T ECHNICA L BU L L E TINValtek Mark OneControl Valves Experience In Motion

Valtek Mark One Control ValvesBody assemblyHigh-thrust cylinder actuator:Three standard sizes covermost applications. Eachis easily reversible andfeatures exceptional stiffness,repeatability and low hysteresis.Fail-safe springOHeavy guiding: Two widelyspaced guides on largediameter stem. Plug doesnot guide in retainer.SHigh performance:Positioning accuracy to0.1% full scaleClamped-in seat ring:Valve may be disassembledquickly and easily byremoving bonnet bolts.Versatility: ANSI Class 600(PN 100) body used forANSI Class 150, 300 and600 (PN 16, 40, 100) ratingsthrough 4-in (DN 100)Figure 1: Valtek Mark One globe control valveThe Valtek Mark One globe control valve offers superiorperformance in liquid and gaseous services, while alsopermitting easy, fast and inexpensive maintenance.The spring-cylinder actuated Mark One valve providesstiffness and maintains high positioning accuracy, repeatability,controlled high speed and faithful response. The Mark Onevalve handles to 150 psig (10.3 barg) supply air and has thethrust to shut off against much higher fluid pressures.The Mark One valve is designed so the spring, supply airpres sure and fluid pressure combine to produce exceptionallytight shutoff. A self-aligning seat ring further enhances theshutoff capability.VLENTB0001-04 (AQ) June 2019The Mark One valve is typically double top-stem guided andcompletely avoids contact between the plug and seat retainer.Many globe valve maintenance problems can be traced tocage-guiding. The close metal-to-metal contact between thecage and plug often result in galling and sticking.The clamped-in seat and top-entry trim permits easy, quickmaintenance. Plus, with the Mark One valve’s high degree ofparts inter changeability, fewer inventory parts are required. Inaddition, the actuator is lighter, smaller and easier to handlethan comparable diaphragm actuators.The Valtek Mark One control valve is the industry choice fora simple, reliable, tough globe valve.2

Valtek Mark One Control ValvesAdvantages and featuresAdvantagesDesign lower total lifetime costVersatileTrim that does not stick or gallFeatures High interchangeability between sizes and other Valtek control productsValve design minimizes requirements for stocking spare partsRugged, heavy-duty parts provide extended lifeActuator design allows simple, easy maintenance Globe, angle, three-way and jacket styles offer multiple face-to-face standards Double-stem guiding located out of flow stream Generous clearance between plughead and seat retainer Eliminates galling associated with cage-guidingEasy, fast and inexpensive Top-entry servicingClamped-in seat ringEvenly compressed gasket — controlled gasket compressionSeparable flangesHigh degree of parts interchangeabilitySmall, lightweight designLeakproof when closed Self-aligning seat ringAssisted shutoff from fluid pressure, cylinder spring, cylinder pressureHigh-thrust, spring-cylinder actuatorSpring fails valve to desired position, pneumatics provide additional forceBuilt for toughest service Corrosion-resistant constructionHigh thrust overcomes high pressuresAnti-cavitation and noise-trim optionsHeavy-duty plug stemFactory Mutual approved as a fuel service valve (0.75–3 in/DN 20–80) Cylinder actuator smaller than most competitor actuatorsLower center of gravity than comparable actuatorsLighter weight means less pipe stress from static and dynamic loadsSeparable end flanges allow the valve to be installed in many orientationsand compensate for flange misalignment Stiff, high-thrust cylinder actuatorAccurate positioningHigh repeatabilityFaithful responseControlled, high-speed stroking actionCompact and easy to installReliable, predictable serviceVLENTB0001-04 (AQ) June 20193

Valtek Mark One Control ValvesComponentsAdjusting screwAdjusting screw gasketSpringSpring buttonPiston stem O-ringPiston retaining nutCylinderActuator stem spacerPistonActuator stem bushingPiston O-ringActuator stem O-ringYoke O-ringStem clampActuator stemOGland flangeUpper packingCylinder retaining ringStroke plateSYoke clampStem bellowsYokePacking spacerUpper stem guideBonnetUpper stem guide linerBonnet flangeBonnet flange boltingSeat retainerLower packingSeat ringBonnet gasketSeat ring gasketLower stem guideBodyLower stem guide linerHalf ringPlugEnd flangeFigure 2: Mark One control valveVLENTB0001-04 (AQ) June 20194

Valtek Mark One Control ValvesBody stylesFigure 3: Globe-style bodyFigure 4: Three-way bodyGlobe-style bodies feature smooth, streamlined, constantarea internal passages with no pockets, permitting highcapacity with minimum turbulence. They are designed withnearly constant wall thickness, providing lower weight andcost when manufactured in expensive stainless or alloy steels.Three-way bodies are used for either combining or divertingservices. Due to Flowserve’s excellent parts interchangeability,a standard globe valve easily converts to three-way servicewith the addition of a three-way adaptor, upper seat ring,two gaskets, three-way plug and longer bonnet flange studs.Figure 5: Angle-style bodyFigure 6: Steam-jacketed bodyExcept for the body and 1.5-in (DN 40) seat ring, the anglestyle Mark One valve is completely interchangeable with theglobe style; all other valve parts remain the same. For additionalbody protection, a venturi seat ring, extending to the outletflange, is available.VLENTB0001-04 (AQ) June 2019The steam-jacketed Mark One valve uses a standard globestyle body with oversized, blind flanges for a full jacket orstandard flanges for a partial jacket. The jacket is rated for150 psig (10.3 barg) and is equipped with a 0.75-in NPTsupply and drain connection.5

Valtek Mark One Control ValvesEnd connections, flangesand boltingMark One body facings come standard as raised face for eitherseparable and integral flanges. To achieve better sealing withmating piping, the flange face is machined with spiral groovedserration. Other optional facings include smooth face, flat face,ring-joint, large and small tongue, and large and small groove.Bonnet flangeboltingBonnet flangeSeparable end flangesInterchangeable separable flanges are standard for valve bodies0.5- through 4-in (DN 15–100) in ANSI Class 150, 300 and 600(PN 16, 40 and 100). With separable end flanges, an ANSI Class600 (PN 100) body can be adapted for ANSI Class 150, 300 or 600(PN 16, 40 and 100) service by simply changing the end flanges.Separable flanges are usually furnished in carbon steel formaximum cost savings, although stainless steel can be specifiedif needed.Bonnet flangeThe bonnet flange incorporates the same separable design as theend flanges and is normally manufactured in carbon steel; however,it can be specified in stainless steel when required.End flangeANSI Class 150(PN16)Body ANSIClass 600 (PN 100)Figure 7: Separable endand bonnet flangesBonnet flange boltingAll sizes use studs and nuts that are furnished in 304 and 316stainless steel, suitable for -253 C to 816 C (-423 F to 1500 F).These temperature limits are for maximum pressure permitted byANSI B16.34, latest edition.Table 1: End ConnectionsEnd ConnectionSeparable FlangeIntegral FlangeSteel and AlloysScrewed 160–400Valve SizeVLENTB0001-04 (AQ) June 2019Rating ClassS75.03S75.16S75.12ANSI Class 300(PN 40)ANSI Class 600(PN 100)Figure 8: End flangesS75.156

Valtek Mark One Control ValvesEnd connections, flangesand boltingThe Mark One valve is designed with the bonnet and seatring gaskets fully retained. Since the bonnet bottoms metalto-metal in the body, the bonnet gasket compression isdetermined by the depth of the gasket step on the bonnet,which is machined to provide the required gasket compression.Bonnet gasketSeat ringgasketWhen the bonnet is fully installed, force is transmitted throughthe seat retainer to secure the seat ring in position. The body,seat retainer and seat ring are all machined to close tolerancesto provide the proper gasket compression. Unlike the bonnet,the seat ring does not always bottom in the body, allowing thissmall clearance to compensate for manufacturing tolerancesand thermal expansion.Figure 9: Body gasketsTable 2: Gasket SpecificationsEnd ConnectionStandard GasketsAlternate GasketsTypeGasket MaterialFlatMaximum Gasket Temp. Minimum Gasket Temp. C F C FPTFE177350-130-200Spiral-wound3316 -3201FlatFEP204400-196-320Spiral-wound3316 S.S./Thermiculite 8161500-30-20Metal O-ringInconel X-7508161500-301-2011Lower temperature available upon request.2Limited to (427 C) 8000 F for oxidizing service.3Alloy spiral windings available upon request.Yoke clampsThe actuator is typically attached to the Mark One body assemblywith two precision-cast, stainless steel yoke clamps. In somecases, however, the actuator is bolted directly to the bonnet. Eachclamp has an inclined plane surface which, when bolted together,securely fastens the actuator yoke to the bonnet.Unlike conventional threaded clamps, the clamp design permitseasy removal, even under extremely corrosive conditions.Associated bolts and locknuts are supplied in plated carbonsteel, although stainless steel is also available when required.YokeclampFigure 10: Yoke clampVLENTB0001-04 (AQ) June 20197

Valtek Mark One Control ValvesBonnet typesStandard bonnetThe Mark One bonnet is usuallyconstructed of the same material asthe body and handles temperaturesfrom -30 C to 400 C (-20 F to 750 F).See Table 4 on page 10 for packinglimitations.Extended bonnetThe extended bonnet protects thepacking from excessive heat or cold,which may inhibit valve performance.The bonnet is constructed of carbonsteel for temperatures from -30 C to427 C (-20 F to 800 F) and of 304 or316 stainless steel for -100 C to 816 C(-150 F to 1500 F).Standard bonnetExtended bonnetCold boxextended bonnetFigure 11: Mark One bonnet typesCold box extended bonnetThe cold box extended bonnet permits stagnated, moderate temperature gas to form in the bonnet, which protects the packingfrom the service fluid. Typically manufactured from 304 or 316 stainless steel, it handles temperatures down to -253 C (-423 F).Standard construction consists of stainless steel bonnet flange and bolting.Mark One K-bellows seal(see Figure 12: Mark One with K-Bellows on page 9)The K-Bellows can be designed for virtually any processcondition. The externally pressurized, hydro-formed bellowsdesign is robust and reliable. Hydro-formed bellows aremanufactured from thin metal sheets that are rolled into a tubewith the edge of the tube fused together.The K-Bellows is welded to a seal at the top of the bonnet andstretches down the valve stem to the end where it is weldedjust above the plug head. The shroud-less design is popular inthe chemical industry.Bellows materials: Bellows materials should be selectedbased on the most difficult requirements for the application.For example, a bellows sealed valve installed in a dry chlorineservice should determine material selection based on moistureaccessing the system.A carbon steel, stainless steel or alloy body should be chosenwith Monel or Hastelloy C trim. A Hastelloy C bellows shouldalways be recommended. Even though Monel is available, itshould not be recommended. Monel is an excellent choice fordry chlorine, but does not do well against wet chlorine.VLENTB0001-04 (AQ) June 2019Bellows length: Bellows cycle life is related to the length of thebellows. The Mark One includes various bellows seal lengths.The K-Bellows can be designed with lengths that maximizecycle life for a specific application.Placement of the neutral position: The neutral position is theposition where the bellows is completely relaxed. The MarkOne K-Bellows is designed in the neutral position at 50% ofthe valve stroke. The cycle life of the bellows seal is extended,as it only absorbs 50% of the total valve stroke.Pressure limitations: ANSI pressure classes 150, 300, 600,900 and 1500 are standard. Higher-pressure bellows can beengineered upon request.Temperature limitations: The temperature limit depends onthe bellows type and material used. K-Bellows can operate attemperatures ranging from -80 C to 400 C (-90 F to 750 F).Size limitations: K-Bellows are typically available on valve sizes6 and smaller. Larger sizes can be designed upon request.NOTE: Bellows seals are designed for special service conditions and not tovalve’s design class; therefore, complete and accurate service conditionsmust be specified.8

Valtek Mark One Control ValvesUpper stem guide(Item nos. 86, 87)Packing(Item no. 88)Packing spacer(Item nos. 93, 94, 95)Bonnet(Item no. 40)Bonnet flange bolting(Item nos. 78, 114)Tell-tale tap(Item no. 42)Bonnet flange(Item no. 70)Upper bellows flange(Item no. 6)Anti-rotation pin(Item no. 6)Bellows assembly(Item no. 6)Upper flange gaskets(Item no. 58)Bellows housing(Item no. 5)Guide retainer(Item no. 83)Body bolting(Item nos. 108, 114)Guide housing(Item no. 31)Guide housing gaskets(Item no. 56)Lower guide liner(Item no. 82)Seat retainer(Item no. 30)Plug head(Item no. 50)Plug stem(Item no. 6)Seat gasket(Item no. 55)Seat ring(Item no. 20)Body(Item no. 1)Figure 12: Mark One with K-BellowsNOTE: Item numbers correspond directly to the valve’s bill of material.VLENTB0001-04 (AQ) June 20199

Valtek Mark One Control ValvesPacking and guidingPacking boxStandard Valtek packing boxes are deeper than most conventionaltypes, providing the following advantages:1. The spacing between the wiper set and the main upper packingset prevents contamination of the upper packing. The upper set ispositioned far enough away from the wiper set to avoid contact with anypart of the plug stem that has been exposed to the flowing medium. Thewiper set is designed to minimize the amount of fluid on the plug stem.2. Bonnets are designed to permit a wide variety of packing configurations,including a double set of packing, without changing bonnets.3. Two widely spaced stem guides, when used with the Mark Onevalve’s large plug stem diameter, provide exceptional guiding. The upperstem guide also acts as a packing follower; the lower guide is situatedclose to the plug head for additional guiding support, ensuring accuratealignment of plug and seat ring.4. Graphite-lined stainless steel guides provide superior guiding overwide temperature ranges and completely eliminate guide/stem galling.A variety of guides are available for various applications, including solidbrass, Alloy 6 and glass-filled PTFE-lined stainless steel.5. For standard and environmental packing systems, see technicalbulletin VLENTB0040-01.UpperguideTable 3: Temp.Maximum PressureGraphitelined SS***816 C(1500 F)-196 C(-320 F)1400 psig/96.6 barg to 2 in/DN 501000 psig/69.0 barg 3–4 in/DN 80–100850 psig/58.6 barg 6 in DN 150 and up148.9 C(300 F)260 C(500 F)816 C(1500 F)-198.3 C(-325 F)-253 C(-423 F)-253 C(-423 F)Glass-filledSolid BronzeWiperpackingsetLowerguideSolid Alloy 61400 psig/96.5 barg @ 60 F/15.5 CSame as bodySame as bodyTable 4: PackingBonnet TypeStandard**BonnetExtended**BonnetPacking MaterialService Fluid Temperature LimitationPTFE, PTFE/AFP and Glass-filled PTFE260 C260 C500 F500 FGraphite/AFP400 C750 FGraphite/AFP, Inconel wire400 C750 FGraphite***400 C750 FPTFE, PTFE/AFP and Glass-filled PTFE316 C600 FGraphite/AFP650 C1200 FGraphite/AFP, Inconel wire650 C1200 FGraphite***816 C1500 F*Temperatures assume environmental temperatureis less than 32 C (90 F); 8–12-in (DN 200–300)ANSI Class 150–600 (PN 160–400) and 3–12-in(DN 80–300) ANSI Class 900–2500 (PN 160–400)handles temperatures to 454 C (850 F).**ANSI B16.34 specifies acceptable pressuretemperature limits for pressure-retaining materials.Consult the factory for additional information.***Do not use graphite above 427 C (800 F) inoxidizing service such as air or oxygen. The useof graphite packing may require oversize actuatorsor heavier springs due to added friction.Cryogenic Extended Length**15, 18-in (38, 46 cm)PTFE-196 C-320 F24, 27-in (38, 46 cm)PTFE-253 C-423 FVLENTB0001-04 (AQ) June 201910

Valtek Mark One Control ValvesFlow characteristics, trim types100RISACARCH50Equalpercentage050% Flow100Quick-openQuick-open plugs are used for on-off service and are primarilydesigned to produce maximum flow TNREHEIN0Linear100INSTA% FlowLinear inherent characteristic produces equal changes in flowper unit of valve stroke, regardless of plug position. Linearplugs are used on those systems where the valve pressuredrop is a major portion of the total system pressure drop.TE50% Valve YINHERTYPICALEqual percentage is the characteristic most commonly usedin process control. The change in flow per unit of valve strokeis directly proportional to the flow occurring just before thechange is made. While the flow characteristic of the valvemay be equal per centage, most control loops produce aninstalled characteristic, which approaches linear when theoverall system pressure drop is large relative to that acrossthe valve.% FlowEqual percentage50% Valve Stroke100ICERISTRACTT CHANERINHE50050% Valve Stroke100Figure 13: Flow characteristicsTrim typesThree trim types are available. Standard full-area trim providesmaximum CV. Reduced trim is available in a wide variety ofsizes when lower CV values and large bodies are required.Integral trim uses a special seat machined into the bodyand an oversized plug to provide additional CV beyond thecapabilities of full-area trim.Mark One valves can be converted from one trim type toanother, since all seat rings and plugs with a given size andpressure class are completely interchangeable. Integral trimis available by removing the seat ring and changing the plug.Full areaReducedIntegralFigure 14: Typical trim typesVLENTB0001-04 (AQ) June 201911

Valtek Mark One Control ValvesStandard and pressure-balanced Plug sealsPlug ventPlugPlugPressurebalancedsleeveSeatringMark One valve trim is designed to avoid the difficulties associatedwith screwed-in seats and cage-guiding. The seat ring is clamped intothe body by the bonnet and seat retainer; thus, removal of the seat iseasy, even under extremely corrosive conditions.Unlike cage-guided trims that easily gall and stick, Mark One plugs aredouble-stem guided, avoiding contact between the seat retainer andplug. Because no contact is made with the plug, the retainer can beconstructed of stainless steel, rather than costly hard materials. Theflow characteristic is determined by the plug contour, rather than bythe opening in the retainer.Low-noise seat designs have been developed for better noise controlin standard Mark One valves.Metal seatsMetal-seated valves handle Class IV shutoff (ANSI B16.104, 1976 –FCI 70-2). This class calls for maximum permissible seat leakage of0.01% of rated valve capacity. All Valtek control valves are seat-leaktested after assembly and substantially lower in leakage than called forby this class. This exceptional seat tightness is obtained by aligningthe seat ring with the plug during assembly. Additional seat tightnessusing metal seats is available as an option.In high-pressure drop applications, pressure-balanced trim is used toreduce the thrust necessary to stroke the plug by reducing the trimoff-balance area. Because the pressure-balanced plug fits closely tothe retainer, this trim should only be used in generally clean services.Flow direction is under-the-plug for fail-closed and over-the-plugfor fail-open. The seal area less the stem area