What is the purpose of the torque limit...

Question 1 / 2707066636ef128f7522a1c523017

Question 1 of 2707066636ef128f7522a1c523017

What is the purpose of the torque limit switch as fitted on an electric motor operated rising stem gate valve?

Question 1 of 27070

What is the purpose of the torque limit switch as fitted on an electric motor operated rising stem gate valve?

🔍 Key Concepts

• Torque limit switch function in motor-operated valves • Difference between protecting the motor versus the valve/valve stem • Effect of a foreign object / obstruction on opening vs closing travel

💭 Think About

• When a valve stem is blocked by an obstruction, which component is more likely to be overloaded first: the motor or the mechanical parts of the valve? • In practice, does a torque limit switch usually respond to excessive mechanical resistance (torque) or to position of the valve (travel) – and which failure (open or close) is more critical for damage? • Think about what happens to the current drawn by the motor and the force on the stem when the valve stops moving but the motor keeps trying to turn.

✅ Before You Answer

• Be clear on whether a torque limit is designed to sense mechanical load (resistance) or end-of-travel position • Decide which is usually more expensive/critical to protect: the electric motor or the valve body/stem and seats • Consider whether the same type of damage risk exists when the valve is prevented from opening versus when it is prevented from closing

Question 1 of 27070

What is the purpose of the torque limit switch as fitted on an electric motor operated rising stem gate valve?

The torque limit switch protects the valve from being damaged if a foreign object prevents the valve from fully closing.

The torque limit switch protects the motor from being damaged if a foreign object prevents the valve from fully closing.

The torque limit switch protects the motor from being damaged if a foreign object prevents the valve from fully opening.

The torque limit switch protects the valve from being damaged if a foreign object prevents the valve from fully opening.

Question 1 / 2707066636ef128f7522a1c523017

Question 1 of 2707066636ef128f7522a1c523017

What is the purpose of the torque limit switch as fitted on an electric motor operated rising stem gate valve?

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Question 1 of 27070

What is the purpose of the torque limit switch as fitted on an electric motor operated rising stem gate valve?