engineered control valves - v & p solutions

SchuF www.schuf.com Engineered Control Valves

Fetterolf [email protected] +49 6198 571110; +1 843 881 3345; +353 21 4837000 SchuF

EngineeredControlValvesfor critical service



For over 60 years, SchuF’s control valveshave performed in the most arduous tasksin the Chemical, Petrochemical, Refining,Mining and Power industries. The valves areavailable with angle and in-line bodies.SchuF also offers a wide selection ofspeciality control valves ranging frommultistage angle to multiport divertervalves. They include high pressure, hightemperature let down valves, boiler feedand start up valves, disc and piston (ram)drain valves with contoured discs and rams,distributor control valves and bellowssealed valves.

Unrivalled experience - 3 phase slurries.Our designs reduce or eliminate flashing inthe valve before the seat, thus improvingthe life of body and trim. The disc openingdesign opens into the downstream vessel,ensuring that flashing takes place in an„infinite“ pipe preventing choking andreducing fluid speed. Over the past 20 yearsSchuF has perfected it’s proprietary Cvcalculation programme, which is unique init’s abilitiy to handle 3 phase flow as well ashigh viscosity, non Newtonian fluids.

Patented InnovationSchuF’s patented x3 bell curve as analternative to linear, equal % or on /offcharacteristics, offers better controllabilityaround operating conditions.

Industries servedOur valves are used as let down, level andflow control, three way mixing anddistributive control for PTA, Polymers (PET& PBT, PU PVC etc), Coal and Heavy oilupgrading, gasification and liquefaction, salt& brine, Urea, metal slurries, steam handlingand many more.

FeaturesThe trim is single or multi-stage, with flow toopen or close. On/off, hollow piston and cagetrim are also available.

SchuF’s strengths include flexibility of designand construction. We have produced controlvalves in all stainless steels, high Nickelalloys, Titanium and Zirkonium as well asPTFE and glass linings. SchuF uses specialsurface coatings and multiple spindle guidingto improve the resistance against vibrationsand erosion. SchuF also offers solid TungstenCarbide and Ceramic trims.

Most control valves come equipped withpneumatic diaphragm actuators (available ina fire-safe version) and piston actuators,while hydraulic and electric actuators areutilised for high pressures and specificcontrol regimes.

CFD simulationExtensive experienceexists allowingdetailed modelling tooptimise body design.

Detailed InformationOur main models are shown in specialproduct fliers.

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Pressure and Level Control, 74BSOriginally designed for PTA 3 phase slurry service thesevalves open into the downstream vessel to eliminatechoking and cavitation. The accelerating body designprevents „in body“ flashing, the single piece disc andspindle with spindle protector stops metal fatigue andspindle bending. The valves are used in multi-stagereactor or crystalliser arrangements to control the levelor pressure in the upstream unit. Optinalelectrohydraulic actuators (below) eliminate stickingand hunting.

Multistage Let Down, 74MSMulti-stage let-down distributes the pressure across twoor more stages, enhancing the life of the trim. Thesevalves are not suitable for high solid content or largeparticles as these can clog the flow path in the seat. Inthe cracking process unconverted oil or residue isdepressurised through a multi-stage control valve inwhich the vapour fraction flashes out according to itsproperties. This valve may have inlet conditions of 100°C/100~200 bar. A special material venturi is available afterthe last seat if cavitation is unavoidable.

High Pressure Angle Valve for UreaHigh pressure (200bar working pressure at 200°C) areextensively used in Urea plants. SchuF delivers anglevalves for this service with manual or pneumatic actuation,with on/off or control trim, as reactor or angle valves.

Severe Service Let Down Applications:

Let Down, 74CSIf piping considerations prohibit a disc opening valve,the 74CS offers a disc which opens into the valve. Theeffects of cavitation can be minimised by the use ofsuitable trims (e.g. stellites, ceramics and special grainTungsten Carbides), optimised trim design with easyto replace trim and SchuF’s impulse control modus.Examples include PTA recycling (above) and direct coalliquefaction where the residue is let down progressivelyfrom pressures over 200 bar in the HHP separator tovacuum in the distillation unit at temperatures up to500°C.



In-line Globe Control Valve, 72BSSchuF supplies many in-line control valves featuring stuffing box orbellows seal, mostly with special materials or trim such as one with anoise reducing cage.

Engineered Control Valve Applications:

Y-Globe Control Valve, 50SRThe drawback of a globe control valveis the low capacity and high pressureresistance. The ball type control valveshave a limited life due to the ball’srotation wearing out the seal and needlarge actuators to overcome the hightorques. The y-globe valve’s flowcharacteristics come close to those ofa ball valve, and allow the use ofsmaller valves compared to a globevalve.It’s proven metal to metal seatquarantees a longer leak tight sealingperformance than the ball valve withsmaller actuators. A typical applicationis temperature control for a heatexchanger in a hydrocracker.

Vessel Drain ControlNormal flush mounted disc or ram bottomvalves can be customised and fitted withcontrol contours.

Cage Control ValveAn angle valve with a class VI shutoff and acage with stepped Cv that offers goodcontrollability at both very low and highflowrates is used here as an emergency ventcontrol for Hydrogen. The class VI shut offis especially important for valuablecommodities like hydrogen.

Solid Feed Control ValveSchuF supplies control valves to control the flow of dry powder feed carriedby gas even with high delta P. This is an example of gas carried coal feedflow control valve, designed for Shell, where control of the flow is a criticaland complex task. The coal must not settle in the valve and so certainminimum speeds of flow must be maintained. At these speeds the coal isabrasive and so special materials such as an tungsten carbide must beused to produce the valve.

Pump Recirculation ValveThese valves protect the pump fromoverheating. When required they create „aclosed loop“ for the pumps by feeding themin required flow back to the pump inlet.Applications include sea-water on anFPSO, C4 in a refinery, oil in a cracker, PTAslurry and coal slurry in a liquefaction plant.

Wafer Type Control ValveThese valves feature short as built lengths, yet theymaintain a high flexibility with an extremely widerange of Cv’s. Their short lengths mean they canbe flanged between two pipeline flanges, evenwhen fully jacketed. The examples shown here areused in the production of nylon andpolycarbonates.



Steam Conditioning Valve, 74DUSteam control valves control the pressure andtemperature of steam. Steam is generated at highpressures and temperatures to ensure high turbineefficiencies. The movement of the main stem regulatesthe pressure, the addition of water through the stemdesuperheats the steam. The further the valve opensthe greater the product throughput and the morecooling water is added.

Steam and related Applications:

Waste Heat Recovery ValveThis valve is a full bore 3-way steam mixingvalve. Hot flue gas from the melting furnacesare used to turn water into steam by boilers.Steam from these waste heat recovery boilersare transported and combined through a pipingnetwork to supply steam at high pressure,which is then passed through an existingturbine to generate electricity. The 3-way valveserves as a mixing isolation valve in the mainsteam header.

Start Up Valve for Steam GenerationAmong the uses for the energy inherent in the hightemperature flue gases from the furnaces of a Naphthacracker is the generation of steam. A normal control valveregulates the usage of steam, once the system is atpressure. In order to get the system up to pressure a valvemust handle a small flow across the full pressure drop(over 120 bar). The standard control valve cannot handlethe efficiently, so a parallel start-up valve is used until thesystem is up to operating pressure.

Gasoline Mixing Control ValveThis is an example of a gasoline mixing valve used in the oilrefining industry in hydrocracker control. It controls the mixingof gasoline from a fluid catalytic cracking unit (which is thenpassed through a heat exchanger) with crude gasoline. Itusually has a linear control contour.

Delayed Coking Lift Plug Switching Control ValveDelayed coking is a semi-continuous thermal cracking process. After beingheated in a coke furnace the coke feed (a liquid-vapour combination) ispassed through a coke drum. Delayed cokers are designed as pairs sothat one can be cleaned with the other remaining in operation. A four wayswitching valve is required here to allow coke feed into whichever cokedrum is active. During start up, shut down or an emergency, the valve canalso bypass both drums, through the third outlet. The lift plug switchingvalve uses much less steam than a ball switching valve, shows no gapsbetween plug and body, minimises spare parts and maintenance timeand cost. It can be supplied as a complete unit with isolation valves andcontrol panel.



Monomer & Polymer Control Valve Applications:

Monomer Feed ValveDisc control valves are used to regulatethe level in PVC reactors. For PET, PBTetc, control valves are used to regulatethe flow into the esterification andpolymerisation reactors. For vacuumservice, bellows are generally used. Asthey are susceptible to failure in acrystallising and polymerisingenvironment, SchuF recommendsexternal bellows. In these applications,weld-lip gaskets can further enhance thevacuum safety of the system.

Polymer Additives Injection ValveThese valves were developed to allow continuous polymer plantsproducing, for example PET, to customise their product. These valvesallow small amounts of additives and catalysts, such as Titaniumdioxide to be injected into the line and distributed evenly into thepolymer stream. For accurate and uniform injection of very smallquantities, an automated high frequency, minimal volume valve isused.

Polymer Flow Control ValveIn direct spinning polymer plants a chip line is oftenadded to take the overflow. It is important that thepressure at the spinning heads is constant to ensurelong, even strands. In order to ensure this the flow tothe chipper line is varied using a flow control valve. Inthe different examples shown here either a traditionallinear control contoured disc as a branch valve, or arotating ram with special contoured tip or a variablerestriction length is used. These valves can becombined with multiport diverter valves to control thepressure in many different lines.

Injection, Stripping & Spray Rinse ValveIn many processes unwanted impurities or remnants(such as unpolymerised monomers in PVC andPolyurethanes or Solvents in Paints and Coatingsuspensions) are stripped from the batch by theinjection of steam. The ram tip is specially adapted toeach vessel as well as the required flow conditions,optimising the spray pattern.

Spray rinse valve clean the reactor after each batch.This is especially useful in closed reactor technology.



General Specifications:Valve sizes1/2“ to 36“ (DIN 15 to 900mm)

RatingClass 150 to 2500# ASME, DIN or JISButt weld endsFlanged ends in RF, RTJ, LR or LM/LF styleHub and clamps from Grayloc or Securamax

Inlet temperatures and pressuresConsistent with applicable rating according toASME B16.34

MaterialsBodyWCB, WC6, WC9, Cr-Mo SteelCF3, CF3M, CF8, CF8C, CF8M, CG8MDuplex, Incoloy, Inconel, Hastelloy & TitaniumLining / SleevesGlass, PTFEColmonoy, Stelliting, ChromingTungsten Carbide, TiN, CanadisingTrim420, 316, 316L, 321 st.st.SAF 2205, Inconel, TitaniumStellite, Tungsten Carbide, CeramicsJacketingFull or partial, C.St., st.st. or Titanium

In this general brochure we hope to presenta small cross-section of the type of productswe have already supplied. Please do not feelconstrained - we can supply you with manymore special designs. Chances are that wemay have already solved your problem!

Table of Cvs available: Valve Size Seat diam Cvs min Cvs max

3-5 0,1 1 1“-1 1/2“ 6-10 1 6 DN 25-40 10-15 6 10

15-20 10 20

2“ DN 50 20-40 20 50 3“ DN 80 50-75 60 240 4“ DN 100 70-90 140 300 6“ DN 150 80-135 180 500 8“ DN 200 100-175 250 1000 10“ DN 250 150-200 500 1250 12“ DN 300 14“ DN 350 200-300 750 3500 16“ DN 400 18“ DN 450 20“ DN 500 24“ DN 600 300-400 2700 5000 36“ DN 900

Calculating required Cv SchuF calculates the requirement for the three phases separately. For liquids we first check for cavitation. Cavitation will occur if ( )vc PPK −= 1*8.0 is less

than û3 . If

−−=>

cP

vP0.280.96*vP1Pcû3û3 ,

choked flow will occur and cû3 should be used instead of û3 in the formula for liquids:

)*1000*()*1000(*

P

W

PQKvf ∆

=∆

=ρ

ρ

For Gases we use:

∆

=

∆

=

MPP

ZTW

PP

MZTQKvg **

**

110*

***

2600 1

1

1

1

and for steam:

∆

=

P

vWKvw *

32

Note that for gas or liquid use /2û3û3 1= as a max.

In all three cases note that ** *156.1 vv KC = ; We now add to get total required Cv:

vwvgvfv CCCC ++=

Note that these formulas may give nonsensical results in case of boiling liquids. SchuF has developed a technique to modify and eliminate this phenomena.

Flow Coefficientssingle stage 1 to 5000multi-stage 1 to 350, cage 1 to 300

Flow CharacteristicLinear, Equal percentage, x3 or bell curve

Flow DirectionFlow to open or close

Positioner SelectionAs per customer specification.E.g. Siemens PS2 Smart, SMC i/p positioner

Actuator SelectionPM multi-spring diaphragmm actuator in st.st., C.St. or Aluminium casingPD double acting cylinder actuator in steel casingPE single acting cylinder actuator in steel casingEM electric actuatorHY hydraulic actuatorEH electro-hydraulicKU bevel gearLM pneumatic motor

Available valvesAngle, line, wafer, T-piece, multiportInlet/oulet angles of 180, 90, 60 or 45°

SchuF FETTEROLF Worldwide

Fetterolf Corporation, Inc. USA

[email protected]

SchuF USA [email protected]

SchuF Armaturen und Apparatebau GmbH

SchuF Chemieventile

Vertriebs GmbH & Co KG Germany

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SchuF Valve Technology, GmbH

Ireland

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Your Local Agent

SchuF Specialty Valves India Pvt. Ltd.

India

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Fetterolf SchuF do Brasil Ltda

Brazil

[email protected]

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