Get Torque Chart - Fnw Valve Co

Torque, for butterfly valves, is the turning force needed to rotate the valve disc or hold it in position (American Water Works Association 2012). When designing a valve to withstand the torque that will be applied during operation, there are ten separate torque components to consider.

Breakaway Torque values determine the force required in N-m to open or close a valve. This value is important to determine the size of the Actuator to be chosen in case of actuation of the valve. There are various factors which affect the torque, such as size of the valve, seats, media and service.

Calculate Breakaway Torque with Tb = A (ΔP) + B. The same equation applies to Closing Torque.

Many customers ask for a 25% safety factor, so if a valve requires 100 in-lb torque to open, you would size the actuator's break torque at 125 in-lbs.

That will be your breakaway torque. For the lead screw: F = c*N where F is the static friction force, c is the static friction constant and N is the normal force. In this case you have to convert the Force to Torque Torque = Force x Lead /2pi.

First of all, it is important to measure the pressure rating of the system; this should be done with the help of a pressure gauge or other pressure measuring device. Additionally, you will need to factor in the material and size of the valve when determining the necessary torque setting.

The torque value for a given butterfly valve will depend on a number of factors, including the size and material of the valve itself. Generally speaking, larger valves must be tightened more than smaller ones since they have higher resistance to pressure.

Breakaway torque is the turning force required to initiate rotation (similar to static friction), and running torque is the turning force required to keep a system in rotation (similar to kinetic friction). This will be proportional to the mass being rotated and its moment of inertia.