Globe Valve

What Is a Globe Valve?

When working with a plumbing configuration, it's important to have all the best components for the job. The best valves for the situation will make a huge difference in the end. In many cases, the ideal part for regulating flow is a globe valve. You've likely heard of this type, but do you actually know what is a globe valve?

How Do Globe Valves Work?

Globe valves are a type of stop valve and are commonly confused with ball valves, but they are different. A globe valve manages water flow in a pipeline. It consists of a movable plug/disc-type element and a stationary ring seat, and this is typically in a spherical body, hence globe. The plug is connected to a stem that operates through a screw action. Automatic globe valves use smooth stems, not threaded, with an actuator assembly.

Globe Valve Diagram

Here is a quick-reference globe valve diagram for easy understanding:

Types of Globe Valves

Primarily, when people talk about the type of globe valve, they mean the body style.

• Tee: also referred to as split body, fluid passes through this type of valve 180-degrees (in other words, the direction is unchanging).
  

• Wye: this type of globe valve offers the least flow resistance and changes the direction of fluid by 45 or 90 degrees.

• Angle: operates with a direction change of 90 degrees, and it's convenient because you don't need an elbow.

Body type isn't the only consideration. There are needle globe valves, outside screw stems, inside screw stems, plug discs (AKA plunger globe valves), and even the bellow variety.

Difference Between Globe Valves and Gate Valves

Globe valves and Gate valves both belong to the most common valves that are used in industrial plants since both are designed by the Valve Manufacturers in such a way that they keep the systems running as efficiently and safely as possible. They have their unique designs which primarily help facilitate their own applications.

Globe Valves :

The Globe valves are a member of the linear motion valve family which are designed for many industrial applications, including the oil and gas industry. These valves are similar to the gate valves and a use linear motion for the throttle flow. Its functions include start and stop of media as well as regulate the flow it within the pipe. Owing to their design i.e. made with a spherical body and a disc they provide a tighter seal with maximum leakage stopping.

The Global Valve Supplier often prefer these valves as they are perfectly suitable for applications where the main concerns are safety and leaks. A superior advantage of a globe valve is that it does not leak as much as other valves. The vertical disc movement within the globe valve is specifically designed to give these valves a good throttling ability thus allowing them to regulate flow within a pipeline. These valves can also function as control valves hence commonly used for highly viscous media, corrosive media and systems of higher-pressure and higher-temperature.

Gate Valves :

The Gate valves are designed to have the gate faces that are parallel/wedge shaped disc with a rising/a non-rising stem in most of the cases. The basic operation is that the gate disc moves upwards to open the valve thus providing little pressure drops since there is no obstruction in the way of media flow. Also it closes by moving the disc downwards to meet with the seats. Known to have lower pressure drops these valves are offer little resistance to fluid flow, especially in the fully open position. Above all the gate valves can be set in any directional flow which is why they are strongly suggested by the Gate Valves Supplier to customer of varied industries.

Their Structural Design :

Globe valve parts are located inside the cavity itself. Since its main purpose is to throttle and provide positive shut-off, this structural design allows that obstructions that aid the valve in this purpose. The globe has a rising stem which permits the changes in flow direction and the rate that contributes to a high-pressure drop phenomenon.

Gate valve construction is much simpler since most of its internal components are present on the top part of the valve body. They might have a rising or a non-rising stem. The body becomes hollow when it is turned on thus there is a little pressure drop.

Their Functions :

• The globe valve is primarily more of a control valve.

• The gate valve is designed for the media isolation not for the flow control.

Their Applications

• The globe valve is unidirectional and best used in applications where massive changes in pressure are not an issue.
  

• The gate valve is a multidirectional valve specifically suitable for applications where low-pressure drops are of utmost importance.

Their Working :

• The globe valve disc, on the other hand, moves parallel to the media flow. During a full flow the disc only has to move a little away from the seat.

• The gate valve working mechanism is that the is disc locked in between the seats making its movement at a right angle in relation to the media flow ensuring that it provides either fuller flow or zero flow.