Transcription

Valtek Mark Onefor Power Services

Valtek Mark One-PowerIntroductionFail-safe SpringReversible PistonActuatorOSHeavy-DutyStem GuidingFour-way Positionerfor PositioningAccuracyLarge Diameter,One-PiecePlug StemClamped-in Seat RingInterchangeabilityClass 600 bodyE0037Figure 1: Valtek Mark One-PowerTM Control ValveTMThe Valtek Mark One-Power globe control valveoffers superior performance in liquid and gaseous services, while permitting easy, fast and inexpensive maintenance in power services.The Valtek Mark One-P is the ideal choice for hightemperature and pressure applications, which demandprecise throttling. Factory Mutual approval for use as afuel service valve and ASME “N” stamp also adds to itsversatility in power services.Unlike diaphragm-operated control valves, the springcylinder-actuated Valtek Mark One-P provides stiffnessand maintains high-positioning accuracy, repeatability,controlled high speed and faithful response. Intensefluid pressures are easily controlled by the compact, yetpowerful design. Each actuator is capable of utilizingsupply pressures up to 150 psi (10.3 Bar).2Most diaphragm actuators rely entirely on springs toclose the valve. The Valtek Mark One-P's spring, supplyair pressure and fluid pressure combine to produceexceptionally tight shutoff. A heavy-duty, one-pieceplug and self-aligning seat ring further enhance theshutoff capability of the Valtek Mark One-P.The clamped-in seat, top-entry trim also permit easy,quick maintenance. A high degree of parts interchangeability results in fewer inventory parts. The actuator islighter, smaller and easier to handle than comparablediaphragm actuators.The Valtek Mark One-Power control valve is the idealcontrol valve solution for power services.Flowserve Corporation, Valtek Control Products, Tel. USA 801 489 8611

Valtek Mark One-PowerValtek SolutionThe Valtek Mark One-Power control valve offers solutions to many power services challenges. Five basicconfigurations (globe, angle, three-way, expanded outlet and Y-body) can be used in various steam, water, fueland chemical applications. Several anti-cavitation and noise reduction trims, full ASME “N” capability and FM fuelvalve approval also expand the service usability of the Valtek Mark One-P.Common Control Valve ProblemMark One-Power SolutionYoke breaksDuctile iron yokes are highly resistant to breakagePlug head comes off;stems breakOne-piece plug head and stem; stems are heavy-duty – at least twotimes the diameter of most manufacturers' stemsValve leaksDouble-acting, high-thrust cylinder actuator allows most applications toavoid pressure-balanced trims and to use the fluid to assist valve closure;self-centering seat assures tight shutoff with no lapping required;Alloy 6 hard facing or 416 stainless steel heat treated trim reduces wiredraw and seat surface damageActuators destroyed byActuators are available with Viton O-rings for operation to 350 F / 177 C;high temperatures high-temperature positioners are also availablePacking leaksHeavy-duty, double top stem guiding eliminates lateral stem movement –increasing packing lifeDifficult to attach plug andThreaded actuator stem and one-piece stem clamp makes assemblyactuator stem quick and easyHard to remove seat or retainerClamped-in seat allows for easy removal – no corroded threads to hinderservice workDifficult to remove yoke/Two stainless steel half-clamps make actuator removal easy – even afterbonnet nut years of serviceSpace constraints in existingCompact actuator design assures the valve will fit in the existing spacepipingLarge spare parts stock requiredGreater interchangeability such as three standard actuators and a minimum Class 600 body reduces the amount of spare parts requiredSevere service applicationsThe Valtek Mark One-P valve can easily be engineered with severewithin the plant service trims: CavControlTM, ChannelStream ,MegaStreamTM and Tiger-ToothTM; body and trims are available in mostmaterials to meet application requirementsDifficult to serviceThe Valtek Mark One-P valve has top-entry trim, a clamped-in seat ring,and one-third the parts of other manufacturers’ valves; actuator islightweight and easier to handle than diaphragm actuators.Unstable flow controlSpring cylinder actuator with 4-way positioner accepts 150 psi / 10.3 Barair supply ensuring high thrust, low hysteresis and low repeatabilityFlowserve Corporation, Valtek Control Products, Tel. USA 801 489 86113

Valtek Mark One-PowerComponentsAdjusting Screw GasketAdjusting ScrewSpring ButtonSpringPiston Retaining NutPiston Stem O-ringActuator Stem SpacerCylinderActuator Stem BushingPistonActuator Stem O-ringPiston O-ringActuator StemYoke O-ringStem ClampOStroke PlateGland FlangeUpper PackingYoke ClampPacking SpacerCylinder Retaining RingSStem BellowsYokeUpper Stem GuideBonnetBonnet FlangeBoltingBonnet FlangeSeat RetainerLower PackingSeat RingBonnet GasketSeat RingGasketLower StemGuideBodyPlugE0038Figure 2: Valtek Mark One-Power Control Valve4Flowserve Corporation, Valtek Control Products, Tel. USA 801 489 8611

Valtek Mark One-PowerBody StylesE0040E0039Figure 3: Globe-style BodyFigure 4: Three-way BodyGlobe-style bodies feature smooth, streamlined, constant area internal passages with no pockets, permittinghigh capacity with minimum turbulence. They aredesigned with nearly constant wall thickness, providinglower weight and cost when the body is manufactured inexpensive stainless or alloy steels.Three-way bodies are used for either combining ordiverting services. Due to excellent parts interchangeability, a standard globe valve easily converts tothree-way service with the addition of a three-wayadaptor, upper seat ring, two gaskets and a three-wayplug.E0042E0041Figure 5: Angle-style BodyFigure 6: Expanded Outlet BodyThe Valtek Mark One-Power can be easily adapted toan angle style body – all other valve parts remain thesame. For additional protection of the body, a specialventuri seat ring, which extends to the outlet flange, isavailable if required.When a small control valve is needed in a large pipe,the expanded outlet body can be used – all other partsare interchangeable with the globe body. Manypower plants use this valve design in heater drainapplications.Flowserve Corporation, Valtek Control Products, Tel. USA 801 489 86115

Valtek Mark One-PowerEnd ConnectionsValtek Mark One-Power end connections are availablein five configurations including buttweld, socketweld,threaded, raised face integral and raised face separable. The five end connections make the Valtek MarkOne-P valve applicable to all power industry applications. In addition, Flowserve can custom engineer endconnections to meet individual needs.E0044E0043Figure 7:Buttweld End ConnectionIntegral FlangeFigure 8:Socketweld End ConnectionThreaded (NPT)Separable FlangeE0045Figure 9: Additional End Connections6Flowserve Corporation, Valtek Control Products, Tel. USA 801 489 8611

Valtek Mark One-PowerGaskets, Yoke ClampsThe Valtek Mark One-P is designed with the bonnet andseat ring gaskets fully retained. The bonnet clampsmetal-to-metal in the body creating a primary seal,which is backed up by the gasket. The bonnet gasketcompression is determined by the depth of the gasketstep on the bonnet, which is machined to provide thenecessary gasket compression. Having the bonnetsecured metal-to-metal in the body also ensures propervertical plug alignment in the seat to help maintain tightshutoff.When the bonnet is fully installed, force is transmittedthrough the seat retainer to secure the seat ring inposition. Compression of spiral-wound gaskets prevents leakage and the self-centering seat ring mateswith the plug head, without the need for lapping.Bonnet GasketSeat RingGasketE0046Figure 10: Body GasketsTable I: Gasket SpecificationsGeneralTemperatureRatingTypeGasket MaterialMaximumGasketTemp. F / CMinimumGasketTemp. F / CFlatPTFE350 / 177-200 / -130MediumSpiral Wound316 S.S. w/ graphite*750 / 400-20 / - 30High**Spiral WoundINCONEL w/ graphite1000 / 538-20 / - 30Low* Valtek Mark One-P standard gasket material** Higher temperatures are available with special gasket designsYoke ClampsThe actuator is commonly attached to the Valtek MarkOne-P body assembly with two precision-cast, stainless- steel yoke clamps, although on large valves theactuator is bolted directly to the bonnet. Each clamp hasan inclined plane surface which, when bolted together,securely fastens the actuator yoke to the bonnet. Unlikeconventional threaded clamps, the Valtek Mark OnePowers’ clamp design permits easy removal even underextremely dirty or corrosive conditions.Associated bolts and locknuts are supplied in platedcarbon steel, although stainless steel is also availablewhen required.Flowserve Corporation, Valtek Control Products, Tel. USA 801 489 8611YokeClampE0047Figure 11: Yoke Clamp7

Valtek Mark One-PowerBonnet Types, Packing BoxE0048Standard BonnetExtended BonnetFigure 12: Valtek Mark One-P Bonnet TypesStandard BonnetExtended BonnetThe Standard Valtek Mark One-P bonnet is constructedof the same material as the body and handles temperatures up to 750 F / 400 C in Class 150 – 600 bodydesigns and to 800 F / 427 C in Class 900 – 2500body designs. (See Table 3 on page 9 for packinglimitations.)The extended bonnet protects the packing from excessive heat, which may inhibit valve performance. Carbonsteel constructions can withstand temperatures up to800 F / 427 C and 316 stainless steel configurationscan withstand temperatures from -150 F to 1500 F /-100 C to 816 C.Packing BoxStandard Valtek valve packing boxes are deeper thanmost conventional types, providing these advantages:1. The spacing between the wiper set and the main,upper packing set prevents contamination of theupper packing. The upper set is positioned far enoughaway from the wiper set to avoid contact with any partof the plug stem that has been exposed to the flowingmedium. The wiper set is designed to minimize theamount of fluid on the plug stem.2. Bonnets are designed to permit a wide variety ofpacking configurations, including a double set ofpacking, without changing bonnets.83. Two widely spaced stem guides, when used withValtek Mark One-Power’s large-plug stem diameter,provide exceptional guiding. The upper stem guidealso acts as a packing follower; the lower guide issituated close to the plug head for additional guiding support, ensuring accurate alignment of the plugand seat ring.4. Solid lower guides (bronze or Alloy 6) are used inall high differential-pressure services to ensurerigid guiding and no stem movement. Limitinglateral stem movement (wobble) extends packinglife.Flowserve Corporation, Valtek Control Products, Tel. USA 801 489 8611

Valtek Mark One-PowerPacking and GuidingTable II: Packing Temperature Limitations for Standard and Extended BonnetsValve ANSIRatingPackingMaterial/TypeStandard Bonnet (1) F C(4)-30 to 400-20 to 750Extended Bonnet (1) F C-20 to 1200-30 to 650-20 to 750(4)-30 to 400-20 to 1500-30 to 816PTFE-20 to 450-30 to 232Braided PTFE(3)Glass-filled PTFE-20 to 500-30 to 427-150(2) to 600-100 to 316Asbestos-free packing-20 to 800-30 to 427-20 to 1200-30 to 650Graphite(6)-20 to 800-30 to 427-20 to 1500-30 to 816PTFE-20 to 450-30 to 232Braided PTFEGlass-filled PTFE-20 to 500-30 to 260-150(2) to 700-100 to 371SafeGuard(7), SureGuard(7)-20 to 450-30 to 232-20 to 600-30 to 316-20 to 550-30 to 288-20 to 700-30 to 371-20 to 450-30 to 232-20 to 700-30 to 371-20 to 550-30 to 288-20 to 800-30 to 427Asbestos-free packingAFPI(5)150 - 600Graphite(6)AFPI(5)900 - 2500150 - 600SureGuard XT900 - 2500(7)(7)(7)SafeGuard , SureGuardSureGuard XT(7)(1) B16.34, 1988, specifies acceptable pressure/temperature limits for pressure retaining materials.Consult factory for additional information.(2) If the appropriate body and bonnet materials are used.(3) PTFE is rated to -423 F / -253 C.(4) 8 to 12-inch, Class 150 – 600; and 3 to 12-inch, Class 900 – 2500 can be used to 850 F / 454 C.(5) Asbestos-free, high temperature packing. (all major brands available)(6) Do not use Graphite above 800 F / 427 C in oxidizing service such as air.(7) Low leakage, low maintenance packing.Table III: emperatureMaximumPressureGraphite lined SS**1500 F / 816 C-320 F / -196 C1400 psig / 96.6 Barg thru 2-inch1000 psig / 69.0 Barg 3 thru 4-inch850 psig / 58.6 Barg 6-inch & upGlass-filledPTFE-lined S.S.350 F / 177 C-423 F / -253 C150 psig / 10.3 Barg @100 F / 38 C100 psig / 6.9 Barg @ 350 F / 177 CSolid Bronze500 F / 260 C-423 F / -253 CSame as bodySolid Alloy 61500 F / 816 C-423 F / -253 CSame as body* Refer to Sizing & Selection 12 for specific application guidelines.** Do not use Graphite above 800 F / 427 C in oxidizing service such as air or oxygen. The use of Graphite packing may requireoversize actuators or heavier springs due to added friction.Flowserve Corporation, Valtek Control Products, Tel. USA 801 489 86119

Valtek Mark One-PowerTrim Types, Flow Characteristics, Hard FacingTrim TypesValtek Mark One-P trims can easily be converted fromone trim type to another. All seat rings and plugs withina given size and pressure class are interchangeable.Multiple trim reductions are available by changing onlythe plug and seat. Many other parts are interchange-Equal Percentageis the characteristicmost commonlyused in processcontrol.able between pressure classes (150 thru 600 and 900thru 1500).Standard full-area trim provides maximum CV. Reducedtrim is available in a wide variety of sizes when lower CVand large bodies are required.Quick Openfor on-offservice.Linear plugs are usedon systems wherevalve pressure drop isthe majority of thesystem pressure drop.Most power plants use linear trim to minimize occurrence of water hammer.E0049Figure 13: Flow CharacteristicsTable IV: Material Hardness RatingsTrimMaterialHardnessRockwell CCorrosion*Resistance316 S.S.8Excellent416 S.S.40FairAlloy 644Good to Excellent440C S.S.56Fair* General rule only. Check specific application.Full AreaReducedE0050Figure 14: Typical Trim TypesHardened TrimFor smaller valves the standard plug and seat ringmaterial is 416 stainless steel, with solid Alloy 6plug head and a 316 stainless steel stem as optional trim. On larger valves 316 stainless steel isused, with Alloy 6 or other overlays as an option. Ageneral rule is to consider hardened trim for allsteam and high differential pressure applications.These materials offer a good combination of relative hardness and corrosion resistance. Specialalloy trims and hard facings are also available.10Seat SurfaceFull ContourLower GuideAreaFull ContourLower GuideE0051Figure 15: Hard Facing Variations – SeatFlowserve Corporation, Valtek Control Products, Tel. USA 801 489 8611

Valtek Mark One-PowerPressure-balanced Trim, Seats, SealsBonnetSleeve GasketPlug SealsPlug VentPlugPressure-balancedSleeveE0052Figure 16: Pressure-Balanced TrimPressure-balanced TrimMetal SeatsFor extremely high-pressure drops, pressure-balancedtrim is used to reduce the thrust necessary to stroke theplug by reducing the trim off-balance area.Unbalanced metal-seated valves attain a standard ofClass IV shutoff (ANSI\FCI 70-2, 1991), although Class Vis optional. Class IV calls for maximum permissible seatleakage of 0.01 percent of rated valve capacity. All Valtekvalves are seat-leak tested after assembly and generally are substantially lower in leakage than called for bythis class. This exceptional seat tightness is obtained byaligning the seat ring with the plug during assembly.The seal area less the stem area is designed to beslightly larger than the seat area. This results in an offbalanced plug which aids the valve to close for flowunder the seat and to open for flow over the seat. Flowdirection is generally under the plug for fail-closed andover the plug for fail-open.Table V: Pressure-balanced SealTemperature RangesSeal MaterialTemperature RangeMulti-seal piston rings*(1)300 to 1600 F / 150 to 870 CNi-Resist piston rings(1)300 to 600 F / 150 to 316 CKalrez O-ring-20 to 550 F / -30 to 288 CAflas O-rings-40 to 500 F / -40 to 260 CViton O-rings-40 to 435 F / -40 to 222 CPTFE seals-320 F / -195 C @ full rating to400 F / 204 C @1200 psi / 82.7 BarSoft SeatsThe soft seat is used in applications requiring ANSIClass VI 'bubble-tight' shutoff. The design consists of anelastomer sandwiched between two metal pieces. Theassembled soft seat is interchangeable with the hardseat for a given size and pressure rating. Inserts can beconstructed of PTFE; therefore, the maximum temperature should be below 350 F / 177 C at 1000 psi / 68.9Bar. For temperatures up to 400 F / 204 C, inserts ofPEEK material can be used to 1500 psi / 103 Bar.Soft Seat RingInsertInsert RetainerE0053* Multiple component ring; requires a hardened sleeve material.(1) Standard metal seals have two grooves (seals) in the plug.Flowserve Corporation, Valtek Control Products, Tel. USA 801 489 8611Figure 17: Typical Soft Seat Configuration11

Valtek Mark One-PowerMaterials of ConstructionTable VI: Body Materials1Sizes/2 – 48 inch; Class 150 thru 600/2 – 24 inch; Class 900 thru 25001/2 – 12 inch; Class 4500Globe, angle, 3-way, expandedoutlet, Y-bodyClass 150, 300, 600, 900, 1500,2500, 4500 and special classesCarbon steel, chrome-moly (C5,WC6, WC9, WC12), 316 stainless steel, others as requestedButtweld, Socketweld, Threaded,Integral or Separable Flange1FormsANSI RatingsMaterialsEndConnectionsTable X: GuidesTypeMaterialsDouble-top stemBronze, Alloy 6, Graphite, PTFE,other materials as requiredTable XI: GasketsTypesSpiral wound: 304, 316 S.S.,INCONEL, non-asbestos; GraphiteFlat: PTFE, glass-filled PTFETable XII: ActuatorsTypesDouble-acting cylinder with positivefail-safe spring action,Manual nder: 25, 50, 100 square inch(standard); 200, 300, 400, 500,600 square inch (optional)Manual handwheel: 9, 12, 18,24-inch diameterSide-mounted: continuouslyconnectedTop-mounted: continuouslyconnected, push-only, limit stopsCylinder: anodized aluminum, steelPiston: anodized aluminumActuator stem: 416 stainless steelYoke: ductile ironO-rings: Buna N, EPDM, Viton Air-to-open, Air-to-close(field reversible)Table VII: Bonnet MaterialsTypesStandard, standard extension,special length extensionSeparableSame as bodyFlangeMaterialsTable VIII: optional)Standard, Twin seal, Vacuum sealAFP/INCONEL wire, Graphite,Guard, SureGuard (XT),V-ring, Braided PTFE,Glass-filled PTFE V-ringLubricator w/ or w/o integralisolation valveSizesAuxiliaryMaterialsActionTable IX: TrimCharacteristics Equal percentage, Linear,Quick openMaterials416, 420, 440C, 316 S.S., alloysHard FacingsMaterials: Alloy 6 & 21,#5 Colmonoy , Ultimet Types: seat surface, full contour,full bore, lower stem guide areaSoft SeatPTFE, FEP, KEL-F , Polyurethane,PEEKPressureSizes: 2-inch and larger,balancedSeal types: elastomer, metal12Table XIII: PositionerTypesInput tsActionPneumatic, Electro-pneumaticElectro-pneumatic: 4-20, 10-50 mAPneumatic: 3-15, 3-9, 9-15, 6-30 psi0-1, 0-0.6, 0.6-1, 0.4-2.1 Bar40-150 psi / 2.8-10.3 Bar(no supply regulator required)-20 to 185 F / -30 to 85 C (std.)-50 to 250 F / -45 to 121 C (opt.)Stroke range, zeroAir-to-open, Air-to-close(field reversible)Flowserve Corporation, Valtek Control Products, Tel. USA 801 489 8611

Valtek Mark One-PowerSevere Service TrimsSevere ServiceTrims (Tiger-ToothTM, MegaStreamTM,ChannelStreamTM, and CavControlTM) can be designed intomost Valtek Mark One-Power control valves. This featureexemplifies the versatility of Valtek control products.Tiger-Tooth trim eliminates cavitation in liquid services and reduces noise up to 30 dBA in gaseousservices.MegaStream trim is an economical choice for reducing noise by up to 28 dBA in gaseous services.ChannelStream (above) trim in l