The valve shown in the illustration operates...

🔍 Key Concepts

• Study how the cam motion at the lower right (near K) is transmitted upward through the actuator. • Follow the pipe labeled G and the plunger at H to see what type of fluid is used to transmit force to the valve spindle. • Look at the spring pack at F and the valve spindle at C to decide whether the valve is forced open or closed by the cam/pressure, and which action the springs provide.

💭 Think About

• Does the cam at the bottom right push directly on the valve stem, or does it act on another piston first? Trace the mechanical path. • Is the line between the actuator and the valve body carrying air or oil, and is that pressure being used to open or to close the valve? • If the springs at the top are compressed when the valve is open, what does that tell you about whether the valve is being opened by mechanical linkage or by fluid pressure?

✅ Before You Answer

• Verify whether there is a direct pushrod from the cam to the valve stem (this would support a purely mechanical opening principle). • Check if the force from the cam is first converted into pressure on a fluid that then acts on the valve spindle (this would support a hydraulic/air opening principle). • Confirm whether the springs close the valve when pressure/cam force is removed, or whether the cam directly forces the valve closed.

The valve shown in the illustration operates by which of the following principles? See illustration MO-0066.

Direct cam action closes the valve.

Ship service air pressure closes the valve.

Hydraulic pressure opens the valve.

A cam operated mechanical pushrod opens the valve.

🔍 Key Concepts

💭 Think About

✅ Before You Answer