valve performance for various valve and pipe configurations.
The effect of. Metso control valve sizing coefficients 5 HIGH PERFORMANCE TRIPLE ECCENTRIC DISC VALVES L-ANSI NELDISC®, HIGH PERFORMANCE TRIPLE ECCENTRIC DISC VALVE, METAL SEATED. valves and taps rotating or butterfly valves The head loss coefficient according on the valve opening angle depends on the hydraulic profile of the butterfly: for guidance, table 63 provides a few typical values; however, it is advisable to refer to manufacturer tables for greater clarification.
Advantages of Butterfly Valves. Butterfly valves are easy and fast to open. A 90° rotation of the handle provides a complete closure or opening of the valve. Large Butterfly valves are usually equipped with a so-called gearbox, where the handwheel by gears is connected to the stem.
This simplifies the operation of the valve, but at the expense. Flow Coefficient, Opening and Closure Curves of Butterfly Valves; Flow Coefficient, Opening and Closure Curves of Full Bore Ball Valves; Joukowsky Equation; Pumps.
Head to Pressure Converter; Reynold’s Number; Speed of Sound in Gas; Speed of Sound in Liquid; Mathematics. Expansion of Series; Geometry. 2D Shapes; Metric Decimal Prefixes; Solid.
For “linear characteristic”, the flow rate is directly proportional to the amount of travel of butterfly disk.
For example, at 25% open of butterfly disk, the flow rate of 25% of maximum flow. For “equal percentage characteristic”, equal increment of opening of butterfly disk leads to equal percentage change in flow rate. The butterfly valve is an improved type of valve which can be used for control of liquid, gas or particulate, viscous fluids with a simple, storable and compact structure.
These types of valves give opportunity for more economical control of fluids with zero sealing. Butterfly valves are classified as “quarter-turn” valves. The importance of butterfly valves has been more and more increasing in the pipe system.
And there are so many reports on the characteristics, i.e. the flow coefficient, the torque coefficient, the pressure recovery factor and so on.
Kerh et al.  performed an analysis of the butterfly valve on the basis of the experimental results.The most common characteristic curves are the quick opening, linear, and equal percentage curves. Valve manufactures can also design valves with modified linear, modified equal percentage, parabolic, and square root characteristics, as shown in the graph in Figure 1.Control Valves “Control valve” in this discussion means any pow-er-operated valve, whether used for throttling or for on-off control.
Other valve varieties such as motorized gate valves, louvers, pinch valves and self-operated regulators are not considered here. Figure Modern control valve combines actuator, valve assembly and digital.