Class 5 Boiler Practice Exam

From which side does the pressure come in a globe valve?

1. Above the disk

2. Below the disk

3. From the sides

4. It varies by design

The correct answer is: Below the disk

In a globe valve, the pressure comes in from below the disk. This design allows for effective regulation of fluid flow by controlling the movement of the disk, which is located above the valve seat. When the fluid enters from below the disk, it facilitates smoother operation and helps to maintain the pressure balance during the regulation process. The flow characteristics in a globe valve are such that the fluid encounters resistance primarily due to the disk, which creates turbulence and allows for throttling, making them suitable for applications requiring precise flow control. By having the inlet pressure coming from below, the valve is designed to ensure that when the disk is closed, the seat offers a tighter seal against any back pressure that may occur above it. This design consideration is crucial for maintaining the integrity and efficiency of the valve during operation, ensuring that it performs effectively within the system’s pressure parameters.