Ball Valve Torque Calculation

Needle valves are used to pump up sports balls such as basketballs.
••• Jupiterimages/Photos.com/Getty Images

Standard ball valves are known as quarter-turn valves. The valve stem rotates a metal ball with a hole drilled in it through a quarter-turn, or 90 degrees, to open and close the valve.

Torque

The rotation of the ball requires a certain turning moment, or torque, which depends upon factors such as pressure drop and fluid flow velocity. The torque requirement of a ball valve can be calculated from its breakaway torque and dynamic torque.

Breakaway Torque

Breakaway torque – the turning moment required to move the ball from rest – can be calculated from the formula Tb = A (ΔP) + B. ΔP represents the pressure drop across the valve and A and B are constants determined by the type and size of ball valve.

Dynamic Torque

Dynamic torque can be calculated from the formula Td = C (ΔP). Here, ΔP is the effective pressure drop across the valve at a given temperature and C is, once again, a constant.

Related Articles

Gate Valve vs. Ball Valve
Difference Between Standard & Full Port Ball Valves
Differences Between a Ball Valve & a Butterfly Valve
How Does a Check Valve Work?
How to Calculate Viscosity
How to Calculate Flow Rate With Pipe Size and Pressure
How to Convert CV to GPM
How to Calculate Heat Loss During Pipeline Depressurization
How to Calculate Hydraulic Cylinder Tonnage
How to Calculate the Area of a Curved Surface
How to Calculate Drum Volume
How to Calculate Pneumatic Cylinder Force
How to Calculate Pipe Size From Flow Rate
How to Calculate GPM from PSI for Water
Types of Mixing Valves for an Oil Furnace Boiler
How to Calculate Steam Velocity
How to Convert Diameter to Square Centimeters
The Four Forces That Influence Wind Speed & Wind Direction
How to Convert RPM to Feet per Minute

Dont Go!

We Have More Great Sciencing Articles!