Email: [email protected]
Add: #407 Rongxing Rd, Shanghai, China
Wechat: +86 199 2125 0077
WhatsApp: +86 185 1656 9221
thintank control valve manufacturer

Share optimized solutions, professional valve knowledge and industry news

Please enter the relevant terms or keywords you need to consult, and relevant articles will appear in the search results. If you can’t find the answer you need, please feel free to contact us and we will be happy to help. Or you can directly send an email to [email protected]

CV Value Calculator

Table of Contents
    Add a header to begin generating the table of contents

    The CV value in the context of a valve refers to the valve’s flow coefficient. It is a measure of the capacity of the valve to flow a fluid under specific conditions. The CV value is used to quantify the flow rate of fluids (liquids and gases) through a valve at a given pressure drop across the valve. The higher the CV value, the higher the flow rate that can pass through the valve with a given pressure drop.

    The formal definition of the CV value is the number of US gallons of water at 60°F that can flow through the valve per minute with a pressure drop of 1 psi across the valve. It is a crucial parameter for selecting the appropriate valve for a particular application, ensuring that the valve can handle the required flow rate without causing excessive pressure drop or flow restrictions.

    what is valve cv

    The valve Cv means valve flow coefficient, is a crucial parameter in fluid dynamics that quantifies the flow capacity of a valve. It represents the volume of water in U.S. gallons that can pass through a valve per minute at a temperature of 60°F with a pressure drop of 1 psi across the valve. Essentially, the Cv value provides an indication of how much fluid can flow through a valve, thereby helping in selecting the right valve for specific flow requirements in various applications, such as in piping systems, HVAC, water treatment, and more.
    The higher the Cv value, the greater the flow rate that can pass through the valve with a given pressure drop, indicating a larger flow capacity. Conversely, a lower Cv value indicates a smaller flow capacity, suitable for applications requiring finer control of the flow rate at lower volumes.

    Here’s a breakdown of what the CV value indicates in valve selection and operation:

    High CV Value

    A high CV value indicates a larger flow capacity. This means the valve can allow more fluid to pass through at a lower pressure drop. Valves with high CV values are suitable for applications requiring high flow rates.

    Low CV Value

    A low CV value indicates a smaller flow capacity. This means the valve restricts flow more significantly, resulting in a higher pressure drop for a given flow rate. Valves with low CV values are used in applications where flow control or restriction is needed.

    Understanding the CV value is essential for engineers and technicians to ensure that the selected valve meets the operational requirements of the system, providing adequate flow control without causing excessive pressure losses or other hydraulic issues. If you have any questions about CV Value, you are welcome to contact THINKTANK’s specilists to help you sizing your valves.

    flow coefficient cv1

    what is flow coefficient

    The flow coefficient, often denoted as Cv(in the United States) or Kv(in metric system countries), is a standardized value used to describe the flow capacity of a valve, nozzle, or other types of flow passages. It quantifies how much fluid can flow through a device, providing a measure of the device’s efficiency in allowing fluid passage under specific conditions.

    Valve CV Value Calculator: An Essential Tool for Precision Flow Management

    In the complex world of fluid dynamics and system design, precision is not just a goal; it’s a necessity. At THINKTANK, we understand the critical importance of selecting the perfect valve for each unique application. It’s not just about managing flow; it’s about optimizing efficiency, ensuring safety, and maximizing performance. That’s why we’re excited to introduce our free tool: The THINKTANK Valve CV Value Calculator.

    Developed by our team of seasoned engineers, this calculator represents a leap forward in fluid system design. It encapsulates our commitment to precision engineering, offering an intuitive, user-friendly interface that simplifies the calculation of a valve’s flow coefficient (CV). This tool is designed to empower system designers, engineers, and maintenance professionals with the ability to make informed decisions quickly and accurately.

    Key Features of the THINKTANK Valve CV Value Calculator

    Precision Engineering

    Use our well-developed tool, created from years of fluid dynamics research, to calculate the exact CV value needed for your specific application.

    User-Friendly Interface

    Designed with the user in mind, our calculator allows for easy input of critical parameters, including fluid type, temperature, pressure drop, and flow rate.


    Whether you’re working with liquids or gases, at high temperatures or under extreme pressure, our calculator adapts to a wide range of conditions.

    Instant Results

    Receive immediate calculations, enabling swift decision-making and optimization of your fluid system design.

    Educational Insights

    Not only does our calculator provide you with the necessary numbers, but it also offers insights into how different variables impact your system’s performance.

    How It Works:

    At the heart of our calculator is the CV formula, which quantifies the flow rate of fluids through a valve based on a given pressure drop. By inputting your system’s specifics, our tool calculates the CV value required for optimal performance. This process demystifies valve selection, ensuring that your system operates within its intended parameters, thus avoiding common pitfalls such as excessive wear, noise, or system failure.

    To create an calculator for CV value, we need to consider the basic formula for CV calculation. The CV value is used to determine the flow rate through a valve and is calculated based on the flow rate (Q), specific gravity of the fluid (SG), and the pressure drop across the valve (ΔP). A simplified formula to calculate CV is:

    valve cv equation
    q flow capacity equation


    • Q is the flow rate in gallons per minute (GPM),
    • ΔP is the pressure drop across the valve in pounds per square inch (PSI),
    • ΔP=Upstream P1(inlet pressure) – Downstream P2(outlet pressure)
    • SG is the specific gravity of the fluid (water = 1).

    Valve CV Calculator with Convertible Units

    Valve CV Value Calculator with Convertible Units

    Example Cv calculation for water

    To calculate the Cv value of a valve for a water flow of 25 GPM (gallons per minute) with a differential pressure of 12 psi,

    • Q = 25 GPM
    • SG = 1
    • dp = 12 psi

    To calculate the Cv value of a valve for a water flow of 25 GPM (gallons per minute) with a differential pressure of 12 psi, the Cv value is calculated to be approximately 7.22. This means that under these conditions, a valve with a Cv of 7.22 will allow 25 GPM of water to flow through it with a 12 psi pressure drop across the valve. ​

    Cv-value calculator liquids & gasses

    Cv-Value Calculator Liquids:

    Specific gravity:
    Inlet pressure:
    Outlet pressure:
    Flow rate:

    Valve Kv value:
    Valve Cv value:

    Cv-Value Calculator Gasses:

    Specific gravity:
    Air temperature:
    Inlet pressure:
    Outlet pressure:
    Flow rate:

    Valve Kv value:
    Valve Cv value:

    Difference Between Cv and Kv Flow Coefficients

    The Cv and Kv flow coefficients are essential metrics used in the valve and fluid dynamics industries to quantify the flow capacity of control valves, nozzles, and other types of fluid conduits. Despite serving similar purposes, Cv and Kv are based on different measurement systems—imperial (U.S.) units for Cv
    ​and metric units for Kv. Understanding the distinction between these two coefficients, their calculation, and conversion is crucial for accurately specifying equipment in fluid systems to ensure compatibility and efficiency across global operations.

    Cv Flow Coefficient Definition

    The Cv value represents the number of U.S. gallons of water at 60°F that can flow through a valve per minute with a pressure drop of 1 psi across it.

    • Units: U.S. gallons per minute (GPM) of water, temperature at 60°F, and pressure in psi.
    • Usage: Predominantly used in the United States and countries that utilize the imperial measurement system.
    • Purpose: Cv is used to rate the flow capacity of valves, enabling engineers to select the correct valve size for their requirements, ensuring the system operates efficiently without unnecessary pressure loss.
    valve kv

    Kv Flow Coefficient Definition

    The Kv value indicates the flow rate of water in cubic meters per hour (m³/h) that passes through a valve with a pressure drop of 1 bar.

    • Units: Cubic meters per hour (m³/h) of water, with the pressure drop measured in bar.
    • Usage: Widely adopted in countries using the metric system, making it common in international specifications and documentation.
    • Purpose: Similar to Cv, Kv is used to determine the appropriate valve size for a given application, ensuring optimal performance.

    Conversion Between Cv and Kv

    The difference in base units between Cv and Kv necessitates conversion formulas for engineers and professionals working on international projects or with equipment from different measurement system regions. The conversion is straightforward, using the following relationship:

    1Cv =1.156K


    1Kv = 0.865Cv

    This conversion is critical when selecting valves for a system designed in different units than the valve specifications. Using the correct coefficient ensures the valve will meet the system’s flow requirements without causing excessive pressure drop or flow restrictions.

    Practical Implications

    • System Design and Valve Selection: Understanding the flow capacity and correctly converting between Cv and Kv ensures that valves and other components are appropriately sized for the intended application, whether it’s for HVAC, water treatment, gas handling, or other fluid systems.
    • International Projects: For engineers and professionals working across countries with different measurement preferences, mastering both coefficients and their conversion is essential for specifying the right components, avoiding errors, and ensuring project success.
    • Efficiency and Safety: Correct valve sizing not only impacts the efficiency of a fluid system by optimizing flow and reducing energy consumption but also plays a crucial role in ensuring operational safety.

    In summary, while Cv and Kv serve the same purpose in valve and fluid flow specifications, their differences reflect the measurement systems they are based on. Accurate conversion and application of these coefficients are fundamental to the design, operation, and international collaboration on fluid handling projects.

    Instructions for Use

    1. Flow Rate (GPM): Input the flow rate through the valve in gallons per minute.
    2. Specific Gravity of Fluid: Input the specific gravity of the fluid (use 1 for water).
    3. Pressure Drop (PSI): Input the pressure drop across the valve in pounds per square inch.
    4. Calculate CV Button: Click this button to calculate the valve’s CV value. The result will be displayed below the button.

    This calculator provides a quick and easy way to estimate the CV value for valves based on the specified conditions. It’s a useful tool for engineers, technicians, and students working in fields related to fluid mechanics and valve selection.

    What is the flow coefficient

    The flow coefficient, often denoted as Cv, is a measure used to describe the flow capacity of a valve, nozzle, or other types of flow passage. It quantifies the rate at which a fluid can flow through a device. Specifically, the Cv value represents the volume of water (in US gallons) that can pass through the valve per minute at a temperature of 60°F, with a pressure drop of 1 psi across the valve.

    The flow coefficient is crucial in the design and selection of flow devices in piping systems, as it helps engineers and technicians determine whether a particular valve or nozzle meets the flow requirements of their application. By knowing the Cv, one can predict the flow rate through the device for a given pressure drop, or conversely, estimate the pressure drop for a known flow rate.

    The Cv value is determined under standardized conditions to ensure consistency and comparability between different devices. It’s particularly important in applications involving liquids, where the flow dynamics can significantly impact system performance and efficiency.

    In practical terms, a higher Cv value indicates a larger flow capacity, meaning the device can allow more fluid to pass through it at a lower pressure drop. Conversely, a lower Cv value suggests a smaller flow capacity, which might be suitable for applications requiring precise control of the flow rate at lower volumes.

    The concept of the flow coefficient is not limited to water or liquids; variations of the concept are used for gases and steam, such as the Cg and Cs coefficients, respectively. These take into account the different properties of gases and steam, such as compressibility and expansion, which affect how they flow through valves and other devices.

    Valve flow coefficient variables

    The valve flow coefficient, denoted as Cv, is determined by several variables that influence the flow rate of fluid through a valve. The Cv value itself is a measure of the capacity of a valve to pass fluid, specifically defined as the number of U.S. gallons of water at 60°F that can flow through a valve per minute with a pressure drop of 1 psi. Understanding the variables that affect the Cv value is crucial for selecting the right valve for specific flow conditions in hydraulic and pneumatic systems. Here are the key variables involved:

    1. Pressure Drop (ΔP)

    This is the difference in pressure between the inlet and outlet of the valve. The Cv
    ​value is based on a standard pressure drop of 1 psi, but actual conditions may vary, affecting the flow rate through the valve.

    2. Fluid Density and Specific Gravity (SG)

    The Cv calculation is standardized for water at 60°F, which has a specific gravity of 1. For fluids with a specific gravity different from water, the flow rate can be adjusted accordingly, as the fluid’s density affects its resistance to flow.

    3. Fluid Viscosity

    The thickness or stickiness of a fluid affects its flow through a valve. High-viscosity fluids flow more slowly than low-viscosity fluids under the same pressure drop. The standard Cv value is for water (a low-viscosity fluid), and adjustments may be needed for fluids with significantly different viscosities.

    4. Valve Type and Design

    Different types of valves (e.g., ball, gate, globe, butterfly) have different flow characteristics. The internal geometry of the valve, such as the size and shape of the flow path, affects the Cv value.

    5. Valve Opening (Position)

    The Cv value changes with the valve’s position. Many valves provide variable flow control, meaning the flow rate changes as the valve moves from fully closed to fully open. The relationship between valve position and flow capacity is often nonlinear.

    6. Flow Condition

    The condition of the flow (laminar vs. turbulent) can affect the valve’s flow coefficient. Turbulent flow typically results in a more significant pressure drop than laminar flow for the same flow rate.

    7. Temperature

    While the Cv value is standardized at 60°F for water, temperature changes can affect fluid properties like density and viscosity, thus impacting flow rates. For gases, temperature changes also affect volume and, by extension, flow rates measured in terms of mass flow or volumetric flow under standard conditions.

    These variables are essential considerations when selecting a valve for a particular application, ensuring that it can handle the required flow rate under the expected operating conditions. Engineers often use detailed Cv charts provided by valve manufacturers, which account for these variables, to select the appropriate valve size and type for their specific application.


    At THINKTANK, we’re more than just engineers; we’re innovators committed to advancing the field of fluid dynamics. Our Valve CV Value Calculator is a testament to this commitment, offering a blend of precision, ease, and insight that reflects our broader mission: to engineer solutions that not only meet but exceed our clients’ expectations.

    For more information, visit our website or contact our support team. Let THINKTANK be your partner in fluid system excellence, where precision engineering meets practical application.

    Picture of Will Don

    Will Don

    After earning my bachelor's degree in mechanical engineering from Zhejiang Normal University in 2008, l was fortunate enough to begin my career with Siemens, Fisher, and YTC, focusing on control valve accessories. Over the past dozen years, l've poured my heart and energy into understanding technology and fluid solutions for control valves.
    Now, as the marketing director for THINKTANK, a trusted branch of the Taiwan STONE valve group, I can't help butf eel proud of how far we've come. Our knowledge isn't just reaching professionals like engineer and valve distributors; it's also inspiring the next generation of automation college students.
    l genuinely hope you're enjoying our articles and finding them helpful.Your thoughts, questions, and feedback mean the world to me, so please don't hesitate to reach out to marketing[at] Whether you're a seasoned expert or just curious about the field, I'm here to connect, share, and learn together.

    All Posts »

    I am the author of this article, and also the CEO and marketing director of THINKTANK, with 15 years of experience in the industrial valve industry. If you have any questions, you can contact me at any time.

    The Latest News
    3inch natural gas regulator a216wcb thinktank

    DN80 Natural Gas Regulator Manufactured in 2018

    Yesterday, we received an inquiry for the repair of a natural gas pressure regulator. Upon checking our records, we found that this valve was manufactured ...
    Read More
    training control valve

    Training Sessions on Control Valves

    Hello Everyone, I’m excited to share some news with you all directly from THINKTANK’s official website! Over the past few months, we’ve received a myriad ...
    Read More
    arctic lng 2 liquefaction trains

    Контрольные клапаны THINKTANK в проекте Arctic LNG-2

    В THINKTANK мы гордимся нашим вкладом в проект Arctic LNG-2, что является подтверждением нашей приверженности поставке высококачественных контрольных клапанов и регуляторов. Наше участие подчеркивает нашу ...
    Read More
    control valves

    THINKTANK Control Valves in Arctic LNG-2 Project

    At THINKTANK, we take immense pride in our contribution to the Arctic LNG-2 project, a testament to our commitment to delivering high-quality control valves and ...
    Read More
    dubai seawater desalination project

    Passion Like a Beam of Light

    Passion, like a beam of light,Illuminates every ordinary soulWho strives with earnest toil,Rendering life brilliantly meaningful,With not a moment spent in vain,Defining the essence of ...
    Read More
    dn25 pn16 wcb pcv (1)

    Pneumatic Single-Seat Globe Control Valves PCV DN25 PN16

    Read More
    heat shutdown on off valve

    Valvula shut off com atuador fusível

    A válvula shut-off com atuador fusível é um dispositivo utilizado para controlar automaticamente o fluxo de fluidos em tubulações, especialmente em situações de emergência ou ...
    Read More
    c95500 nickel aluminum bronze control valve factory thinktank

    Engineering Case Studies of C95500 Nickel Aluminum Bronze Control Valves

    In modern industry, the choice of control valves is critical for ensuring the reliability, efficiency, and safety of processes. As a leading manufacturer of C95500 ...
    Read More
    atex ped certificate

    Congratulations to THINKTANK Achieve ATEX and PED Certificates For Fusible Link Safety Valve and Breather Valve Series

    As the co-founder of THINKTANK, it is with a profound sense of pride and humble excitement that I share a milestone that marks a significant ...
    Read More

    Contact Us

    With expertise in valves and rich experience in the oil&gas, chemical industry, textile mills, power plants, and sugar mills. THINKTANK has become the premier manufacturer of next-generation precision control valves.

    With a customer base that includes over 42 of the world’s leading engineering&contractors and international valve brands, THINKTANK Valves offers cost-effective valves that help our customers achieve automated process control without paying high prices.

    Why are more and more international valve brands choosing THINKTANK for OEM service?

    Brand is reputation, which not only requires high valve technology, but also great comercial support and fast response after-sales service and delivery time. They will not gamble their brand on an unknown product

    Get An Instant Quote

    Joy Preview

    Focused on Control Valves & Self-Operated Pressure Regulators For Over 30 Years

    A Good Partner Is A Lasting And Effective Investment

    Get An Instant Quote

    Direct to Control Valve Factory With Competitive Price & Reliable Quality

    Joy Preview
    Joy Preview

    Get An Instant Quote

    Just leave your name, email, and simple message or requirements, We will contact you within 1 hour.

    WhatsApp: +86 185 1656 9221

    Skype ID: sowell85

    Wechat ID: +86 199 2125 0077