+---
+title: Control Valves and Actuators
+category: Instrumentation & Controls / Field Instrumentation
+toc_depth: 3
+description: >
+ When to use: The automated final control element of a process control loop — modulating (throttling) control valves and the actuators and positioners that drive them — for industrial, process, and water/wastewater (WTP/WWTP) facilities. Covers globe, segmented-ball, eccentric-plug, and butterfly valves used for modulating control; pneumatic spring-diaphragm and piston actuators and electric actuators sized for continuous modulating duty; analog, HART, and digital/fieldbus valve positioners with diagnostics; and accessories (I/P transducers, solenoid valves, limit switches, position transmitters, volume boosters). Addresses valve sizing and flow-coefficient (Cv) selection per ANSI/ISA-75.01.01 / IEC 60534-2-1, inherent flow characteristic (linear, equal-percentage, quick-open), rangeability, choked flow, cavitation and flashing with anti-cavitation trim selection, predicted noise, fail-safe action (fail-open, fail-closed, fail-last), seat leakage class per ANSI/FCI 70-2, materials and trim, and stroke/calibration. Also covers electric (motorized) actuators on isolation valves (MOVs) where the actuator is the controls interface — open/close or modulate with position feedback to SCADA — because the actuator is I&C scope even when the valve body is an isolation valve.
+
+ Not intended for: General isolation and service piping valves selected for tight shutoff rather than throttling control — manual or automated gate, globe-stop, check, plug, ball, and butterfly valves used for on-off isolation — and the body, end-connection, and material standards that govern those valves (AWWA C500/C504/C507/C508/C515 and similar, MSS SP series, and API 600/602/608/609). Those are piping valves and belong to a future Mechanical / Plumbing piping-valve standard, not this one; this standard addresses an isolation valve only through its electric actuator when that actuator is the SCADA-controlled final element. Also excludes: pressure-relief, safety, and pressure/vacuum vent valves; self-contained (non-powered) pressure- and temperature-regulating valves; pinch and diaphragm dosing valves for chemical metering; the controller that computes the loop output ([[sync/programmable-logic-controllers]]); the SCADA/HMI that supervises it ([[sync/scada-and-hmi-systems]]); the measuring instruments that close the loop ([[sync/process-instrumentation]], [[sync/flow-measurement]], [[sync/analytical-instrumentation]]); the control panel that houses the I/O ([[sync/industrial-control-panels]]); the field network that carries the signals ([[sync/process-control-networks]]); the instrument and signal wiring itself ([[sync/conductors-and-cables]]); and loop checkout, stroke testing, and tuning, which are performed under [[sync/control-systems-integration]].
+---
+
+# Scope {toc}
+
+## This specification covers the automated final control element of a process control loop: the modulating control valve, the actuator that positions it, the positioner that commands the actuator, and the accessories that complete the assembly, for industrial, process, and water and wastewater treatment facilities. {note}
+
+## Equipment covered includes the control-valve body and trim, the actuator (pneumatic spring-diaphragm, pneumatic piston, or electric), the valve positioner (analog, HART, or digital/fieldbus), and the mounted accessories — I/P transducer, air set and filter regulator, solenoid valve, limit switches, position transmitter, and volume booster — furnished and calibrated as a coordinated valve assembly. {note}
+
+## The final control element is the muscle of the control loop: the controller computes a demand, but the valve assembly is what actually changes the process, and a loop is only as good as the valve that executes it. {note}
+
+## The boundary of work under this standard is the assembled control valve from its inlet and outlet pipe connections, through the actuator and positioner, to the instrument-air supply connection and the field signal terminations. {note}
+
+## This standard also covers electric (motorized) actuators applied to isolation valves — motor-operated valves (MOVs) — where the actuator is the controls interface that opens, closes, or modulates the valve and reports position to the supervisory system, because the actuator and its controls are I&C scope even when the valve body is an isolation valve. {note}
+
+## This standard does not cover general isolation and service piping valves selected for shutoff rather than throttling, nor the body and material standards that govern them; those are piping valves governed by AWWA, MSS, and API standards and belong to a Mechanical/Plumbing piping-valve standard. {note}
+
+## The distinction between a throttling control valve and an isolation valve determines which standard applies: a valve selected to modulate flow against a process variable is in scope; a valve selected to fully open or fully close for isolation is out of scope except through its electric actuator. {note}
+
+## Control valve sizing shall comply with ANSI/ISA-75.01.01 (IEC 60534-2-1 Mod).
+
+## Seat leakage classification shall comply with ANSI/FCI 70-2.
+
+## The Contractor shall coordinate the control-valve loop demand signal with [[sync/programmable-logic-controllers]], the supervisory monitoring and position feedback with [[sync/scada-and-hmi-systems]], the instrument signal wiring with [[sync/conductors-and-cables]], and loop checkout and stroke testing with [[sync/control-systems-integration]].
+
+# Referenced Standards {toc}
+
+## Equipment, materials, and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited. {note}
+
+## Where conflicts exist between referenced standards, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
+
+| Standard | Title |
+|----------|-------|
+| ANSI/ISA-75.01.01 (IEC 60534-2-1 Mod) | Industrial-Process Control Valves — Flow Equations for Sizing Control Valves |
+| IEC 60534-2-1 | Industrial-Process Control Valves — Sizing Equations for Fluid Flow Under Installed Conditions |
+| IEC 60534-2-3 | Industrial-Process Control Valves — Flow Capacity — Test Procedures |
+| ANSI/ISA-75.08.01 | Face-to-Face Dimensions for Integral Flanged Globe-Style Control Valve Bodies (Classes 125, 150, 250, 300, 600) |
+| ANSI/ISA-75.08.02 | Face-to-Face Dimensions for Flanged and Flangeless Rotary Control Valves |
+| ANSI/FCI 70-2 | Control Valve Seat Leakage |
+| ISA-RP75.23 | Considerations for Evaluating Control Valve Cavitation |
+| IEC 60534-8-3 | Control Valves — Noise Considerations — Aerodynamic Noise Prediction Method |
+| IEC 60534-8-4 | Control Valves — Noise Considerations — Prediction of Noise Generated by Hydrodynamic Flow |
+| ANSI/ISA-75.19.01 | Hydrostatic Testing of Control Valves |
+| ANSI/ISA-75.13.01 | Method of Evaluating the Performance of Positioners with Analog Input Signals and Pneumatic Output |
+| ASME B16.34 | Valves — Flanged, Threaded, and Welding End (pressure-temperature ratings — factual body reference) |
+| ASME B16.5 | Pipe Flanges and Flanged Fittings (end-connection reference) |
+| AWWA C540 / C541 / C542 | Power-Actuating Devices / Cylinder and Vane Actuators / Electric Motor Actuators for Valves and Slide Gates (water/wastewater MOVs) |
+| ISO 15848-1 / -2 | Industrial Valves — Measurement, Test and Qualification Procedures for Fugitive Emissions |
+| NACE MR0175 / ISO 15156 | Materials for Use in H2S-Containing Environments in Oil and Gas Production (sour service) |
+| NAMUR NE 107 | Self-Monitoring and Diagnosis of Field Devices (status signal) |
+| IEC 61508 / IEC 61511 | Functional Safety of Safety Instrumented Systems (where the valve is a safety final element) |
+| IEC 60529 | Degrees of Protection Provided by Enclosures (IP Code) |
+| NEMA 250 | Enclosures for Electrical Equipment (1000 V Maximum) |
+| NEMA ICS 2 | Industrial Control and Systems: Controllers, Contactors, and Overload Relays (electric actuator controls) |
+| NFPA 70 | National Electrical Code (NEC) — area classification and wiring methods |
+
+# Submittals {toc}
+
+## Action Submittals {toc}
+
+### The Contractor shall submit the following for the Engineer's review and approval prior to procurement:
+
+- Control valve sizing calculation per ANSI/ISA-75.01.01 / IEC 60534-2-1 for each valve, showing the process data set (flow rate, inlet and outlet pressure, temperature, fluid properties, and specific gravity or molecular weight) at minimum, normal, and maximum flow cases, with the required and selected Cv, the percent of rated Cv at each case, and the resulting valve travel
+- Cavitation and flashing evaluation per ISA-RP75.23 for liquid service, identifying the service sigma versus the manufacturer's sigma limits, and the predicted aerodynamic or hydrodynamic noise per IEC 60534-8-3 or IEC 60534-8-4
+- Inherent flow characteristic (linear, equal-percentage, or quick-open) and rangeability for each valve, with justification for the characteristic against the installed pressure-drop ratio
+- Valve body and trim data: body style, size, end connection, pressure class and pressure-temperature rating, body and trim materials, packing type, and bonnet type (standard, extended, or bellows)
+- Seat leakage class per ANSI/FCI 70-2 for each valve
+- Actuator data: type (spring-diaphragm, piston, or electric), available thrust or torque versus the required seating and dynamic thrust or torque, bench-set range (pneumatic), fail-safe action, and stroking speed
+- Positioner data: signal input, communication protocol (analog 4-20 mA, HART, FOUNDATION Fieldbus, PROFIBUS PA), diagnostic capability, and NAMUR NE 107 status support
+- Accessory schedule: I/P transducer, air set/filter regulator, solenoid valve, limit switches, position transmitter, and volume booster, with the function of each
+- Electric actuator data (where applicable): motor rating, duty class (on-off, modulating S4, or continuous), torque switches and limit switches, network interface, local controls, and enclosure rating per NEMA 250 / IEC 60529
+- Area classification compliance documentation where the valve assembly is installed in a classified location per NFPA 70
+- Instrument-air consumption (steady-state and transient) for pneumatic assemblies, for coordination with the instrument-air system
+- Dimensioned assembly drawings showing face-to-face dimension per ANSI/ISA-75.08, weight, and required service clearances
+
+```datasheet
+label: Action Submittals Required
+type: checkbox
+options:
+ - "Sizing calculation per ISA-75.01.01 / IEC 60534-2-1"
+ - "Cavitation/flashing and noise evaluation"
+ - "Flow characteristic and rangeability with justification"
+ - "Body and trim data (materials, class, packing)"
+ - "Seat leakage class per ANSI/FCI 70-2"
+ - "Actuator data with thrust/torque margin and fail action"
+ - "Positioner data and protocol"
+ - "Accessory schedule"
+ - "Electric actuator data and enclosure rating (MOVs)"
+ - "Area classification compliance"
+ - "Instrument-air consumption"
+ - "Dimensioned assembly drawings"
+default: "Sizing calculation per ISA-75.01.01 / IEC 60534-2-1"
+```
+
+### Fabrication and shipment shall not proceed until action submittals have been reviewed and returned.
+
+## Closeout Submittals {toc}
+
+### At substantial completion, the Contractor shall provide the following before the control valves are accepted:
+
+- Operation and maintenance manuals for each valve assembly, including disassembly, trim replacement, packing adjustment, and calibration procedures
+- Factory hydrostatic shell test certificate per ANSI/ISA-75.19.01 and seat leakage test record per ANSI/FCI 70-2 for each valve
+- As-calibrated positioner records, including the configured characteristic, span, zero, and the as-left signature (valve signature and step/ramp response) for digital positioners
+- Loop checkout and stroke test records (full stroke and, where applicable, partial stroke) coordinated with [[sync/control-systems-integration]]
+- Bench-set verification record (pneumatic) or torque-switch and limit-switch setting record (electric)
+- Diagnostic baseline captured by digital positioners or electric actuators at commissioning, for future comparison
+- Fugitive-emission packing certification per ISO 15848 where specified
+- Warranty documentation
+- Spare parts inventory list with manufacturer part numbers
+
+```datasheet
+label: Closeout Submittals Required
+type: checkbox
+options:
+ - "Operation and maintenance manuals"
+ - "Factory hydrostatic and seat-leakage test records"
+ - "As-calibrated positioner records and signatures"
+ - "Loop checkout and stroke test records"
+ - "Bench-set or torque/limit-switch setting record"
+ - "Commissioning diagnostic baseline"
+ - "Fugitive-emission packing certification (where specified)"
+ - "Warranty documentation"
+ - "Spare parts inventory list with part numbers"
+default: "Operation and maintenance manuals"
+```
+
+# Quality Assurance {toc}
+
+## Manufacturer Qualifications {toc}
+
+### Control valves and actuators shall be the products of a manufacturer with a minimum of ten years of continuous experience designing and producing modulating control valves of the type specified.
+
+### The manufacturer shall maintain an ISO 9001 certified quality management system.
+
+### Replacement trim, packing, and actuator parts shall be available for a minimum of fifteen years from the date of manufacture.
+
+## Sizing Responsibility {toc}
+
+### The valve manufacturer shall perform and stamp the final sizing calculation for each valve using the process data set provided by the Engineer.
+
+### The manufacturer shall not substitute a different valve size or trim from that calculated without the Engineer's written approval.
+
+### A control valve sized only on the line size — rather than on the process data set and the required Cv — is the single most common control-valve error, producing a valve that operates near the seat at normal flow with poor controllability and accelerated trim wear. {note}
+
+## Single-Source Responsibility {toc}
+
+### For each control valve, the body, trim, actuator, positioner, and accessories shall be furnished, assembled, and calibrated by or through a single supplier as a coordinated assembly.
+
+### Field-assembling a valve body from one supplier with an actuator and positioner from others transfers the responsibility for thrust margin, bench set, and characterization to the field, where it is frequently done incorrectly. {note}
+
+## Listing and Area Classification {toc}
+
+### Electrical components of the valve assembly — positioner, solenoid, limit switches, position transmitter, and electric actuator — shall be listed by a Nationally Recognized Testing Laboratory for the area classification of their installed location per NFPA 70.
+
+### In classified (hazardous) locations, the protection method (explosionproof, intrinsically safe, or increased safety) shall be as required for the area class, division or zone, and gas group.
+
+# Environmental and Service Conditions {toc}
+
+## Installation Environment {toc}
+
+```datasheet
+label: Valve Installation Environment
+type: select
+options:
+ - "Indoor — heated process building or control building"
+ - "Indoor — unheated process area"
+ - "Outdoor — exposed (rain, sun, wind-driven dust)"
+ - "Below-grade vault or wet well (WTP/WWTP)"
+ - "Submerged or intermittently flooded"
+default: "Outdoor — exposed (rain, sun, wind-driven dust)"
+```
+
+### Valve assemblies shall be selected and rated for the conditions at the installation site, including ambient temperature extremes, humidity, precipitation, and airborne contaminants.
+
+### Outdoor and below-grade assemblies shall protect the positioner, solenoid, and electrical accessories against water ingress to the rating specified for the location.
+
+## Enclosure Protection Rating {toc}
+
+```datasheet
+label: Electrical Accessory Enclosure Rating
+type: select
+options:
+ - "NEMA 4 / IP66 — outdoor, hose-directed water (standard for WTP/WWTP outdoor)"
+ - "NEMA 4X / IP66 — corrosive or coastal outdoor"
+ - "NEMA 6 / IP67 — occasional submersion (vaults, wet wells)"
+ - "NEMA 6P / IP68 — prolonged submersion"
+ - "NEMA 7 / explosionproof — Class I Division 1 hazardous"
+ - "NEMA 12 / IP54 — indoor industrial, dust and dripping"
+default: "NEMA 4 / IP66 — outdoor, hose-directed water (standard for WTP/WWTP outdoor)"
+```
+
+### Positioners, solenoids, limit switches, position transmitters, and electric actuator housings shall meet the enclosure rating specified for the installation environment per NEMA 250 and IEC 60529.
+
+### Water and wastewater service routinely exposes valve electrics to washdown, condensation, and flooding; an underrated enclosure admits moisture that corrodes the positioner and fails the loop. {note}
+
+## Ambient Temperature {toc}
+
+```datasheet
+label: Ambient Temperature Range
+type: text
+unit: "°F"
+drawing_ref: true
+default: "-20°F to 120°F (verify project location and indoor/outdoor)"
+```
+
+### The valve assembly, including the positioner, solenoid, and actuator diaphragm or seals, shall be rated for the project ambient temperature range without loss of function.
+
+### In cold climates, freeze protection of instrument air (dryness/dewpoint), valve cavities holding stagnant liquid, and below-grade assemblies shall be coordinated with the project mechanical design.
+
+# Application and Loop Role {toc}
+
+## Final Control Element Function {toc}
+
+### The control valve shall be selected to modulate the controlled process variable (flow, pressure, level, or temperature) in response to the loop demand signal from the controller. {note}
+
+### The valve assembly shall accept the controller output and position the valve so that the installed flow tracks the demand across the required operating range. {note}
+
+### The controller output signal type and range shall be coordinated with [[sync/programmable-logic-controllers]] and the position feedback with [[sync/scada-and-hmi-systems]].
+
+## Controlled Variable {toc}
+
+```datasheet
+label: Controlled Process Variable
+type: select
+options:
+ - "Flow"
+ - "Pressure"
+ - "Level"
+ - "Temperature"
+ - "pH or analytical setpoint"
+ - "Differential pressure"
+default: "Flow"
+```
+
+### The controlled variable, the loop operating cases (minimum, normal, maximum), and the required turndown shall be [[drawing: as indicated on the process and instrumentation diagrams (P&IDs) and the instrument index]].
+
+## Service Type {toc}
+
+### The service fluid and its phase determine the sizing equations, the trim selection, and the material requirements. {note}
+
+```datasheet
+label: Service Fluid Type
+type: select
+options:
+ - "Clean liquid (water, treated water, clear process liquid)"
+ - "Dirty or solids-bearing liquid (raw water, sludge, slurry)"
+ - "Gas or vapor"
+ - "Steam"
+ - "Two-phase or flashing liquid"
+ - "Corrosive chemical (acid, caustic, oxidant)"
+default: "Clean liquid (water, treated water, clear process liquid)"
+```
+
+### The service fluid, composition, and any solids or abrasive content shall be [[drawing: as indicated on the P&IDs and process datasheets]].
+
+# Valve Body Style {toc}
+
+## Body Style Selection {toc}
+
+### The body style shall match the service, the required rangeability, the available pressure drop, and the cleanliness of the fluid. {note}
+### Globe (sliding-stem) valves provide precise throttling, high rangeability, and ready accommodation of anti-cavitation and low-noise trim, and are the default for clean modulating service where tight control matters. {note}
+### Segmented-ball valves provide high capacity and high rangeability with good shutoff, tolerate fiber and solids, and are common in pulp, sludge, and high-turndown liquid service. {note}
+### Eccentric rotary-plug valves combine rotary economy with globe-like control and good shutoff, and resist coating and scaling. {note}
+### High-performance (eccentric-disc) butterfly valves provide high capacity in large line sizes at low cost and are used for modulating control where the pressure drop is modest, including large water and wastewater flow control. {note}
+
+```datasheet
+label: Control Valve Body Style
+type: radio
+options:
+ - "Globe — sliding stem, single or balanced cage trim"
+ - "Segmented ball (V-notch) — high capacity, high rangeability"
+ - "Eccentric rotary plug — globe-like control, anti-coating"
+ - "High-performance butterfly (eccentric disc) — large line, modulating"
+default: "Globe — sliding stem, single or balanced cage trim"
+```
+
+### The body style shall not be a quarter-turn isolation valve repurposed for throttling unless it is specifically the high-performance modulating type with a control-quality actuator and positioner.
+
+## Body Size and End Connection {toc}
+
+```datasheet
+label: Valve Body Size
+type: range
+unit: in. (NPS)
+drawing_ref: true
+options:
+ min: 0.5
+ max: 48
+ setpoints: [0.5, 0.75, 1, 1.5, 2, 3, 4, 6, 8, 10, 12, 16, 20, 24, 30, 36, 48]
+default: 4
+```
+
+```datasheet
+label: End Connection
+type: select
+options:
+ - "Flanged — ASME B16.5 raised face"
+ - "Flanged — flat face (cast iron / lined systems)"
+ - "Flangeless (wafer) — between-flange rotary"
+ - "Lug — between-flange, tapped"
+ - "Butt-weld"
+ - "Threaded (NPT) — small valves only"
+ - "Grooved (WTP/WWTP yard piping)"
+default: "Flanged — ASME B16.5 raised face"
+```
+
+### The body size shall be the size determined by the sizing calculation, which is frequently smaller than the line size; the valve shall be installed with reducers as required.
+
+### The valve body size shall not be selected to match the line size by default.
+
+### Selecting the valve to match the line size oversizes most control valves, forcing them to operate near the seat where control is poor and trim wears rapidly. {note}
+
+## Pressure Class {toc}
+
+```datasheet
+label: Body Pressure Class
+type: select
+options:
+ - "ASME Class 150"
+ - "ASME Class 300"
+ - "ASME Class 600"
+ - "ASME Class 900"
+ - "ASME Class 1500"
+ - "ASME Class 2500"
+ - "AWWA / cast-iron rating (WTP/WWTP low-pressure)"
+default: "ASME Class 150"
+```
+
+### The body pressure-temperature rating shall equal or exceed the maximum service conditions per ASME B16.34, and the body and end connections shall match the connected piping class.
+
+# Sizing and Flow Coefficient {toc}
+
+## Required Flow Coefficient {toc}
+
+### The required flow coefficient (Cv) shall be calculated per ANSI/ISA-75.01.01 / IEC 60534-2-1 for the minimum, normal, and maximum flow cases using the process data set. {note}
+
+### The valve shall be sized so that at the maximum flow case the required Cv does not exceed approximately 80% of the valve's rated Cv, and at the minimum flow case the valve travel is not so low that control becomes unstable.
+
+### The selected valve travel shall fall within the controllable range of the trim — typically between about 20% and 80% of rated travel across the normal operating cases.
+
+### Sizing shall account for piping geometry factors (reducers and expanders) and, for compressible flow, for the gas expansion factor and the pressure-drop ratio.
+
+```datasheet
+label: Sizing Basis Documentation
+type: checkbox
+options:
+ - "Minimum, normal, and maximum flow cases provided"
+ - "Inlet and outlet pressure at each case"
+ - "Temperature and fluid properties at each case"
+ - "Piping geometry factor (reducers/expanders) applied"
+ - "Required Cv and percent of rated Cv at each case"
+ - "Resulting valve travel at each case"
+default: "Minimum, normal, and maximum flow cases provided"
+```
+
+## Process Data Set {toc}
+
+```datasheet
+label: Maximum Flow Rate
+type: text
+drawing_ref: true
+default: "As indicated on the P&IDs and instrument datasheets (with units)"
+```
+
+```datasheet
+label: Inlet Pressure (P1)
+type: text
+unit: psig
+drawing_ref: true
+default: "As indicated on the process datasheets"
+```
+
+```datasheet
+label: Pressure Drop at Maximum Flow (P1 - P2)
+type: text
+unit: psi
+drawing_ref: true
+default: "As indicated on the process datasheets"
+```
+
+### The process data set — flow, inlet pressure, pressure drop, temperature, and fluid properties at each flow case — is [[drawing: as indicated on the P&IDs and process datasheets]] and shall be provided to the valve manufacturer for sizing.
+
+### The pressure drop across the valve shall be the actual drop at each flow case, not an assumed fixed value; using an arbitrary fixed drop produces a mis-sized valve when the system curve is pump- or elevation-dominated. {note}
+
+# Flow Characteristic and Rangeability {toc}
+
+## Inherent Flow Characteristic {toc}
+
+### The inherent flow characteristic relates flow capacity to valve travel at constant pressure drop, and shall be selected so that the installed characteristic — the relationship of flow to travel under the actual, varying system pressure drop — is approximately linear. {note}
+### Equal-percentage trim produces equal proportional changes in Cv for equal increments of travel and is the most common selection, because it compensates for the falling valve pressure drop as flow rises in systems where the valve takes a small share of the total system drop. {note}
+### Linear trim produces flow proportional to travel and is appropriate where the valve pressure drop is a large and relatively constant share of the system drop. {note}
+### Quick-open trim produces large flow change for small initial travel and is not used for modulating control; it suits on-off and some self-acting service only. {note}
+
+```datasheet
+label: Inherent Flow Characteristic
+type: radio
+options:
+ - "Equal-percentage (most modulating service)"
+ - "Linear (valve drop a large, constant share of system drop)"
+ - "Quick-open (on-off only — not for modulating control)"
+ - "Modified parabolic (intermediate, manufacturer-specific)"
+default: "Equal-percentage (most modulating service)"
+```
+
+### The characteristic shall be selected against the pressure-drop ratio (valve drop divided by system drop) at maximum flow: equal-percentage where that ratio is low, linear where it approaches unity.
+
+### Specifying linear trim on a system where the valve takes only a small share of the pressure drop yields an installed characteristic that behaves like quick-open — most of the control occurs in the first portion of travel, and the loop is difficult to tune. {note}
+
+## Rangeability {toc}
+
+### Rangeability is the ratio of the maximum to the minimum controllable flow coefficient over which the valve holds its characteristic. {note}
+### Higher rangeability lets one valve control a wider flow range without losing characterization at low travel. {note}
+
+```datasheet
+label: Required Rangeability
+type: select
+options:
+ - "30:1 (globe, standard)"
+ - "50:1 (globe, high-performance trim)"
+ - "100:1 or greater (segmented ball, special trim)"
+ - "20:1 (rotary, standard)"
+default: "30:1 (globe, standard)"
+```
+
+### The valve rangeability shall equal or exceed the turndown required by the process operating cases.
+
+# Cavitation, Flashing, and Noise {toc}
+
+## Cavitation and Flashing Evaluation {toc}
+
+### Liquid service shall be evaluated for cavitation and flashing per ISA-RP75.23 using the sigma (σ) method, comparing the service sigma to the manufacturer's sigma limits for the selected valve and trim. {note}
+### Cavitation occurs when the local pressure at the vena contracta falls below the fluid vapor pressure and then recovers, collapsing vapor bubbles against trim and body surfaces and causing severe erosion, noise, and vibration. {note}
+### Flashing occurs when the outlet pressure remains below vapor pressure so the fluid stays partly vaporized downstream, eroding the body by high-velocity two-phase flow. {note}
+
+```datasheet
+label: Cavitation / Flashing Condition
+type: select
+options:
+ - "None expected — service sigma well above incipient"
+ - "Incipient cavitation — monitor, standard trim acceptable"
+ - "Cavitation expected — anti-cavitation (multi-stage) trim required"
+ - "Flashing service — hardened body and erosion-resistant trim required"
+default: "None expected — service sigma well above incipient"
+```
+
+### Where the evaluation predicts damaging cavitation, anti-cavitation trim that stages the pressure drop (multi-stage, multi-path, or tortuous-path) shall be provided to keep each stage above the cavitation threshold.
+
+### Where the service flashes, the valve body and trim shall be selected for the resulting two-phase erosion, with a hardened or hardfaced trim and an erosion-resistant body, and the body style shall direct the expanding flow away from the body wall.
+
+### Cavitation cannot be eliminated by trim material alone; if the pressure profile is not staged, even hardened trim erodes — the pressure drop must be managed, not merely resisted. {note}
+
+## Predicted Noise {toc}
+
+### Predicted valve noise shall be calculated per IEC 60534-8-3 for compressible (aerodynamic) flow and IEC 60534-8-4 for liquid (hydrodynamic) flow. {note}
+
+```datasheet
+label: Maximum Predicted Sound Pressure Level
+type: range
+unit: dBA
+options:
+ min: 75
+ max: 110
+ setpoints: [80, 85, 90, 95, 100, 105, 110]
+default: 85
+```
+
+### Predicted sound pressure level at 1 m from the valve shall not exceed the limit specified for the area.
+
+### Where predicted noise exceeds the limit, low-noise trim, downstream diffusers or resistance plates, heavier-wall downstream pipe, or path attenuation shall be provided.
+
+### Aerodynamic valve noise above approximately 100 dBA also indicates high trim velocity that mechanically damages the trim; noise control and trim longevity are linked. {note}
+
+# Trim, Materials, and Seat Leakage {toc}
+
+## Trim Materials {toc}
+
+### Trim materials shall be selected for the service: erosion, corrosion, temperature, and any abrasive solids. {note}
+
+```datasheet
+label: Trim Material
+type: select
+options:
+ - "Type 316 stainless steel (standard clean service)"
+ - "316 SST with hardened (hardfaced) seat and plug (cavitation/erosion)"
+ - "Stellite or tungsten-carbide trim (severe erosion/cavitation)"
+ - "Alloy 20, Hastelloy, or titanium (aggressive chemical service)"
+ - "NACE MR0175-compliant trim (sour / H2S service)"
+default: "Type 316 stainless steel (standard clean service)"
+```
+
+### Trim for cavitating, flashing, or solids-bearing service shall be hardened or hardfaced.
+
+### Trim for sour (H2S-containing) service shall comply with NACE MR0175 / ISO 15156.
+
+## Body Material {toc}
+
+```datasheet
+label: Body Material
+type: select
+options:
+ - "Carbon steel (WCB) — general clean service"
+ - "Cast iron / ductile iron — WTP/WWTP low-pressure water service"
+ - "Stainless steel (CF8M / 316) — corrosive or clean process"
+ - "Alloy (Alloy 20, Hastelloy, titanium) — aggressive chemical"
+ - "Lined (PTFE, PFA, rubber) — corrosive or abrasive"
+default: "Carbon steel (WCB) — general clean service"
+```
+
+### The body material shall match the service fluid, the pressure-temperature rating, and the connected piping material.
+
+## Packing {toc}
+
+```datasheet
+label: Stem Packing
+type: select
+options:
+ - "PTFE V-ring (standard, low friction)"
+ - "Graphite (high temperature)"
+ - "Live-loaded (spring-energized, low maintenance)"
+ - "Low-emission / fugitive-emission certified (ISO 15848)"
+default: "PTFE V-ring (standard, low friction)"
+```
+
+### Stem packing shall be selected for the service temperature and the emission requirement.
+
+### Where fugitive-emission control is required, the packing shall be certified to ISO 15848 to the specified emission class.
+
+### Packing friction directly degrades positioning resolution; over-tightened or high-friction packing causes deadband and limit-cycling in the loop, so packing selection is a control-performance decision, not only a sealing decision. {note}
+
+## Seat Leakage Class {toc}
+
+### The seat leakage class per ANSI/FCI 70-2 shall be specified for each valve according to how tightly the valve must shut off when fully closed. {note}
+### Class IV (metal seat) is the standard for most metal-seated modulating valves; Class V is for critical metal-seat shutoff under high differential; Class VI (bubble-tight, soft seat) is for applications requiring near-zero leakage. {note}
+
+```datasheet
+label: Seat Leakage Class (ANSI/FCI 70-2)
+type: radio
+options:
+ - "Class IV — metal seat, standard modulating shutoff"
+ - "Class V — metal seat, tight shutoff under high differential"
+ - "Class VI — soft seat, bubble-tight"
+ - "Class II or III — general (where tight shutoff not required)"
+default: "Class IV — metal seat, standard modulating shutoff"
+```
+
+### A modulating control valve shall not be relied upon as the process isolation point; where positive isolation is required, a dedicated isolation valve (outside this standard) shall be provided in series.
+
+### Specifying Class VI bubble-tight shutoff on a valve whose only duty is throttling adds soft-seat cost and limits temperature and erosion tolerance for a shutoff that the loop never requires. {note}
+
+# Actuators {toc}
+
+## Actuator Type {toc}
+
+### The actuator shall be sized and selected to position the valve against the maximum dynamic and seating forces at the available supply pressure or motor rating, with margin. {note}
+### Pneumatic spring-diaphragm actuators provide inherent fail-safe action from the spring, smooth modulation, and are the default for modulating service where instrument air is available. {note}
+### Pneumatic piston actuators provide higher thrust and faster stroking for large valves and high differential pressure, and are double-acting (requiring a separate fail-safe means) or spring-return. {note}
+### Electric actuators are used where instrument air is unavailable or undesirable, and are required for most water/wastewater MOVs and for remote sites. {note}
+
+```datasheet
+label: Actuator Type
+type: radio
+options:
+ - "Pneumatic spring-diaphragm (modulating, fail-safe spring)"
+ - "Pneumatic piston — spring-return (high thrust, fail-safe)"
+ - "Pneumatic piston — double-acting (with fail-safe accumulator/SOV)"
+ - "Electric — modulating duty (S4 / continuous rated)"
+ - "Electric — on/off or open/close (MOV isolation)"
+default: "Pneumatic spring-diaphragm (modulating, fail-safe spring)"
+```
+
+## Actuator Sizing {toc}
+
+### The actuator output (thrust for sliding-stem, torque for rotary) shall equal or exceed the maximum required seating and dynamic force, including the unbalance force at maximum differential pressure, the packing friction, and the seat load, with a minimum 25% margin at the minimum available air supply pressure. {note}
+
+```datasheet
+label: Actuator Sizing Margin
+type: select
+options:
+ - "25% minimum margin at minimum supply pressure (standard)"
+ - "50% margin (high differential or critical service)"
+ - "Per manufacturer maximum-shutoff dP rating"
+default: "25% minimum margin at minimum supply pressure (standard)"
+```
+
+### Actuator output shall be verified against the valve's published maximum shutoff differential pressure rating; an undersized actuator cannot close against the process and stalls. {note}
+
+### The minimum guaranteed instrument-air supply pressure shall be used as the sizing basis, not the nominal header pressure.
+
+## Bench Set (Pneumatic) {toc}
+
+### The pneumatic actuator bench set shall be specified to preload the spring so the actuator overcomes the seat load and unbalance force and delivers full travel within the diaphragm pressure range. {note}
+
+```datasheet
+label: Instrument Signal / Diaphragm Range
+type: select
+options:
+ - "3-15 psig (standard diaphragm range)"
+ - "6-30 psig (high-seat-load applications)"
+ - "Per positioner output (positioner-driven, bench set selected for thrust)"
+default: "Per positioner output (positioner-driven, bench set selected for thrust)"
+```
+
+### Where a positioner is provided, the bench set shall be selected for thrust and seating rather than for direct signal-range correspondence, and the positioner shall characterize the signal-to-travel relationship.
+
+## Fail-Safe Action {toc}
+
+### The fail-safe action on loss of signal, loss of air, or loss of power shall be specified for each valve based on the process safe state. {note}
+
+```datasheet
+label: Fail-Safe Action
+type: radio
+options:
+ - "Fail closed (FC) — spring closes valve on loss of air/power"
+ - "Fail open (FO) — spring opens valve on loss of air/power"
+ - "Fail last (FL) — valve holds last position (requires lock-up or motor brake)"
+default: "Fail closed (FC) — spring closes valve on loss of air/power"
+```
+
+### The fail-safe action is [[drawing: as indicated on the P&IDs]] and shall place the process in its defined safe state.
+
+### Fail-last action shall be provided only with a positive holding means — a pneumatic lock-up relay with an air reservoir for pneumatic actuators, or a self-locking gear train or brake for electric actuators — because a plain double-acting or electric actuator does not hold position when its motive power is lost.
+
+### Choosing the wrong fail action is a safety error, not a preference: a feedwater or coolant valve that fails closed when it should fail open can damage equipment or endanger personnel. {note}
+
+## Stroking Speed {toc}
+
+```datasheet
+label: Stroking Speed Requirement
+type: select
+options:
+ - "Standard modulating speed (no special requirement)"
+ - "Fast stroke — volume booster or piston actuator (surge/anti-water-hammer)"
+ - "Slow stroke — controlled closure to prevent water hammer (WTP/WWTP)"
+default: "Standard modulating speed (no special requirement)"
+```
+
+### Where rapid closure would induce water hammer in a liquid line, the closure speed shall be limited; where rapid action is required for surge or trip duty, a volume booster or piston actuator shall be provided.
+
+# Electric Actuators on Isolation Valves (MOVs) {toc}
+
+## Scope of Electric Actuation {toc}
+
+### Electric actuators applied to isolation valves (MOVs) are in this standard because the actuator and its controls are the I&C interface that opens, closes, or modulates the valve and reports its position to the supervisory system, even though the valve body is an isolation valve governed elsewhere. {note}
+
+### The valve body, end connections, and body materials of an MOV isolation valve are governed by the applicable piping-valve standard (AWWA, MSS, or API) and are outside this standard; this standard governs only the electric actuator and its controls. {note}
+
+### Electric actuators for water and wastewater valves and slide gates shall comply with AWWA C542.
+
+## Duty Rating {toc}
+
+```datasheet
+label: Electric Actuator Duty
+type: radio
+options:
+ - "On/off (open-close) — Class A/B duty"
+ - "Inching/positioning — Class C duty"
+ - "Modulating — Class D (S4) continuous-rated for high starts/hour"
+default: "On/off (open-close) — Class A/B duty"
+```
+
+### The electric actuator duty rating shall match the operating frequency: open/close isolation duty for valves that operate occasionally, and a modulating-rated (S4, continuous) actuator with a high permissible starts-per-hour rating for valves that throttle continuously.
+
+### Applying an open/close-rated actuator to a continuously modulating duty overheats the motor and fails it prematurely; modulating duty requires an actuator specifically rated for the start frequency. {note}
+
+## Position Feedback and Controls {toc}
+
+### The electric actuator shall provide position feedback (open, closed, and intermediate position) to the supervisory system per [[sync/scada-and-hmi-systems]]. {note}
+
+```datasheet
+label: Electric Actuator Interface
+type: select
+options:
+ - "Discrete — open/close command and open/closed status (hardwired)"
+ - "Analog — 4-20 mA command and 4-20 mA position feedback"
+ - "Network — Modbus RTU/TCP"
+ - "Network — PROFIBUS DP / PROFINET"
+ - "Network — EtherNet/IP"
+ - "Network — FOUNDATION Fieldbus"
+default: "Discrete — open/close command and open/closed status (hardwired)"
+```
+
+### The actuator shall include torque switches to protect the valve and actuator against overtorque at the seat and against jamming, and limit switches to define the open and closed positions.
+
+### The actuator shall provide local open/close/stop controls and a local/remote selector, with the local controls lockable where required.
+
+### The network protocol and the discrete or analog interface points shall be coordinated with the integrator under [[sync/control-systems-integration]] and the network design under [[sync/process-control-networks]].
+
+# Positioner and Accessories {toc}
+
+## Valve Positioner {toc}
+
+### Each modulating control valve shall be furnished with a valve positioner that compares the demand signal to the measured stem or shaft position and adjusts the actuator until the position matches the demand. {note}
+### A positioner overcomes packing friction, actuator hysteresis, and dynamic load to deliver accurate, repeatable positioning, and is required on essentially all modulating valves. {note}
+
+```datasheet
+label: Positioner Type
+type: radio
+options:
+ - "Analog (electro-pneumatic) — 4-20 mA input, no diagnostics"
+ - "Digital with HART — 4-20 mA input plus HART diagnostics (standard)"
+ - "Digital fieldbus — FOUNDATION Fieldbus or PROFIBUS PA"
+ - "Pneumatic positioner — 3-15 psig input (legacy/no electrical)"
+default: "Digital with HART — 4-20 mA input plus HART diagnostics (standard)"
+```
+
+### A positioner shall be provided on every modulating valve; relying on the bare actuator signal-to-pressure relationship without a positioner leaves the loop with the actuator's hysteresis and the packing friction uncorrected.
+
+## Positioner Diagnostics {toc}
+
+### Digital positioners shall capture and store diagnostic information for predictive maintenance, including valve signature, friction trend, travel histogram, cycle count, and response signatures. {note}
+### The positioner shall report device health using a NAMUR NE 107 status classification (failure, function check, out of specification, maintenance required) to the supervisory system. {note}
+
+```datasheet
+label: Positioner Diagnostics
+type: checkbox
+options:
+ - "Valve signature (capture at commissioning as baseline)"
+ - "Online friction and travel trending"
+ - "Travel histogram and cycle counter"
+ - "NAMUR NE 107 status reporting"
+ - "Partial stroke test (PST) — safety final elements"
+default: "Valve signature (capture at commissioning as baseline)"
+```
+
+### Where the valve is a final element of a safety instrumented function, the positioner shall support partial stroke testing (PST) to improve the diagnostic coverage of the function per IEC 61508 / IEC 61511, and the safety requirement shall be coordinated with the safety system design.
+
+## Mounted Accessories {toc}
+
+### The valve assembly accessories shall be selected for the duty and mounted and tubed at the factory as part of the assembly. {note}
+
+```datasheet
+label: Mounted Accessories
+type: checkbox
+options:
+ - "Air filter regulator (air set) — conditions instrument air"
+ - "I/P transducer (where positioner is pneumatic-input)"
+ - "Solenoid valve — drives valve to fail position on trip"
+ - "Volume booster — speeds large-actuator stroking"
+ - "Limit switches — discrete open/closed position to SCADA"
+ - "Position transmitter — independent 4-20 mA position feedback"
+ - "Handwheel / manual override"
+default: "Air filter regulator (air set) — conditions instrument air"
+```
+
+### An air filter regulator (air set) shall be provided on every pneumatic assembly to condition the instrument air to the positioner and actuator.
+
+### A solenoid valve shall be provided where the valve must be driven to its fail position on a trip independently of the modulating signal.
+
+### A volume booster shall be provided where a large actuator must stroke faster than the positioner output alone can fill or exhaust it.
+
+### A separate position transmitter shall be provided where the supervisory system requires position feedback independent of the positioner's internal feedback.
+
+## Instrument Air Supply {toc}
+
+```datasheet
+label: Instrument Air Supply Pressure
+type: range
+unit: psig
+drawing_ref: true
+options:
+ min: 20
+ max: 150
+ setpoints: [20, 30, 40, 60, 80, 100, 120, 150]
+default: 80
+```
+
+### The instrument-air supply pressure and quality (dryness/dewpoint and particulate per the instrument-air standard) shall be confirmed available at each pneumatic valve.
+
+### The actuator sizing shall be based on the minimum guaranteed supply pressure, and the assembly air consumption shall be reported for coordination with the instrument-air system.
+
+### Wet or dirty instrument air is the leading cause of positioner and solenoid failure in the field; air quality is a prerequisite for valve reliability, not an optional refinement. {note}
+
+# Factory Testing {toc}
+
+## Hydrostatic and Seat Leakage Tests {toc}
+
+### Each valve body shall be hydrostatically shell-tested by the manufacturer per ANSI/ISA-75.19.01 to prove the structural integrity and leak-tightness of the pressure-retaining parts. {note}
+
+### Each valve shall be seat-leakage tested to the specified ANSI/FCI 70-2 class.
+
+```datasheet
+label: Factory Test Documentation
+type: checkbox
+options:
+ - "Hydrostatic shell test per ISA-75.19.01"
+ - "Seat leakage test per ANSI/FCI 70-2 (specified class)"
+ - "Stroke/calibration record (signal vs. travel)"
+ - "Actuator bench-set or torque-switch verification"
+ - "Fugitive-emission packing test (ISO 15848, where specified)"
+default: "Hydrostatic shell test per ISA-75.19.01"
+```
+
+### Test certificates shall be furnished as closeout submittals.
+
+## Factory Calibration {toc}
+
+### The manufacturer shall stroke and calibrate each assembled valve, verifying that the valve moves through full travel in the correct direction in response to the demand signal and that the positioner reports position accurately.
+
+### For digital positioners, the as-shipped configuration (characteristic, span, zero) and a baseline valve signature shall be recorded.
+
+# Installation {toc}
+
+## Orientation and Access {toc}
+
+### Control valves shall be installed in the orientation recommended by the manufacturer, with the actuator accessible for calibration and maintenance and the flow direction matching the body arrow.
+
+### Sufficient clearance shall be maintained above and around the valve for actuator removal, trim service, and packing replacement [[drawing: per the equipment arrangement and piping drawings]].
+
+### Sliding-stem globe valves should be installed with the stem vertical and the actuator above the line wherever practical, so the actuator weight is supported and condensate does not collect in the actuator.
+
+## Piping and Isolation {toc}
+
+### Block-and-bypass valves and upstream and downstream isolation valves shall be provided around each control valve [[drawing: as indicated on the P&IDs]] so the control valve can be isolated and serviced without draining the system.
+
+### The required straight pipe runs upstream and downstream and any reducers shall be installed as shown on the drawings, and the valve shall be installed free of pipe strain.
+
+### Welding slag, scale, and construction debris shall be flushed from the line before the control valve is installed or, where the valve is installed first, a temporary spool shall be used during flushing to protect the trim.
+
+### Construction debris drawn through a new control valve cuts the seat and trim and is a frequent cause of early seat-leakage failure. {note}
+
+## Air and Signal Connections {toc}
+
+### Instrument-air tubing shall be run to each pneumatic valve from the conditioned instrument-air supply, sloped and trapped to drain condensate, and connected through the air set.
+
+### Signal and feedback wiring shall be installed and terminated per [[sync/conductors-and-cables]], with analog loops separated from power wiring and shields grounded at one end only.
+
+### Network-connected positioners and electric actuators shall be connected per [[sync/process-control-networks]].
+
+# Field Commissioning {toc}
+
+## Loop Checkout and Stroke Test {toc}
+
+### After installation, each valve shall be loop-checked and stroke-tested under [[sync/control-systems-integration]], verifying that the demand from the controller produces the correct travel and direction, that the position feedback to [[sync/scada-and-hmi-systems]] agrees with the actual position, and that the fail-safe action occurs on loss of signal, air, or power. {note}
+
+```datasheet
+label: Commissioning Tests
+type: checkbox
+options:
+ - "Full-stroke test (0-100-0%) with travel vs. signal verified"
+ - "Fail-safe action verified (loss of signal/air/power)"
+ - "Position feedback to SCADA verified against actual travel"
+ - "Calibration of zero and span confirmed as-left"
+ - "Packing adjusted to eliminate deadband without binding"
+ - "Partial stroke test configured (safety final elements)"
+ - "Diagnostic baseline captured (digital positioner/actuator)"
+default: "Full-stroke test (0-100-0%) with travel vs. signal verified"
+```
+
+### Deadband and resolution shall be checked and the packing adjusted so the valve responds to small signal changes without binding or limit-cycling.
+
+### The as-left calibration and the commissioning diagnostic baseline shall be recorded for each valve.
+
+## Coordination with the Loop {toc}
+
+### Loop tuning is performed under [[sync/control-systems-integration]] after the valve is commissioned; the valve assembly shall be left in a condition (correct characterization, minimal deadband, verified travel) that allows the loop to be tuned. {note}
+
+### A valve with excessive packing friction, incorrect characterization, or an undersized actuator cannot be tuned out at the controller and shall be corrected at the valve. {note}
+
+# Delivery, Storage, and Handling {toc}
+
+## Control valves shall be delivered with end-connection protectors in place and with the actuator, positioner, and accessories factory-mounted and protected.
+
+## Valves shall be stored indoors, clean and dry, with electrical and pneumatic ports capped until connection.
+
+## Valves shall be handled and rigged by the body or by manufacturer-designated lifting points, never by the actuator, positioner, tubing, or accessories.
+
+## Lifting or supporting a valve by its actuator or positioner bends linkages and damages the position feedback, throwing off the calibration before the valve is ever installed. {note}
+
+# Warranty {toc}
+
+## Warranty Terms {toc}
+
+```datasheet
+label: Warranty Period
+type: select
+options:
+ - "1 year from substantial completion (standard)"
+ - "2 years from substantial completion"
+ - "18 months from shipment or 12 months from startup, whichever first"
+default: "1 year from substantial completion (standard)"
+```
+
+### The manufacturer shall warrant each control valve assembly against defects in materials and workmanship for the period selected from the date of substantial completion.
+
+### The warranty shall cover the body, trim, actuator, positioner, and factory-mounted accessories as a coordinated assembly.
+
+# Spare Parts {toc}
+
+## Spare Parts Package {toc}
+
+### The Contractor shall furnish the manufacturer's recommended spare parts for the first year of operation.
+
+- One trim repair kit (seat, plug or disc, and stem seals) for each valve size and trim type
+- One packing set for each valve size
+- One positioner repair/diaphragm kit for each positioner type
+- One solenoid valve and one I/P transducer of each type used
+- One diaphragm and one gasket set for each pneumatic actuator size
+
+```datasheet
+label: Spare Parts Package
+type: checkbox
+options:
+ - "Trim repair kit (each size/type)"
+ - "Packing set (each size)"
+ - "Positioner repair/diaphragm kit (each type)"
+ - "Spare solenoid valve (each type)"
+ - "Spare I/P transducer (each type)"
+ - "Actuator diaphragm and gasket set (each size)"
+default: "Trim repair kit (each size/type)"
+```
+
+### Common spare parts shall be stocked once per size/type rather than per valve where multiple identical valves are installed.
+
+### The spare-parts list with manufacturer part numbers shall be included in the closeout documentation.