Emerson Fisher V260 Brochure
Contents
1. prevent damaging cavitation while passing large particulate Process facilities don t have to be limited by the damaging effects of cavitation Emerson Process Management provides proven engineered solutions for these applications utilizing Fisher technologies Additional Industries Process industries such as mining pulp and paper life sciences and food and beverage experience cavitation challenges These industries use steam for motive force or process heating Steam generation requires high pressure water and involves processes that can cavitate Fluid control applications may combine cavitation with high viscosity multi phase fluid corrosion or coking or plugging fluid Emerson Process Management has Fisher control valves for all these challenges which are similar to those shown in this brochure but with variations in geometry and materials By utilizing local application engineers and experienced design engineers Emerson Process Management can deliver a custom solution for your special application View an animation video on cavitation at www FisherSevereService com Science of Cavitation Cavitation and Choked Flow Cavitation is a purely liquid flow phenomena gases cannot cavitate Choked flow may occur as a result of cavitation Choked flow occurs when the normal relationship between flow and increased pressure drop is broken With choked flow an increase in pressure drop by decreasing the downstream pressure d2. applications across multiple process industries Emerson Process Management uses multiple approaches to address application specific issues A large selection of Fisher cavitation control technologies is utilized for clean and dirty services Tiia G10 e Pressure distribution through Fisher Dirty Service Trim in a NPS 16 easy e valve body Application experience knowledge of cavitation science and the effect of valve size type trim style geometry and materials are all critical to providing reliable solutions Standard or custom Fisher control valves with anti cavitation trim can be used to control cavitation Fisher anti cavitation trim styles utilize multiple techniques such as pressure staging jet formation control and flowstream manipulation to control cavitation and prevent its damaging effects Materials of Design Since the standard materials used in valve bodies are relatively soft selection for cavitation resistance must rely on factors other than hardness In general as the chromium and molybdenum contents increase the resistance to damage from cavitation increases Thus the chromium molybdenum alloy steels have better resistance than the carbon steels and stainless steels have an even better resistance than the chromium molybdenum alloy steels Materials commonly used for cavitating services are R30006 CoCr A nickel chromium boron alloys solid and overlays hardened 44004 stainless steel harden
3. flow down direction only The trim design does not eliminate cavitation but controls where it occurs to minimize damage Micro Flat trim features a protected seat design to maximize seat life in cavitating environments The trim is available in hardened materials only such as R30006 CoCr A and 44004 These materials are needed to provide wear resistance between the plug and seat ring An outlet liner is provided to protect the valve body Micro Flat cavitation trim is recommended for angle valve applications In special cases it can be engineered into a globe valve body m 1 stage trim m Angle body m ASME Class 150 2500 m NPS 1 11 2 and 2 m Flow down design m 51 7 bar 750 psi pressure drop limit m ANSI FCI Class V shutoff PROVEN RESULTS SOLUTION Fisher Micro Flat trim RESULTS Reduced vibration improved control of low flows and extended trim life Fisher Cavitation Control Technologies 13 NotchFlo DST Control Valve utilizes a multi stage axial flow path where fluid flow is parallel to the axis of the plug and cage Pressure reduction occurs throughout the length of the plug Individual stages are not exposed to the full pressure differential NotchFlo DST trim uses a series of flow restrictions and expansions to control the pressure drop of the fluid The notched plug allows up to 12 mm 12 inch particulate to flow through the trim without plugging The amount of pressu
4. heat treatments tungsten carbide R30006 CoCr A and others are common m Sweep Flo angle body m ASME Class 150 2500 m NPS 2x3 3x4 4x6 and 6x8 m Flow down design m ANSI FCI Class V shutoff PROVEN RESULTS APPLICATION Ho t high pressure separator CHALLENGE A cavitating outgassing viscous fluid SOLUTION Fisher 461 valve with 316 SST R30006 CoCr A hardfaced trim RESULTS Withstood high pressure drop outgassing and cavitation issues plus provided accurate control 18 Fisher Cavitation Control Technologies Vee Ball Control Valve with Rotary Attenuator combines the efficiency of a rotary valve with the energy absorbing capability of special trim to provide improved performance for demanding applications The Fisher rotary attenuator design can be utilized in liquid service to reduce cavitation and vibration effects The Vee Ball with rotary attenuator has high application versatility and provides long service life Precise contouring of the V notch ball provides an approximately equal percentage inherent flow characteristic which is optimal for most flow control applications m 1 stage trim m ASME Class 150 300 600 m NPS 4 6 8 10 12 14 16 and 20 m 52 bar 750 psi pressure drop limit PROVEN RESULTS wee Seber egy a ntp Hee APPLICATION Greywater flow control CHALLENGE Standard ball valve was cavitating causing pipe vibration plus problems with the valve mounted i
5. technology is used without altering the integral GX bonnet design m stage trim m Globe body m ASME Class 150 300 m DN 25 40 and 50 NPS 1 1 and 2 m Flow down design m 27 6 bar 400 psi pressure drop limit m ANSI FCI Class V shutoff PROVEN RESULTS PRODUCTION Fertilizer APPLICATION Make up water CHALLENGE Control of low intensity cavitation SOLUTION Fisher GX valve with Cavitrol III trim RESULTS Long valve life in a compact package Fisher Cavitation Control Technologies 11 Cavitrol III Micro Flat Trim is a combination of distinct technologies The cage plug and seat ring are designed and manufactured as a unit The benefit is cavitation control for high pressure drops at very low flow rates The trim package also incorporates a protected seat for long shutoff life m2 3 or 4 stage trim m Globe or angle body m ASME Class 300 2500 m NPS 1 1 and 2 m Flow down design m 241 bar 3500 psi pressure drop limit m ANSI FCI Class V shutoff CH E ve V gh pressure drop cavitation and vibration SOLUTION Fisher Cavitrol Il Micro Flat trim RESULTS Provided accurate low flow control and prevented cavitation 12 Fisher Cavitation Control Technologies Micro Flat Trim utilizes a cavitation control mechanism consisting of special flow paths to prevent impingement on critical trim components Micro Flat trim is intended for low flow applications in the
6. the mean pressure sufficient to initiate cavitation in very localized regions Typically cavitation begins before the minimum mean pressure is reduced to the vapor pressure Standard liquid sizing fully accounts for the capacity concern associated with choked flow and prevents undersizing the valve Additional empirical information is required to predict different levels of cavitation 4 Fisher Cavitation Control Technologies Effects of Damage Factors Affecting Cavitation Damage Cavitation doesn t always cause damage when it occurs The extent of cavitation damage is a function of the following factors Intensity magnitude of pressure drop Greater drops in pressure increase the potential for damage Materials of construction Hardened materials reduce damage Examples include R30006 CoCr A nickel chromium boron alloys hardened 44004 stainless steel hardened 17400 stainless steel and hardened 41000 S41600 stainless steel Time of exposure The longer cavitation occurs in an area the more likely it is to result in damage m Quantity of flow Cavitation issues generally scale with flow rates A larger flow rate means more fluid is available to cavitate and there is a greater potential for cavitation damage m Valve trim design Fisher control valve trim can be selected to combat the damaging effects of cavitation using isolation or elimination techniques m Leakage while closed If seat le
7. your local Emerson Process Management sales office There are several factors that determine a material s performance in a cavitating situation including its toughness hardness and corrosion resistance in the application environment These factors are discussed in the materials of design section This valve plug has sustained extensive cavitation damage It shows a complete loss of seating surfaces Excessive Noise and Vibration Cavitation can cause unacceptable noise and vibration Although the noise associated with a cavitating liquid can be quite high it is usually a secondary concern when compared to the material damage that can exist Cavitation is frequently described as sounding like gravel in a pipe but the character of cavitation noise can vary widely Damaging cavitation can take place without noise and the level of noise and vibration from a control valve may not always coincide with the cavitation damage level Vibration resulting from cavitation may be more prevalent than cavitation damage It can affect the valve positioner linkage tubing and adjacent pipe Normal turbulent flow in a transparent pipe Cavitation and turbulent flow vary with pressure drops Note the variation in flow fields between this image and the second image despite identical service conditions Fisher Cavitation Control Technologies 5 Emerson Innovation Fisher Technology Development The Emerson Innova
8. HALLENGE 31 bar 450 psi 120 decibels and vibration SOLUTION NPS 12 Fisher V260 valve with Hydrodome attenuator RESULTS Uninterrupted service for 8 years and reduced noise to 90 decibels Emerson Process Management Marshalltown lowa 50158 USA Sorocaba 18087 Brazil Chatham Kent ME4 4QZ UK Dubai United Arab Emirates Singapore 128461 Singapore www EmersonProcess com Fisher Severe Service D351912X012 MX14 H Apr11 Fisher Controls International LLC 2011 All Rights Reserved Fisher FIELDVUE PlantWeb Cavitrol NotchFlo and Vee Ball are marks owned by one of the companies in the Emerson Process Management business division of Emerson Electric Co Emerson Process Management Emerson and the Emerson logo are trademarks and service marks of Emerson Electric Co All other marks are the property of their respective owners The contents of this publication are presented for informational purposes only and while every effort has been made to ensure their accuracy they are not to be construed as warranties or guarantees express or implied regarding the products or services described herein or their use or applicability All sales are governed by our terms and conditions which are available upon request We reserve the right to modify or improve the designs or specifications of such products at any time without notice Neither Emerson Emerson Process Management nor any of their affiliated entities assumes responsibil
9. Solutions to Cavitation Problems al wwzaarliin TN mat TE ney ae EMERSON Process Management Severe Service 2 Fisher Cavitation Control Technologies Control Valve Cavitation Cavitation is a concern for plant operators and maintenance personnel because it can reduce plant availability and profitability Cavitation not only decreases flow capability through control valves but it may also cause material damage excessive noise and excessive vibration A wide range of Fisher cavitation control technologies are available for clean and dirty service Included in this brochure are images of Fisher technologies with descriptions specifications and proven results Hydrocarbon and Petrochemical Industries Hydrocarbon and petrochemical industries are built on reliable liquid process control Typical fluids include crude oil with multiple chemical compounds and particulate highly refined single compounds such as butane and complex intermediates These fluids are transported and processed in a variety of ways Applications are driven by pump reaction or vertical head In all cases the process equipment must be correctly sized and selected to attain the best loop control minimize process variability and deliver the best process results Cavitation is an unintended occurrence in many of these processes Mixture hydrocarbons such as crude oils may have less damage potential than a similar ap
10. akage occurs when a valve is closed the liquid moves quickly from a high pressure area to a low pressure area which may result in cavitation and potential damage m Fluid Fluid behavior should be considered in trim selection For instance water in a power plant behaves differently than crude oil for the same service conditions Material Damage Physical damage to a control valve due to uncontrolled cavitation is a concern because of the high maintenance cost inconvenience unpredictability and unplanned downtime Damage can consist of a mechanical and selective chemical attack on the material surface Typically cavitation damage is characterized by a very irregular pitted rough appearance Valve parts with extensive damage may have large amounts of material missing The mechanical attack can occur in two forms microjet impingement and shockwave impingement Microjet impingement causes erosion of the material surface Shockwave impingement causes material deformation and failure A chemical attack occurs when the protective passive oxide layer is physically removed from the base metal during the mechanical attack The base material is left vulnerable to further chemical attack The science of vapor cavity nucleation growth collapse and rebound is at the core of cavitation damage Rather than go through the science the focus will be on how to reduce cavitation effects Further information is available by contacting
11. aped holes the hole shape reduces fluid turbulence In addition the holes are radially aligned to flow from one restriction to another This action is pressure staging dividing the total drop into smaller increments Both features dissipate the fluid pressure and prevent cavitation m1 2 3 or 4 stage trim m Globe or angle body m ASME Class 300 2500 m NPS 1 24 m Flow down design m 276 bar 4000 psi pressure drop limit m ANSI FCI Class V shutoff The optional Protected Inside Seat technology shown right has seating surfaces on the inside tip of the valve plug and the radius in the groove of the seat ring so shutoff surfaces are not exposed to potential erosion m2 3 or 4 stage trim m Globe or angle body m ASME Class 900 2500 mNPS 2 6 m Flow down design m 276 bar 4000 psi pressure drop limit a Shutoff Position PROVEN RESULTS APPLICATION Boiler feedwater drum level system CHALLENGE Seat leakage due to cavitation and frequent trim replacement SOLUTION NPS 6 Fisher HPT valve with 4 stage Cavitrol Ill trim and Class V shutoff RESULTS Operating time increased by 50 and control was improved 10 Fisher Cavitation Control Technologies GX Valve with Cavitrol III Trim lowers hydrodynamic noise and vibration by utilizing a proprietary drilled hole shape and spacing The special hole technology and flow down design reduces and isolates cavitation to prevent damage Cavitrol Ill
12. area The result is very efficient operation because more than 90 percent of the overall pressure drop is taken in the initial stages where there is little danger of cavity formation Consequently a relatively low inlet pressure to the final stage is achieved Due to the need for tight shutoff this multi stage trim incorporates a protected seat design that separates the shutoff and throttling locations All significant pressure drops are taken downstream of the valve seat As a result the seating surfaces are not worn away by throttling control action so shutoff capabilities are extended E 3 4 or 5 stage trim m Angle body m ASME Class 2500 4500 mNPS 2 10 m Flow down design m 552 bar 8000 psi pressure drop limit m ANSI FCI Class V and VI shutoff PROVEN RESULTS D CHALLENGE 538 bar 7800 psi pressure drop water at 204 C 400 F SOLUTION NPS 10 Fisher block forged valve with 5 stage Cavitrol IV trim RESULTS Withstood high pressure prevented cavitation and provided accurate control 16 Fisher Cavitation Control Technologies Dirty Service Trim for Outgassing DST G is a multi stage control valve trim design It is used in services where the fluid has dissolved gases that are released from solution due to a reduction in pressure The fluid may also contain entrained particulate DST G is mainly used in refining petrochemical and oil and gas applications Outgassing can cause two
13. ed 17400 stainless steel and hardened 41000 S41600 stainless steel Detailed view of the flow pathlines through the trim Cavitation Coefficient The Fisher cavitation coefficient indicates the potential for damaging cavitation in a control valve It is dependent on several factors m Valve trim style m Service conditions m Fluid properties m Intensity magnitude of pressure drop m Materials of construction m Length of exposure m Quantity of flow The Fisher cavitation coefficient predicts the onset of cavitation related damage It is available for every Fisher cavitation control product throughout its full intended application range Other vendors utilize similar application guidelines The user is cautioned to always use the guideline associated with the chosen vendor The coefficient is not interchangeable Predicting the onset of damaging cavitation is an arduous task Emerson Process Management s field experience research capabilities and subject matter expertise in fluid behavior help improve the ability to predict damaging cavitation Fisher Cavitation Control Technologies 7 Plant Designs that Prevent Cavitation Process Loop Design Flow conditions that will produce damaging cavitation can often be avoided at the design phase of a project by giving proper consideration to service conditions and the process loop design Process loop design can influence cavitation in a control valve F
14. es FIELDVUE digital valve controllers installed on Fisher cavitation control valves protect your process by giving a view of operating characteristics such as supply pressure control signal friction and seat load FIELDVUE Performance Diagnostics run continuously analyzing valve and actuator data while the valve remains in service If problems are detected information can be directed to the appropriate personnel automatically when installed in a PlantWeb system These notifications help you keep the control valve and the process loop functioning optimally j aA eit 2 2S 3 oe ba Bai a Me hai ae 5 a Pe wae a M g Sore prot i T tate 4 Sega Tki P i f ry as Lit Jou rj Wera i rh Reliable Cavitation Control Emerson Process Management was a pioneer in understanding cavitation related problems in control valves Through this understanding Emerson Process Management has lead the way in engineering and manufacturing cavitation control trims that solve customers issues Correct engineering and manufacturing of anti cavitation trims is critical to their overall operation and life expectancy Holding tight tolerances selecting correct materials and correctly staging the pressure drop can be the difference between extended trim life or an unplanned shutdown Confidence in cavitation solutions relies on true OEM engineering and manufacturing specifications Non OEM solutions may appear to offer c
15. igure 1 shows a valve installation and pressure plot where the majority of the pipe system is upstream of the valve Looking at the pressure along the pipe or loop the valve is positioned where P is close to P and the likelihood of cavitation in the control valve is high In Figure 2 the valve has been relocated so the majority of the system is downstream Now P associated with the valve is higher and thus much different from P_ therefore the likelihood of cavitation is much lower This demonstrates the value of locating the valve to leverage the natural pressure distribution in a system These simple diagrams show only pipe but the effect of all system elements such as reactors vessels and pumps must be considered in a loop pressure review If valve placement is not flexible flow resistance can be added downstream of the control valve utilizing an orifice plate or a second valve Fluid pressures within the valve increase and it will experience less pressure drop However this technique may simply displace cavitation from the valve to the downstream restriction and may not effectively control the cavitation in the system This may also increase valve size as less pressure drop is available to process the same amount of flow PRESSURE PRESSURE 8 Fisher Cavitation Control Technologies Are You Willing to Take the Risk FIELDVUE Performance Diagnostics Reliability is a key requirement for all process faciliti
16. ity for the selection use or maintenance of any product Responsibility for proper selection use and maintenance of any product remains solely with the purchaser and end user EMERSON Process Management
17. nstrumentation SOLUTION NPS 10 Vee Ball control valve with rotary attenuator RESULTS The rotary attenuator eliminated vibration and noise caused by vibration and instrument issues were resolved Fisher Cavitation Control Technologies 19 V260B Ball Valve with Hydrodome Attenuator provides improved performance for demanding applications such as pump bypass and pipeline take off The attenuator trim is designed for liquid service to help eliminate or reduce cavitation and associated pipeline noise and vibration The V260B is a full bore ball valve designed with features for optimized pressure flow and process control An integral drilled attenuator controls noise and vibration from high pressure drop liquids The splined shaft connection to the actuator reduces lost motion The V260B with Hydrodome attenuator combines the efficiency of a rotary valve with the energy dissipating capability of a special trim to provide improved performance for demanding applications The valve is available with single and dual Hydrodome configurations The Hydrodome attenuator is active throughout the ball rotation for very demanding services or a characterized attenuator as shown is used to match the service conditions m 1 or 2 stage trim m ASME Class 150 300 600 900 i m NPS 8 10 12 16 20 and 24 m 103 bar 1500 psi pressure drop limit PRODUCTION Crude oil APPLICATION Delivery valve for pipeline take off location C
18. oes not result in more flow through the restriction Q GPM mm CHOKED FLOW RATE AP CHOKED Basic valve sizing equations imply that for a given valve flow should continually increase by simply increasing the pressure differential across the valve In reality the relationship given by these equations holds true for only a limited range As the pressure differential is increased a point is reached where the flow increase stops This condition of limited maximum flow is known as choked flow Consider the simple restriction shown to the right The pressure of the liquid P is plotted as a function of the distance X through the restriction As a liquid passes through a reduced cross sectional area velocity increases to a maximum and pressure decreases to a minimum As the flow exits velocity is restored to its original value while the pressure is only partially restored thus creating a pressure differential across the device There is a point along the flow path called the vena contracta where the flow area and pressure are at a minimum and the velocity is at a maximum When this point is reached the local pressure may drop to or below the vapor pressure of the liquid forming vapor cavities The density of the liquid vapor mixture continues to decrease until the compressible choked flow limit is reached The distance from the restriction to the vena contracta will vary with the pressure conditions and type
19. of restriction After the vena contracta the liquid pressure will recover to or below the downstream pressure If the downstream pressure is higher than the vapor pressure the vapor cavities will collapse This is cavitation If the downstream pressure stays at or below the vapor pressure the vapor cavities do not collapse and the vapor expansion continues This is known as flashing Fisher Cavitation Control Technologies 3 As the pressure recovers the vapor cavities implode forming high speed destructive microjets and localized shock waves Either of these mechanisms when located near the material surface can cause severe damage to valve elements such as the plug seat body and associated pipe PRESSURE DISTRIBUTION REALISTIC E CFE e P VAPOR PRESSURE ATT Pie VENA CONTRACTA The model above depicts mean fluid pressure Flow through control valves causes significant deviations from the mean pressure Deviations include instantaneous pressure fluctuations associated with fluid turbulence and low pressures in the cores of vortices and eddies associated with boundary layer separation free shear zones stagnation regions and re entrant zones These explain some of the differences seen between the textbook view represented by the blue line and realistic computational fluid dynamics represented by the yellow line These phenomena can produce local pressures significantly higher or lower than
20. ost effective solutions in the short term but introduce new risks of unexpected shutdowns and lost production Are you willing to take this risk Emerson Process Management provides the quality accuracy and engineered solutions demanded by these difficult cavitation services Local service is provided before and after the sale Emerson Process Management sales offices are backed by global manufacturing sites that can effectively manufacture measure and assemble these highly engineered solutions No matter where your Fisher cavitation control technology is manufactured product quality remains the constant that our engineers demand and our customers deserve Parts and services are available to minimize downtime and maximize throughput If you have an existing installation with a cavitation problem or you want to ensure that your next installation will not experience its damaging effects contact your Emerson Process Management sales office You will receive the support needed to accurately size select and install the solution to your cavitation problem Comprehensive information on cavitation is available from your local sales office or from www FisherSevereService com Fisher Cavitation Control Technologies 9 Cavitrol Ill trim is used for cavitating liquid applications in various globe and angle valve bodies Cavitrol III trim can effectively eliminate cavitation damage The cage contains a multitude of specially sh
21. plication on water but highly refined fluids such as gasoline blends can cavitate with the same damage potential as water Crude oils often carry particulate that will plug the small flow passages in some cavitation control designs Supporting hydrocarbon and petrochemical industries with cavitation solutions requires a broad range of valve designs covering clean to dirty fluids benign to very corrosive fluids and flow rates requiring NPS 1 to 48 and larger Power Industry All power or process steam plants whether traditional coal fired integrated gasification combined cycle nuclear or combined cycle have the potential to experience cavitation and its related effects This is due to the high pressure water and pressure drops experienced in applications such as boiler feedwater startup pump recirculation and desuperheater spraywater The negative effects of cavitation in these applications can be effectively combated by utilizing one of the many Fisher technologies Special consideration should be given to the chemistry of the water as well as the presence of particulate which is common in these applications For example the use of R30006 CoCr A in boiler feedwater may be acceptable depending on the amount and type of amines present The use of anti cavitation trims should be evaluated based on the presence of particulate weld slag and magnetite A variety of trim styles such as Fisher dirty service trims are available to
22. re drop per stage is designed to prevent cavitation problems and minimize erosion issues on a properly sized valve Due to the need for tight shutoff this multi stage trim incorporates a protected seat design that separates the shutoff and throttling locations All significant pressure drops are taken downstream of the valve seat As a result the seating surfaces are not worn away by throttling control action so shutoff capabilities are extended E 3 4 or 6 stage trim m ASME Class 150 1500 globe body m ASME Class 150 2500 angle body mNPS1 8 m Flow up design only m 290 bar 4200 psi pressure drop limit m ANSI FCI Class V shutoff m Ability to pass 12 mm 42 inch particulate depending on valve size PROVEN RESULTS AK N R g liquid with entrained solids at 103 bar 1500 psi CHALLENGE Seat erosion noise levels up to 120 decibels and pipe vibration SOLUTION Fisher NotchFlo DST control valve RESULTS Quiet operation long seat life and reduced lost product and flare emissions 14 Fisher Cavitation Control Technologies Dirty Service Trim DST provides cavitation control for applications with entrained particulate that could potentially plug the flow passages or cause severe erosion damage to conventional anti cavitation trim The DST design uses a combined axial and radial flow path that features large openings allowing particulate up to 19 mm 34 inch in diameter to pass through the valve D
23. tion Center for Fisher Technology in Marshalltown lowa USA is home to the world s largest flow lab used to evaluate control valves It incorporates flow testing capabilities up to NPS 36 and 240 bar 3 500 psig Final control elements are tested in conformance to IEC and ISA standards in real world plant conditions to ensure production reliability efficiency environmental compliance and safety Emerson engineers conduct tests that analyze cavitation materials fatigue wear high and low temperatures valve actuators valve instrumentation seismic requirements reliability loop variability leakage hydrostatic forces gaskets seals and control system compatibility In the controlled lab environment special tests are commonly performed to answer customers questions Emerson engineers conduct noise and vibration tests on cavitating applications in many different ways Transparent pipe allows visualization of the cavitation field Cavitation demonstrations can be arranged with your local Emerson Process Management sales office 6 Fisher Cavitation Control Technologies Matching Applications to Design Valve Selection and Design When service conditions and the process loop design are fixed a control valve may have to operate at pressure conditions that normally result in cavitation In such instances source treatment will be needed Clearly a single product design is not sufficient for the wide variation of
24. types of damage One type is cavitation as discussed previously The other is erosion from a rapidly expanding flowstream The DST G trim employs the basic design from the standard DST trim but utilizes a different design for the lower cage The DST G lower cage controls jet formation and discharge into the body to prevent vibration and erosion The trim accomplishes all this while allowing large 6 35 mm inch particulate to pass through m Multi stage trim m Angle body m ASME Class 150 2500 mNPS 1 12 m Flow down design m 175 bar 2500 psi pressure drop limit m ANSI FCI Class V shutoff PROVEN RESULTS VA pressure flash drum 2 C Hot low CHALLENGE Outgassing large particulate and cavitation SOLUTION Fisher DST G RESULTS Reduced vibration enabled long seat life and provided reliable long lasting throughput Fisher Cavitation Control Technologies 17 461 Sweep Flo Angle Valve is self cleaning with an expanded outlet It is typically used in the chemical and hydrocarbon industries where cavitation control is required for residual oils that experience coking have high particulate content and viscosity and may outgas This cavitation control valve construction consists of carefully designed flow paths that control impingement and material selections aimed at maximizing corrosion and erosion resistance For instance trims such as 17400 stainless steel in a variety of
25. ue to the need for tight shutoff this multi stage trim incorporates a protected seat design that separates the shutoff and throttling locations All significant pressure drops are taken downstream of the valve seat As a result the seating surfaces are not worn away by throttling control action so shutoff capabilities are extended DST is an expanding flow area design Each stage has a successively larger flow area The result is very efficient operation because typically 80 of the pressure drop is taken prior to the final stage where there is little danger of cavity formation Consequently a relatively low inlet pressure to the final stage is achieved E 2 3 4 5 or 6 stage trim m Globe or angle body m ASME Class 150 2500 m NPS 1 24 m Flow down or flow up design m 290 bar 4200 psi pressure drop limit m ANSI FCI Class V shutoff m Can be used in easy e EH EHA EW HP and HPA valves m Ability to pass 19 mm 34 inch particulate depending on valve size PROVEN RESULTS P ter injection CHALLENGE High pressure drop particulate and tight shutoff needed SOLUTION Fisher Dirty Service Trim DST RESULTS Cavitation control with no cage plugging long term shutoff and extended time between shutdowns Fisher Cavitation Control Technologies 15 CAV4 Control Valve with Cavitrol IV trim has an expanding flow area design Each of the Cavitrol IV trim stages has a successively larger flow
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