Control Valve Technical Specification
Throughout this specification, where the word "shall" is ud to define a requirement, Seller must comply with the requirements. Where the word "should" is ud to define a requirement, Seller may lect an alternative and advi Buyer acco rdingly.
外币账户1 Scope
This specification prescribes the minimum mandatory requirements governing the design, sizing, and lection of control valves.
1.1 Equipment and rvices furnished by the Seller shall include:
1.1.1 Design, fabrication, testing and delivery of all valves, complete with actuators and accessories to meet the requirements of this specification and the control valve data sheets.
1.1.2 All interconnecting instrument tubing and fittings between the valve actuator, positioner, and filter regulator.
1.1.3 Any special tools required for asmbly, disasmbly and maintenance.
1.1.4 Valve drawings and calculations, including outline dimensions, weights, circuit diagrams, ction drawings, part lists and materials.
金泰希1.1.5 Installation, operation, and maintenance manuals, including instructions for any sub-suppliers.
1.1.6 Recommended spare parts lists.
1.2 Equipment and rvices furnished by the Buyer shall include:
1.2.1 Receiving, unloading, storage, and installation of all equipment supplied by Seller.
1.2.2 Electrical wiring for power and signals for position indicating lights, solenoids, and/or control stations.
1.2.3 All external piping, tubing, valves, and fittings, except as specified to be furnished by the Seller.
2 Conflicts and Deviations
2.1 Any conflicts between this specification and other applicable industry standards, co des, and forms shall be resolved in writing by the Buyer.
2.2 Seller shall direct all requests to deviate from this specification in writing to the Buyer, who shall follow internal company procedure and forward such request to the Engineering Manager, Instrumentation and Control.
清炒山药片3 References
The lection of material and equipment, and the design and construction of the equipment covered by this specification shall comply with the applicable edition of the references in effect at the time of the Purcha Order and as noted throughout this specification.
3.1 The International Society for Measurement and Control
ISAGuide Control Valves, Practical Guides for Measurement and Control
ISA S20.50 Specification Forms for Process Measurement and Control
Instruments, Primary Elements and Control Valves
ISA S75.01 Flow Equations for Sizing Control Valves
ISAS75.05 Control Valve Terminology
ISA S75.11 Inherent Flow Characteristic and Rangeability of Control Valve ISA SP75.17 Control Valve Aerodynamic Noi Prediction
ISARP75.23 Considerations for Evaluating Control Valve Cavitation
3.2 American Society of Mechanical Engineers
ASME B1.20.1 Pipe Threads, General Purpo (inch)春读音
ASME B16.5 Steel Pipe Flanges and Flanged Fittings
ASME B16.10 Face-to-Face and End-to-End Dimensions of Valves
ASME B16.20 Ring-Joint Gaskets and Grooves for Steel Pipe Flanges
ASME B16.34 Valves - Flanged, Threaded, and Welding End
ASME B31.1 Power Piping
怎样充话费
ASME B31.3 Chemical Plant and Petroleum Refinery Piping
ASME VIII Rules for Construction of Pressure Vesls 一 Division 1
3.3 Fluid Control Institute
FC170-2 Control Valve Seat Leakage
3.4 National Association for Corrosion Control (where applicable)
彩泥作品NACEMR0175 Sulfide Stress Cracking Resistant Metallic Materials for Oil Field Equipment 3.5 International Electrotechnical Commission
IEC 534-8-3 Control Valve Aerodynamic Noi Prediction Method
3.6 Manufacturer's Standardization Society
MSS-SP-61 Pressure Testing of Steel Valves
3.7 Terminology
The terminology and nomenclature ud in ISA S75.05, "Control Valve Terminology", and other ISA standards apply to this specification.
4 Control Valve Applications
Seller shall lect control valve design bad on the requirements of the application, process operating conditions, and this specification.
4.1 Applications
Applications, co mmon names and us, and their key attributes covered under this specification are defined in Chapter 12 of the ISA Guide, "Control Valves, Practical Guides for Measurement and Control" and are summarized below:
4.1.1 Proce ss Control/Feed Regulation
Applilication Common Names and Us
Flow Control FCV, Throttling
Level Control LCV, Deareator, Heater Drain
Pressure Control PCV, Injection
Pressure Reduction PRY
Flow Regulation Feed Regulator, Gas Regulator
Key attributes for process control/feed regulation applications are accuracy of co ntrol resulting from small signal changes, and high rangeability resulting from incread pressure differentials that exist across the control valve during start-up, shutdown, and low-load process conditions. Seller shall lect control valves that meet the attributes.
4.1.2 Continuous Letdown
Applilication Common Names and Us
Attemperation Spray
Blowdown BDV
Flow Control FCV, Mixing, Steam Supply
Choke Injection, Withdrawal, Re-Injection
Letdown Rich Amine, Drum, Drain
Level Control LCV, Flash Tank, Separator LCV
Pressure Control PCV, Sootblower, Steam, Reducing
Pressure Regulation PRY, Steam Supply
T he key attribute for continuous letdown applications is accuracy of control. Seller shall lect control valves that meet this attribute.
4.1.3 Intermittent Letdown
Application Common Names and Us
Anti Surge Load Reject
Dump Atmospheric Dump, Condenr Dump,
Overboard Dump
Auxiliary Aux. Steam
Extraction Gas Withdrawal, Cavern Withdrawal Relief
Blowdown BDV, Steam Vent, Gas Vent
Flare Gas to Flare
Sturt-up Bypass
rbine Bypass PRDS
Injection Gas Injection, Steam Injection
Letdown Depressurizing
爱德华的奇妙之旅
Key attributes for intermittent letdown applications are tight shut-off and fast stroke speeds. Seller shall lect control valves that meet the attributes.
4.1.4 Recirculation
Application Common Names and Us
Anti Surge Compressor Recyc1e, Spillback, Kickback, Surge Control Bypass Start-up, Vent, Turbine Bypass
Recirculation Mini-flow, Leak-off, BFP Recirculation
Dump Overboard Dump
Retum
Letdown
Key attributes for recirculation applications are tight shut-off, anti-cavitation and/or low noi trim, and pipe vibration elimination. Seller shall lect control valves that meet the attributes.
4.2 Process Operating Conditions
4.2.1 Process Data
For each control valve, Buyer shall specify the process data for the following three flow conditions as a minimum: Normal Flow Rate, Maximum Flow Rate, and Minimum Flow Rate.
4.2.1.1 Normal Flow Rate
This flow condition is generally referred to as the design flow or material balance flow.
4.2.1.2 Maximum Flow Rate
This flow condition shall be consistent with the plant or equipment operational maximum flow condition. The maximum flow condition is generally the governing ca for required maximum Cv capacity.
4.2.1.3 Minimum Flow Rate
This flow condition shall be consistent with the plant turndown requirement or equipment turndown capability. The minimum flow condition generally subjects the control valve to the highest differential pressure condition. The minimum flow conditions are generally the governing ca for the required trim pef ormance.
Buyer shall also specify, the minimum and normal flow conditions for control valve rvices identified with "normally no flow" as well as the required flow conditions during non-normal plant operating conditions such as start-up, venting,
depressurizing, etc.
Seller shall provide sizing calculations for all specified flow conditions.
4.2.2 Data Sheets
Individual control valve specification requirements shall be specified by Buyer and/or Seller on ISA Form S20.50 data sheet (e Appendix A) or Seller's equivalent.
4.2.3 Seat Leakage
Seatleakage c1assification shall be in accordance with FCI 70-2 or MSS-SP- 61. The leakage class shall be determined by the rvice application. Soft- ated valves shall not be applied in rvices with design temperature conditions over 230 ° C (450 ° F) or in flashing liquid rvices.
寻秋Leakage problems are com monly related to insufficient at loading. While a control valve with insufficient at loading may pass a specified leakage test after it is manufacture , the same valve will not meet the specified leakage rate after it has been subjected to thermal distortion, flashing, or erosive rvice.
The following minimum at load requirements (after hydraulic loads, spring loads and friction loads are considered) shall apply:
Class I 一 III Per Seller's Recommendation
Class IV 5.4 kgf/mm (300 Ibf/in) of at ring circumference
ClassV 8.9 kgf/mm (500 Ibf/in) of at ring circumference
ClassVI Per Seller's Recommendation
MSS-SP-61 17.9 kgf/mm (1000 Ibf/in) of at ring circumference
Seat ring circumference is defined as the line of contact between the plug and the at when the valve is in the fully clod position.
The maximum shut-off diff erential pressure shall always be calculated and specified for the lected control valve. For all metal-to-metal shut-off applications equal to or exceeding FCI 70-2 Class IV requirements, actuator load calculations shall be provided. Calculations are required to show the minimum load to be applied to the plug-at arrangement for meeting the required shut-off specifications.
5 Control Valve Selection
5.1 Control Valve Sizing
Each control valve shall be sized and lected to provide reliable operation and control at the specified operating and design conditions. Control valve sizing shall generally be bad on ISA
S75.01, "Flow Equations for Sizing Control Valves". Seller may deviate from the ISA formulas
