Control Valve Technical Specification

1 Control Valve Technical SpecificationControl ValveTechnical Specification Control Valves Practical Guides for Measurementand Control edited by Guy Borden, Jr. and Paul , 1998 edition published by : Control Valve Technical Specification 2000 by CCI. All Rights Reserved. This document has been produced by Control ComponentsIncorporated, Rancho Santa Margarita, California based on subjects presented in the ISA Guide "ControlValves - Practical Guides for Measurement and Control " edited by Guy Borden, Jr. and Paul G. Friedmann,1998 edition published by ISA and other published sources. The use of the letters ISA in thisspecification does not constitute an endorsement of this Specification by the InstrumentSociety of Valve Technical Specification5 Throughout this Specification , where the word shall is used to define a requirement,Seller must comply with the requirements. Where the word should is used todefine a requirement, Seller may select an alternative and advise Buyer ScopeThis Specification prescribes the minimum mandatory requirements governing thedesign, sizing, and selection of Control Equipment and services furnished by the Seller shall Design, fabrication, testing and delivery of all valves, complete withactuators and accessories to meet the requirements of this Specification andthe Control Valve data All interconnecting instrument tubing and fittings between the valveactuator, positioner, and filter Any special tools required for assembly, disassembly Valve drawings and calculations, including outline dimensions, weights,circuit diagrams, section drawings, part lists and Installation, operation, and maintenance manuals, including instructionsfor any Recommended spare parts Equipment and services furnished by the Buyer shall Receiving.

2 Unloading, storage, and installation of all equipment suppliedby Electrical wiring for power and signals for position indicating lights,solenoids, and/or Control All external piping, tubing, valves, and fittings, except as specified tobe furnished by the Conflicts and Any conflicts between this Specification and other applicable industrystandards, codes, and forms shall be resolved in writing by the Seller shall direct all requests to deviate from this Specification in writing tothe Buyer, who shall follow internal company procedure and forward such requestto the Engineering Manager, Instrumentation and ValveTechnical Specification63 ReferencesThe selection of material and equipment, and the design and construction of theequipment covered by this Specification shall comply with the applicable edition ofthe references in effect at the time of the Purchase Order and as notedthroughout this The International Society for Measurement and ControlISA GuideControl Valves, Practical Guides for Measurement and ControlISA Forms for Process Measurement and ControlInstruments, Primary Elements and Control ValvesISA Equations for Sizing Control ValvesISA Valve TerminologyISA Flow Characteristic and Rangeability of Control ValvesISA Valve Aerodynamic Noise PredictionISA for Evaluating Control Valve American Society of Mechanical EngineersASME Threads, General Purpose (inch)

3 ASME Pipe Flanges and Flanged FittingsASME and End-to-End Dimensions of ValvesASME Gaskets and Grooves for Steel Pipe FlangesASME Flanged, Threaded, and Welding EndASME PipingASME Plant and Petroleum Refinery PipingASME VIIIR ules for Construction of pressure Vessels Division Fluid Control InstituteFCI 70-2 Control Valve Seat National Association for Corrosion Control (where applicable)NACE MR0175 Sulfide Stress Cracking Resistant Metallic Materials forOil Field International Electrotechnical CommissionIEC 534-8-3 Control Valve Aerodynamic Noise Prediction Manufacturer s Standardization SocietyMSS-SP-61 pressure Testing of Steel TerminologyThe terminology and nomenclature used in ISA , Control ValveTerminology , and other ISA standards apply to this Valve Technical Specification74 Control Valve ApplicationsSeller shall select Control Valve design based on the requirements of theapplication, process operating conditions, and this ApplicationsApplications, common names and uses, and their key attributes covered underthis Specification are defined in Chapter 12 of the ISA Guide, Control Valves,Practical Guides for Measurement and Control and are summarized Process Control /Feed RegulationApplicationCommon Names and UsesFlow ControlFCV, ThrottlingLevel ControlLCV, Deareator.

4 Heater DrainPressure ControlPCV, InjectionPressure ReductionPRVFlow RegulationFeed Regulator, Gas RegulatorKey attributes for process Control /feed regulation applications are accuracy ofcontrol resulting from small signal changes, and high rangeability resultingfrom increased pressure differentials that exist across the Control valveduring start-up, shutdown, and low-load process conditions. Seller shallselect Control valves that meet these Continuous LetdownApplicationCommon Names and UsesAttemperationSprayBlowdownBDVFlow ControlFCV, Mixing, Steam SupplyChokeInjection, Withdrawal, Re-InjectionLetdownRich Amine, Drum, DrainLevel ControlLCV, Flash Tank, Separator LCVP ressure ControlPCV, Sootblower, Steam, ReducingPressure RegulationPRV, Steam SupplyThe key attribute for continuous letdown applications is accuracy of shall select Control valves that meet this Intermittent LetdownApplicationCommon Names and UsesAnti SurgeLoad RejectDumpAtmospheric Dump, Condenser Dump,Overboard DumpAuxiliaryAux.

5 SteamExtractionGas Withdrawal, Cavern WithdrawalReliefPRVB lowdownBDV, Steam Vent, Gas VentFlareGas to FlareStart-UpBypassTurbine BypassPRDSI njectionGas Injection, Steam InjectionLetdownDepressurizingpp. 417-419pp. 416-417pp. 412-415 Control ValveTechnical Specification8 Key attributes for intermittent letdown applications are tight shut-off and faststroke speeds. Seller shall select Control valves that meet these RecirculationApplicationCommon Names and UsesAnti SurgeCompressor Recycle, Spillback, Kickback, Surge ControlBypassStart-up, Vent, Turbine BypassRecirculationMini-flow, Leak-off, BFP RecirculationDumpOverboard DumpReturnLetdownKey attributes for recirculation applications are tight shut-off, anti-cavitationand/or low noise trim, and pipe vibration elimination. Seller shall select controlvalves that meet these Process Operating Process DataFor each Control Valve , Buyer shall specify the process data for the followingthree flow conditions as a minimum: Normal Flow Rate, Maximum Flow Rate,and Minimum Flow Normal Flow RateThis flow condition is generally referred to as the design flow or materialbalance Maximum Flow RateThis flow condition shall be consistent with the plant or equipmentoperational maximum flow condition.

6 The maximum flow condition isgenerally the governing case for required maximum Cv Minimum Flow RateThis flow condition shall be consistent with the plant turndownrequirement or equipment turndown capability. The minimum flowcondition generally subjects the Control Valve to the highest differentialpressure condition. The minimum flow conditions are generally thegoverning case for the required trim shall also specify the minimum and normal flow conditions for controlvalve services identified with normally no flow as well as the required flowconditions during non-normal plant operating conditions such as start-up,venting, depressurizing, shall provide sizing calculations for all specified flow Data SheetsIndividual Control Valve Specification requirements shall be specified by Buyerand/or Seller on ISA Form data sheet (see Appendix A) or Seller 420-422pp. 486-487 Control Valve Technical Seat LeakageSeat leakage classification shall be in accordance with FCI 70-2 or MSS-SP-61.

7 The leakage class shall be determined by the service application. Soft-seated valves shall not be applied in services with design temperatureconditions over 230 C (450 F) or in flashing liquid problems are commonly related to insufficient seat loading. While acontrol Valve with insufficient seat loading may pass a specified leakage testafter it is manufactured, the same Valve will not meet the specified leakage rateafter it has been subjected to thermal distortion, flashing, or erosive following minimum seat load requirements (after hydraulic loads, springloads and friction loads are considered) shall apply:Class I IIIPer Seller s RecommendationClass kgf/mm (300 lbf/in) of seat ring circumferenceClass kgf/mm (500 lbf/in) of seat ring circumferenceClass VIPer Seller s kgf/mm (1000 lbf/in) of seat ring circumferenceSeat ring circumference is defined as the line of contact between the plug andthe seat when the Valve is in the fully closed maximum shut-off differential pressure shall always be calculated andspecified for the selected Control Valve .

8 For all metal-to-metal shut-offapplications equal to or exceeding FCI 70-2 Class IV requirements, actuatorload calculations shall be provided. Calculations are required to show theminimum load to be applied to the plug-seat arrangement for meeting therequired shut-off Control Valve Control Valve SizingEach Control Valve shall be sized and selected to provide reliable operation andcontrol at the specified operating and design conditions. Control Valve sizing shallgenerally be based on ISA , Flow Equations for Sizing Control Valves .Seller may deviate from the ISA formulas provided that the reason is detailed inthe Technical shall select and size the Control Valve and actuator assembly andaccurately evaluate the minimum trim performance calculations for all operating conditions shall be provided. Thecalculation basis and results shall be shown for manual or computer Cv Capacity (Cv Required)The selected Control Valve trim capacity (Cv selected) should meet An equal percentage trim shall operate below 95% travel atmaximum 274-275pp.

9 112-161 Control ValveTechnical A linear trim and quick opening trim shall operate below 90%travel at maximum Cv capacity required to meet above criteria is referred to as Cvrequired . The actual Cv capacity of the Valve is referred to as the Cvselected . Specific applications may require an over-sized Cv capacity,which shall be specified by the Piping Geometry Factor, FPFor valves mounted between pipe reducers or other pipe fittings, the calculatedvalve capacity shall be corrected for a decrease in Valve capacity conformingto ISA The piping geometry factors FP, Control Valve correction factor,calculated FLP and/or XTP factors shall be specified by the Body SizeControl Valve bodies with reduced trims shall be considered for applicationswith the following conditions: pressure drop in excess of 5170 kPa (750 psi) Gas/vapor outlet velocities in excess of Mach High noise exceeding 85 dBA Choked flow Flashing exceeding 5% weight of liquid being vaporized Erosive fluids Future capacity increase is anticipatedIn all cases, the Control Valve nominal body size shall not exceed the nominalline Minimum RangeabilityThe installed rangeability (actual available rangeability) of each Control valvein the process system shall meet all flow conditions specified.

10 The specifiedminimum flow condition shall be fully Control Valve Minimum RatingThe Valve shall be rated to meet the design pressure and design temperatureof the application according to an internationally recognized flanged valves, the Valve body rating shall never be lower than the flangerating. The flange rating for Valve bodies smaller than 16-inch nominal sizeshall be minimum ASME Class 300. Flange rating for Valve bodies 16-inchnominal size and larger shall be minimum ASME Class MaterialsControl Valve body materials shall meet, or exceed, the requirements ofthe application. Body and trim materials shall meet the temperaturerequirements. NACE MR0175, Sulfide Stress Cracking ResistantMetallic Materials for Oil Field Equipment shall be applied for allmaterials in sour fluid 107pp. 363-370 Control Valve Technical Specification11 Trim materials shall be selected to withstand corrosion, erosion and wearunder severe service conditions.