Sizing a Globe Valve – How to Select the Right Valve for Your Application
Key Highlights:
Proper sizing is critical for valve performance and efficiency
Flow rate, pressure drop, and Cv (flow coefficient) must be considered
Oversized or undersized valves can cause operational issues
GlobeValve.co.uk offers expert support and a wide range of options
Accurate sizing ensures long-term system reliability
Why Sizing Matters
Globe valves are widely used for their ability to regulate flow with precision, but their performance is only as good as their sizing. A valve that is too small may restrict flow and cause excessive pressure drop, while a valve that is too large can lead to poor control, instability, and even damage to system components.
At GlobeValve.co.uk, we help engineers and buyers make informed decisions by focusing on the most important sizing factors to ensure optimum valve performance across various systems and industries.
Key Factors in Globe Valve Sizing
Flow Rate (Q)
The required flow rate of the media (typically in litres per minute or cubic metres per hour) is the first thing to establish. This helps determine the valve opening size and capacity needed to meet system demands.
Pressure Drop (ΔP)
Pressure drop across the valve is a natural result of fluid resistance. Knowing the acceptable pressure drop in your system is vital for selecting a valve that balances control and energy efficiency.
Cv Value (Flow Coefficient)
The Cv value is a key figure in valve sizing. It represents the volume of water at 60°F that will flow through a valve with a 1 psi pressure drop. Matching the valve’s Cv to your required system values ensures smooth operation.
Line Size vs Valve Size
The globe valve size doesn’t always need to match the pipe size. In throttling applications, a smaller valve is often used to improve control. It's important to evaluate whether line size or flow performance should dictate your choice.
Application Conditions
Consider media type (liquid, gas, steam), operating pressure, temperature, and whether the application is for isolation or modulation. These will affect the material, trim, and seat selection too.
Consequences of Incorrect Sizing
Incorrect globe valve sizing can lead to:
Poor flow control or instability
Excessive noise and vibration
Premature wear of internal components
Increased energy usage due to pressure loss
Higher maintenance costs or downtime
Sizing correctly from the start saves time, money, and operational headaches down the line.
Get Expert Help at GlobeValve.co.uk
We supply globe valves in a wide range of sizes, pressure ratings, and materials – including cast iron, carbon steel, and stainless steel. Whether you need a compact threaded valve for tight spaces or a full-size flanged valve for steam regulation, we’re here to help.
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Same-day dispatch across the UK
Technical support with valve selection and sizing
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