24 Inch Butterfly Valve Selection Guide For Industrial Use

A 24-inch butterfly valve is a quarter-turn flow control device designed to handle large volumes of liquid or gas with minimal pressure drop. In industrial settings—from municipal water treatment and power plants to chemical refineries, oil and gas facilities, and manufacturing lines—these valves serve as vital components for on/off isolation, throttling, and safety interlocks under demanding conditions.

Choosing the right 24-inch butterfly valve ensures reliable performance, compliance with industry standards, and cost savings by preventing leaks, reducing downtime, and minimizing maintenance. To navigate the many factors—application demands, fluid properties, pressure ratings, material compatibility, actuation methods, and supplier credentials—this guide breaks the selection process into twelve clear steps:

• Define your industrial application requirements

• Characterize process fluid properties

• Determine pressure and temperature ratings (ASME B16.34)

• Choose between resilient-seated and high-performance designs

• Select the correct body style (wafer vs. lug)

• Evaluate seat and seal material options

• Determine actuator and operator needs

• Review valve dimensions and installation considerations

• Verify quality standards, testing, and certifications

• Compare suppliers and sourcing options

• Finalize specifications and place your order

• Plan for installation, commissioning, and maintenance

  By following these steps—starting with a precise definition of your application requirements—you’ll gain confidence in specifying a 24-inch butterfly valve that meets your operational, safety, and budgetary objectives. Let’s begin with Step 1: defining your industrial application requirements.

  STEP 1: DEFINE YOUR INDUSTRIAL APPLICATION REQUIREMENTS

  Start by pinpointing exactly what role the 24 inch butterfly valve

  will play in your process. A clear understanding of application requirements prevents overspecification, avoids premature wear, and ensures that the selected valve meets safety and performance targets over its service life. Begin by listing core valve functions and environmental factors before drilling down into more detailed parameters.

  Common valve functions include:

• On/off isolation

• Throttling and flow control

• Check service (preventing reverse flow)

• Pump control (bypass, start/stop)

• Fire-safe duty (fusible link activation)

  Environmental considerations can make or break a valve’s longevity:

• Installation location: indoor shelter vs. outdoor exposure

• Temperature extremes: subzero starts, intermittent or continuous highs

• Chemical exposure: corrosive atmospheres, UV, dust or particulate load

Identify the Industrial Application Type

Your choice of valve should align with the industry’s unique demands. Common categories and their typical concerns are:

• Potable water / Water treatment

  • Sanitary or NSF-61 compliance, low-leakage seats

  • Chlorine resistance, frequent cycling for backwash

• Wastewater / Sewage

  • Handling solids and debris, abrasion-resistant surfaces

  • Corrosion from hydrogen sulfide or other gases

• Chemical processing

  • Acid or caustic compatibility, PTFEor specialty elastomers

  • Tight control for precise dosing

• Oil & Gas

  • High-pressure service, explosion-proof actuators

  • Fugitive emission controls, API 609 or API 594 conformance

• HVAC / Chilled water

  • Moderate pressures, low noise, steam-trap bypass

  • Space constraints for gear operators in mechanical rooms

• Power generation

  • Elevated temperature lines (steam, condensate)

  • Rapid actuation for turbine bypass or emergency shutdown

Determine Flow Characteristics and Performance Needs

Accurately sizing a butterfly valve hinges on matching flow rate and pressure drop to the valve’s published Cv (flow coefficient). Cv represents the number of gallons per minute (GPM) of water at 60 °F that will pass through the valve with a 1 psi pressure drop.

To calculate Cv:

Where Q is flow rate (GPM) and ΔP is pressure drop (psi).

Actionable example: For a 24-inch line handling 2000 GPM at a 10 psi drop:

• sqrt(10) ≈ 3.162

• Cv ≈ 2000 ÷ 3.162 ≈ 632

  Once you know the required Cv, compare it to manufacturer curves or tables to ensure the butterfly valve operates in a linear or defined range for throttling.

  ESTABLISH OPERATIONAL DEMANDS AND DUTY CYCLE

  How often and how quickly a valve cycles affects actuator choice, wear rates, and maintenance intervals. Key factors include:

• Cycle frequency: manual operations (few per day) vs. automated cycling (dozens per hour or more)

• Actuation speed: standard quarter-turn vs. rapid closure for emergency shutdown

• Duty type: continuous throttling, batch isolation, pulse services

• Safety interlocks: integration with PLCs, fail-safe spring return or emergency power cut

  Accounting for these demands up front will help you specify gear ratios, actuator sizing, and any special accessories like positioners or limit switches.

  APPLICATION SCENARIO EXAMPLE

  Consider a municipal water treatment plant where a 24-inch butterfly valve is needed for a pump bypass loop:

• Flow rate: 1800–2200 GPM

• Operating pressure: 80 psi normal, up to 100 psi surge

• Fluid: potable water with periodic chlorination

• Duty cycle: automated, roughly 12 open/close cycles per hour during backwash

• Actuation: pneumatic cylinder with spring-return for fail-close on power loss

• Environment: outdoor vault, temperature −20 °F to 120 °F, UV and rain exposure

  By laying out these parameters—flow, pressure, cycle rate, actuation method, and environmental factors—you can move confidently into Step 2: selecting materials that tolerate the fluid and site conditions.

  STEP 2: CHARACTERIZE THE PROCESS FLUID PROPERTIES

  Accurately defining your process fluid’s properties is essential for selecting valve body materials, seat compounds, and seal designs that resist corrosion, erosion, and chemical attack. A mismatch here can lead to premature wear, leakage, or total valve failure. The most critical fluid characteristics to document are viscosity, pH, temperature, solids content, abrasiveness, and chemical aggressiveness.

  Key fluid properties to consider:

• Viscosity

• pH and chemical composition

• Temperature (continuous and intermittent)

• Solids content and particle size

• Abrasiveness and corrosion potential

Assess Fluid Temperature Range

Temperature extremes directly impact both the valve body and elastomeric seals or gland packing. First, determine the continuous operating temperature and any intermittent spikes (e.g., steam cleaning or process upsets). Then match these ranges against material limits:

• Valve body materials:

  • Carbon steel (−20 °F to 400 °F)

  • 316 stainless steel(−50 °F to 800 °F)

  • Duplex or alloy steels for higher temperatures or more severe conditions

• Seat and seal compounds:

  • EPDM (−20 °F to 250 °F)

  • BUNA-N (0 °F to 200 °F)

  • Viton®/FKM (−10 °F to 400 °F)

  • PTFE (−100 °F to 450 °F)

    For intermittent excursions, select materials with a safety margin of at least 20% above the highest expected temperature to avoid swelling, embrittlement, or degradation.

    DETERMINE FLUID PH AND CHEMICAL COMPATIBILITY

    The acidity or alkalinity of your process fluid—and any dissolved or suspended chemicals—dictates which metals and elastomers will resist attack:

• pH < 4 (strong acid): consider stainless steels (316, 317L), PTFE seats

• pH 4–9 (mild to neutral): carbon steel with EPDM or BUNA-N seats often suffice

• pH > 9 (strong alkali): stainless steel or specialty alloys, PTFE or PVDF seats

  Always consult a chemical-resistance chart: locate your fluid’s key constituents (e.g., HCl, NaOH, solvents) and identify compatible valve body and seat materials. If fluid composition varies, choose the most aggressive case to size for worst-case corrosion allowance.

  EVALUATE SOLIDS CONTENT AND PARTICLE SIZE

  Abrasion from suspended solids accelerates wear on disc edges, seats, and body bores. When particle loading or slurry conditions exist:

• Quantify solids concentration (e.g., percent by weight) and particle size distribution.

• For light debris (< 50 ppm, fine silt), resilient seats with hardened coatings may work.

• For heavy slurries (> 2% solids, sand/grit), consider:

  • Double-eccentric valveswith PTFE or metal seats

  • Hard-faced discs (stainless or coated)

  • Regular flushing or purge ports to clear settled particles

    Selecting a design with replaceable seats or corrosion-resistant liners will extend service intervals and simplify maintenance.

    EXAMPLE: SLURRY SERVICE CONSIDERATIONS

    Imagine a 24-inch butterfly valve handling a 5% by weight sand-water slurry in a mining washplant:

• Solids size up to 150 µm, high abrasion risk

• Temperature: 70 °F continuous

• pH neutral (7) but contains trace chlorides

  Recommended approach:

• Body: duplex stainless steel or carbon steel with hard ceramic coating on internal surfaces

• Disc: 316 stainless steel with tungsten carbide overlay at the leading edge

• Seat: PTFE for chemical neutrality plus abrasion resistance

• Maintenance: install a bypass line for periodic high-flow flush and schedule quarterly inspections

  By matching body and seat materials to both chemical and abrasive conditions—and planning for routine flushing—you’ll maintain tight shutoff and prolong valve life in demanding slurry service.

  With fluid properties characterized, you can confidently proceed to Step 3: determining the proper pressure and temperature ratings per ASME B16.34.

  STEP 3: DETERMINE PRESSURE AND TEMPERATURE RATINGS USING ASME B16.34

  Pressure and temperature ratings establish the safe operating limits of a butterfly valve. Underrating a valve can lead to seal failure or body deformation, while overrating can inflate costs unnecessarily. ASME B16.34 is the industry benchmark for flanged, threaded, and welding-end valves, providing pressure–temperature tables for different materials and pressure classes. Referencing this standard ensures your 24-inch butterfly valve matches both the process conditions and safety factors required by code.

  REVIEW ASME B16.34 PRESSURE-TEMPERATURE CHART

  The ASME B16.34 standard (https://www.asme.org/codes-standards/find-codes-standards/b16-34-valves-flanged-threaded-welding-end/2020/nondrm-enabled-pdf) includes detailed charts indicating maximum allowable working pressures (MAWP) for each material and class at various temperatures. For example, a carbon steel valve in Class 150 has reduced pressure capacity as temperature rises. An excerpt of Class 150 ratings for carbon steel is shown below:
  ||Temperature (°F)||Allowable Pressure (psi)|
  |100|285|
  |200|260|
  |300|235|
  |400|210|
  |500|180|
  Use the full ASME chart to verify the MAWP at your highest continuous service temperature. If your process experiences periodic spikes above the continuous range, select the rating corresponding to that peak.

  SELECT THE APPROPRIATE PRESSURE CLASS

  Butterfly valves come in several ANSI and AWWA Classes(for potable and water treatment). Matching the correct class to your operating pressure provides a built-in safety margin:

• ANSI Classes

  • 125#: up to 125 psi at ambient

  • 150#: up to 150 psi at ambient

  • 300#: up to 300 psi at ambient

• AWWA Classes

  • 75B: up to 75 psi

  • 150B: up to 150 psi

  • 250B: up to 250 psi

    When choosing, consider both the normal operating pressure and a safety margin (commonly 10–20%). For example, a system running at 130 psi would typically use a Class 150 valve rather than pushing a Class 125 up to its limit.

    ACCOUNT FOR DIFFERENTIAL AND SURGE PRESSURES

    Normal operating pressure is only part of the story. Transients—such as water hammer from pump trips or quick valve closures—can generate significant pressure spikes:

• Steady-state pressure: the continuous pressure under normal conditions

• Surge (water hammer): short-duration spikes that can exceed steady-state by 25–50%

  To guard against these events:

1. Estimate surge magnitude using system hydraulics or pump curves.

2. Add surge allowance (typically 20–30 psi) to your design pressure.

3. Choose a pressure class whose MAWP at your fluid temperature exceeds this combined value.

   By factoring in both continuous and surge pressures, your 24-inch butterfly valve will maintain integrity during start/stop cycles, emergency shutdowns, and unexpected transients—keeping your system safe and reliable.

   STEP 4: CHOOSE THE RIGHT VALVE DESIGN—RESILIENT VS HIGH-PERFORMANCE

Butterfly valvescome in two primary designs: resilient‐seated models that use an elastomer liner for tight shutoff, and double‐eccentric high‐performance valves that rely on metal‐to‐metal or advanced seal geometries for improved wear resistance and throttling control. Selecting between these options involves weighing upfront cost, leakage tolerance, maintenance requirements, and accuracy in flow control.

Resilient-Seated Butterfly Valve Features (Series 1300)

Valtorc’s Series 1300 high‐flow resilient‐seated butterfly valves are engineered for general service applications where moderate pressures and tight shutoff are required at a budget-friendly price point. The elastomeric lining provides a bubble-tight seal against low‐pressure leaks, and the streamlined body minimizes pressure loss.

Key features of the Series 1300 include:

• Available in wafer and lug body styles for flexible installation

• ANSI Class 125# and 150# pressure ratings

• Manual lever handle on sizes ≤ 12″; gearbox operator for larger diameters

• Low‐profile disc and body design for high Cv and minimal turbulence

• EPDM, BUNA-N, or optional Viton® seat materials for broad chemical compatibility

  For full specifications, see the Series 1300 high‐flow resilient‐seated butterfly valves specs.

  DOUBLE ECCENTRIC HIGH-PERFORMANCE VALVE FEATURES (SERIES 1200)

  When your process demands higher pressures, tighter throttling control, and extended service intervals, Valtorc’s Series 1200 double‐eccentric valves deliver. The offset shaft and disc geometry reduce wear on the seat, while a self‐energizing lip seal maintains consistent compression as pressure fluctuates.

  Series 1200 highlights:

• Offered in wafer or lug configurations, ANSI Class 150# and 300#

• ISO 5211 top flange for direct mounting of actuators or gearboxes

• Flexible lip seal design that leverages media pressure to enhance sealing

• Metal‐reinforced disc edge and heavy‐duty shaft bearings for abrasive service

• Smooth flow path and optional PTFE‐encapsulated seats for chemical resistance

  Detailed information is available in the double‐eccentric high‐performance butterfly valves specs.

  COMPARE DESIGN ADVANTAGES AND LIMITATIONS

  Below is a side-by-side comparison of resilient-seated and high-performance butterfly valves to help you match design attributes to your application needs:
  ||Feature||Resilient‐Seated (Series 1300)||Double‐Eccentric (Series 1200)|
  |Seat Material|Elastomer (EPDM, BUNA-N, Viton)|PTFE, flexible lip seal|
  |Leakage Rate (bubble tight)|Yes|Yes, plus metal‐to‐metal backup|
  |Pressure Rating|ANSI 125/150#|ANSI 150/300#|
  |Cost (initial)|Lower|Higher|
  |Maintenance Interval|Moderate (seal replacement)|Extended (seal self‐energizes)|
  |Throttling Accuracy|Basic control|Precise, linear range|
  |Abrasion Resistance|Moderate (soft seat)|High (hard disc edge)|
  |Actuation Options|Manual lever or gearbox|ISO 5211 direct mount|
  Resilient‐seated valves excel in water treatment, HVAC, and general on/off isolation where cost and simplicity are priorities. Double‐eccentric high‐performance valves shine in chemical dosing, steam service, and abrasive or high‐pressure environments where long life and accurate throttling are critical.

  STEP 5: SELECT BODY STYLES AND ENSURE ANSI/AWWA COMPLIANCE

  Choosing the right body style for your 24-inch butterfly valve not only affects installation and maintenance but also determines whether the valve can safely meet industry standards. Wafer and lug designs each offer unique advantages—and limitations—when it comes to mounting, flow direction, and dead-end service. At the same time, rubber-seated valves intended for water and wastewater applications must conform to AWWA C504 performance and testing requirements. In this step, we’ll walk through body style selection, key compliance criteria, and how to align your choice with Valtorc’s product offerings.

  WAFER VS LUG STYLE: INSTALLATION AND SERVICE DIFFERENCES

  Wafer-style butterfly valves are the most compact option, sandwiched between two flanges with only the flange bolts providing alignment. They’re inherently bi-directional and well-suited for tight piping layouts, but not recommended for dead-end isolation since downstream support relies on the mating flange.

  Lug-style valves feature threaded lugs around the perimeter of the body. Each flange bolt threads into a lug, allowing removal of one side of the pipeline without disturbing the opposite flange. This makes lug valves ideal for dead-end service or for isolating downstream piping—especially important when you need to perform maintenance or repairs without shutting down an entire line.

  CHECK AWWA C504 PERFORMANCE AND TESTING REQUIREMENTS

  If your 24-inch valve is destined for potable water or wastewater service, it must meet the rigorous criteria of AWWA C504. This standard covers rubber-seated butterfly valves in sizes 3″ through 144″ and defines mandatory tests, including:

• Hydrostatic body test at 1.5× rated pressure to verify no leakage through the body or bonnet

• Seat leakage test at rated pressure, allowing only minimal permissible leakage per cycle

• Endurance cycling (open/close) to ensure consistent performance over time

  For valves 24″ and larger, AWWA C504 requires extended seat-leakage testing (five consecutive cycles) and a 15-minute body test. Always request certified test reports or witnessed testing to confirm compliance.

  CONFIRM FLANGE COMPATIBILITY AND REFER TO VALTORC’S OFFERINGS

  Flange drilling must match ANSI B16.5 dimensions for your chosen pressure class. A 24″ Class 150 lug valve, for example, typically uses 12 bolts on a 28.50″ pitch circle, with bolt diameters around 7/8″. Verify bolt count, size, and gasket style against your system’s flange rating to ensure a leak-tight joint.

  For a complete overview of Valtorc’s wafer and lug butterfly valves, visit the butterfly valve overview. There you’ll find detailed flange charts, gasket recommendations, and installation accessories tailored to ANSI and AWWA standards.

  EXAMPLE: SPECIFYING LUG-STYLE FOR DEAD-END SERVICE

  Imagine you need a 24″ lug-style butterfly valve to isolate downstream piping on a 150 psi water line:

1. Body style: lug, ANSI Class 150, ductile iron

2. Seat material: EPDM (potable water compatibility)

3. Flanges: ANSI B16.5 Class 150 drilling, 12 × 7/8″ studs

4. Gasket: spiral-wound with 304 SS windings and 304/316 L filler

5. Bolt torque: follow ANSI B16.5—typically 70–90 ft-lb in a star pattern

   With this specification, you can install the valve between two flanges and—when servicing the downstream section—remove only the outlet bolts, leaving the upstream side bolted and sealed. That minimizes downtime and avoids full-line depressurization.

   STEP 6: EVALUATE SEAT AND SEAL MATERIAL OPTIONS

   Choosing the right seat and seal materials is essential for reliable shutoff, long service life, and minimal maintenance. Material compatibility affects not only leakage performance but also how a 24-inch butterfly valve withstands temperature swings, chemical attack, and abrasion. In this step, we’ll review common elastomer and polymer seats, explore advanced seal geometries for high-performance valves, and summarize the working limits you need to know.

   SEAT MATERIAL SELECTION—EPDM, BUNA-N, PTFE, AND OTHERS

   Valve seats come in a variety of compounds, each offering a distinct balance of temperature tolerance, chemical resistance, and wear life. The table below highlights the most widely used materials in industrial butterfly valves:
   ||Material||Temperature Range (°F)||Chemical Resistance||Abrasion Tolerance|
   |EPDM|–20 to 250|Excellent with acids, caustics, steam, water|Moderate|
   |BUNA-N|0 to 200|Good with oils, hydrocarbons, light solvents|Moderate|
   |Viton® (FKM)|–10 to 400|Excellent with oils, fuels, most solvents|Moderate|
   |PTFE|–100 to 450|Outstanding across nearly all chemicals|High|
   |Neoprene|–20 to 250|Fair with oils, ozone, weathering|Low–Moderate|
   EPDM and BUNA-N seats are cost-effective choices for water, steam, and oil applications, while Viton® handles higher temperatures and aggressive solvents. PTFE seats—often encapsulated around a metal core—deliver the broadest chemical compatibility and superior abrasion resistance, making them ideal for harsh chemical or slurry services.

   SEAL DESIGNS—LIP SEAL AND FLEXIBLE-SEAL CONCEPTS

   Beyond the seat compound, the sealing geometry plays a pivotal role in performance. High-performance butterfly valvesoften employ a self-energizing lip or flexible-seal design. Here’s how they work:

• Self-Energizing Lip Seal: The lip is preloaded against the disc. As line pressure rises, it forces the lip tighter into the sealing surface, improving leak resistance without increasing operating torque.

• Flexible-Seal Concept: A segmented or molded ring that flexes around the disc edge, accommodating minor misalignments and wear while maintaining uniform contact.

  Benefits of these advanced seal designs include:

• Low and consistent torque, even after seat wear

• Bubble-tight shutoff under varying pressures

• Reduced maintenance since pressure compensates for minor damage

• Enhanced longevity in throttling and frequent-cycle applications

Temperature and Pressure Limits by Material

It’s important to match seat compounds to both the maximum process temperature and the pressure class of your valve. The simplified chart below shows typical working limits for ANSI Class 150 butterfly valves:

*Max Pressure based on standard ANSI Class ratings. Consult ASME B16.34 for de-rating curves at elevated temperatures.

If your system operates near these limits—or if you require Class 300 service—verify the vendor’s pressure–temperature curves for each material. Selecting a seat that exceeds your highest expected temperature by at least 20% adds a safety margin against compound degradation.

With seat and seal materials chosen to match your chemical, thermal, and pressure demands, you’re ready to tackle Step 7: determining the right actuator and operator configuration for your 24-inch butterfly valve.

Step 7: Determine Actuator and Operator Requirements

Selecting the right actuator or operator is critical to ensure your 24-inch butterfly valve moves smoothly, meets cycle demands, and integrates with your control system. You’ll weigh manual simplicity against automated precision, and size the actuator to handle the torque generated by your process conditions.

Manual Operators—Lever Handles and Gearboxes

For valves that open and close infrequently—perhaps once or twice a day—a simple lever handle can suffice. Typically applied on valves up to 12″, lever handles provide a quick quarter-turn action but offer limited mechanical advantage on a 24″ disc