Flange Globe Valve Types and How It Works

Types of flange globe valves 

T-pattern flange globe valve 

This valve is also known as a standard pattern valve. The valve design is the most common. It comes with a flat seat to allow the stem and disc to move perpendicular to the flow direction. This design leads to low fluid flow resistance compared to other versions of flange globe valves. Also, this valve design has the lowest flow coefficient and a high-pressure drop. Flange globe valve manufacturers recommend this valve for use in severe throttling applications. It is also suitable for use where pressure drop is not a significant concern and throttling is the main requirement.

Figure: T-pattern flange globe valve.

Angle pattern flange globe valve 

This valve is designed to align inlet and outlet ports at an angle of 90^o degrees. As such, the flow in these valves occurs at the same 90^o degree turn. These valves have a low coefficient of fluid flow compared to the Y-pattern valves. They are suitable for use where there are periods of pulsation flow because they can withstand the slugging effect of a pulsating flow. The valve offers an exceptional advantage where a valve is needed between two pipe bends. In a pipe bend, the valve will provide low flow resistance relative to the standard valve. Also, this valve will reduce the number of pipe joints and thus save on pipe elbow.

Figure: Angle-pattern flange globe valve.

Y-pattern flange globe valve 

Y-pattern flange globe valves are widely used for regulating flow during startup or seasonal operations. This is the flange globe valve designed to angle the stem and seat at 45^o degrees. This design offers straight-fluid flow when the valve is fully open. It also has the least resistance to flow when fully open. As such, flange globe valve manufacturers recommend this valve as an alternative to standard and angle pattern valves due to low-pressure drop. Also, this valve can remain open for a long time without suffering severe erosion. Cleaning the valve interior is done by opening the bonnet.

Figure: Y-pattern flange globe valve.

Electric flange globe valve 

This valve operates by using an electric motor. The electric motor is powered by electricity. When the valve is turned on, the electric motor shaft rotates, producing mechanical energy. The mechanical energy of rotary motion is transmitted to the valve disc via the stem. As such, the valve stem turns, causing the disc to move up or downwards to open or close fluid flow. These valves are easy to clean and repair. They are also cheaper to repair. Flange globe valve manufacturers design this valve to operate as fully automated or semi-automated. The fully automated version does not need human intervention to open or close fluid flow. This valve is very clean, unlike the hydraulic actuated valve prone to hydraulic oil and dirt. Due to its cleanliness, this valve is recommended for use in applications such as foods and beverages that demand high hygiene levels.

Figure: Electric flange globe valve.

Pneumatic flange globe valve 

The pneumatic flange globe valve operates using a pneumatic actuator. A pneumatic actuator operates by using compressed air. The compressed air acts on a piston causing rotary motion. The rotary motion is transmitted to the valve stem causing the stem to rotate while the disc moves up or down to open or close fluid. This valve is highly reliable for both automation and semi-automation applications. The air used in the actuator can be cleaned, making the valve suitable for use in applications like pharmaceuticals and foods that demand high levels of hygiene.

How does a flange globe valve work? 

A flange globe valve starts, stops, and regulates fluid flow. This valve comprises a movable disc and a stationary seat on the spherical valve body. The seat is usually mounted parallel to the pipe and it is in the middle of the valve body.

To start the valve, the valve operator turns the handwheel clockwise. As such, the valve stem makes similar turns in the same direction. The stem has threads that help to convert the rotary motion into linear movement. As the stem moves upwards, the disc also moves upwards. This upward movement of the disc leaves the valve open, allowing fluid to flow through the valve. To close the valve, the operator turns the handwheel in the counterclockwise direction. As such, the stem rotates in the same direction as it moves downwards. Consequently, the valve disc starts moving downwards until it fully seals off the fluid flow path and stops any flow. For throttling, the handwheel is turned slightly causing the disc to open partially depending on the flow rate the operator needs.

Figure: Working of a flange globe valve.