Valve Leakage Rate Calculation: Units, Test Context, and Practical Limits
The Short Answer Valve leakage rate calculation converts a measured leakage—through the closed seat, past the packing, or across the […]
Drawings & Calculations
Valve Calculations
Valve calculations turn service conditions into engineering numbers: flow coefficient, torque, pressure drop, actuator force, and sizing are all part of specifying a valve correctly. This tag collects articles on flow coefficient and its application, handwheel torque and gearbox calculations, actuator force requirements, and pressure-drop and velocity considerations for piping systems. Content walks through worked examples and practical formulas for selecting and verifying valves, with emphasis on getting the inputs right. Written for engineers who need calculation guidance they can apply directly to their projects.
Drawings & Calculations
Valve Opening Angle vs Flow Characteristic: What the Curve Really Tells You
The Short Answer Valve opening angle and flow characteristic describe two different things: the opening angle is the physical travel […]
Drawings & Calculations
Valve Sizing for Steam: Cv, Velocity, and Pressure Drop Calculations
The Short Answer Steam valve sizing differs from liquid sizing because steam is compressible and its density changes with pressure […]
Drawings & Calculations
Cv to GPM Conversion: Formula, Examples, and When It Applies
The Short Answer The flow coefficient Cv and the flow rate in gallons per minute (GPM) are linked by the […]
Drawings & Calculations
Valve Cv Calculation Formula: How to Compute Flow Coefficient Correctly
The Short Answer The valve flow coefficient Cv is a number that expresses how much fluid a valve passes at […]
Drawings & Calculations
Valve Sizing for Gas Choked Flow: When Flow Stops Following the Pressure Drop
The Short Answer Gas flowing through a valve reaches choked (critical) flow when the downstream pressure falls low enough that […]
Drawings & Calculations
Actuator Torque Calculation Formula: How to Size a Valve Actuator
The Short Answer Actuator sizing starts from the valve’s required breakaway torque or thrust, multiplied by a safety factor and […]
Drawings & Calculations
Valve Stem Load Calculation: Pressure Force, Packing, and Seat Load
The Short Answer Valve stem load is the total axial force the stem must carry, and it is the number […]
Drawings & Calculations
Actuator Sizing Calculation: Five Steps From Valve Torque to Actuator Output
The Short Answer Actuator sizing is a five-step process: define the valve’s breakaway torque, add running torque and any thrust […]
Drawings & Calculations
Cv vs Kv Valve Flow Coefficient: Same Capacity, Different Units
The Short Answer Cv and Kv are both flow coefficients that describe how much fluid a valve passes at a […]
Drawings & Calculations
Valve Flow Calculation: Q = Cv x sqrt(dP/SG) Explained with Examples
The Short Answer Flow through a valve follows a simple square-root law for liquids: flow is proportional to the valve’s […]
Drawings & Calculations
Valve Cv Calculation: Formula, Worked Example and Sizing Steps
The Short Answer Cv, or flow coefficient, is a number that describes how much fluid a valve will pass at […]
Drawings & Calculations
Valve Leakage Class Explained: Limits, Testing and How to Specify
The Short Answer Valve leakage class is a standardized way of expressing how much leakage a valve may pass when […]
Drawings & Calculations
Hydrostatic Test Pressure Calculation: How It Works and How to Do It
The Short Answer Hydrostatic test pressure is calculated from the component’s design pressure or pressure rating, multiplied by a code-specific […]
Drawings & Calculations
Pressure Relief Valve Sizing Calculation: A Step-by-Step Overview
The Short Answer Pressure relief valve sizing is the process of determining the relieving area the valve needs to discharge […]
Drawings & Calculations
Valve Sizing Calculation Steps: How to Size a Valve Correctly
The Short Answer Valve sizing is the process of selecting the valve size and trim that will pass the required […]
Drawings & Calculations
Valve Torque Calculation: A Practical Guide for Actuator Sizing
The Short Answer Valve torque is the rotational force required to operate a quarter-turn valve, and actuator selection depends on […]
Drawings & Calculations
Pipe Velocity vs Valve Sizing: What Engineers Need to Know
The Short Answer Pipe velocity and valve sizing are linked but serve different purposes. Pipe velocity is a piping design […]
Drawings & Calculations
Control Valve Sizing Basics: Why Size Matters and How the Process Works
The Short Answer Control valve sizing is the process of matching a valve’s flow capacity (Cv) to the required flow […]
Drawings & Calculations
Valve Flow Coefficient (Cv) Explained: What It Measures and How to Read It
The Short Answer Cv is a valve’s flow coefficient — a number that expresses how much flow a valve passes […]
Drawings & Calculations
How to Calculate Cv for Liquid vs Gas: What Changes and Why
The Short Answer The flow coefficient Cv is used to size valves for both liquids and gases, but the two […]
Drawings & Calculations
Valve Cv vs Kv: Converting Flow Coefficients Without Guesswork
Valve Cv vs Kv: Converting Flow Coefficients Without Guesswork Every control valve datasheet quotes a flow coefficient, but it may […]
Drawings & Calculations
Valve Pressure Drop: How to Calculate and Reduce It
Quick Answer Valve pressure drop is the loss of pressure as fluid passes through a valve, caused by friction and […]
Glossary
What Is Valve Flow Characteristic? Linear, Equal Percentage, and Quick Opening
Quick Answer: What Is Valve Flow Characteristic? Valve flow characteristic describes how the flow rate changes as the valve opens […]
Drawings & Calculations
Manual Valve Operation: Handwheel Torque and Gearbox Calculations
Quick Answer: How to Calculate Handwheel Torque for Manual Valves Manual valve operating torque is calculated as the sum of […]