A globe control valve is a type of valve that is fundamentally used to control and regulate the flow of fluid inside a pipeline. The use of the word ‘globe’ in the name of this instrument is the because it has a spherical body shape in which the two halves of the body are separated with the help of an interior baffle. They are also sometimes called by the name of throttle valves.
Construction
As we have already discussed that the body shape of the globe control valves is that of a globe. Other components that it contains include:
- Rising stems
- Movable plug or any kind of rotatable disc element
- A stationery spiral seat
Types of body designs
- TEE pattern: Containing a Z-shaped diaphragm, this design is the most common body type of a globe valve. This type of globe valve body design is used in cases where the primary focus is throttling and pressure drop does not have much importance.
- Angle pattern: In this type, the ends are given an angle of 90° and the fluid flow takes a 90-degree turn while flowing through the valve.
- WYE pattern: The angle between the seat and stamp is somewhere near 45°, providing a straight path and allowing easy flow at the opening, resulting in the least resistance to fluid flow.
Applications
- Cooling water systems: For the regulation of water flow around the system.
- Fuel oil systems: Because here, water-tightness needs to be taken care of along with the flow.
- Feedwater
- Chemical feed
- Condenser air extraction
- Heated drains
- Boiler drains and vents
Advantages
- The globe control valves are available in different designs that cater to different needs. These variety and variations in the body designs are of great help and serve diverse purposes in different fields.
- They have a great shut off capability.
- The seats of a globe control valve are extremely adjustable and easy to operate and resurface.
- If you remove the disc from the stem, then you can use this valve as a stop check valve.
Lastly, the flow direction and pressure of the globe control valve can be adjusted according to the temperature. This means that when the temperature is low, there is more pressure under the disc. This aids in providing easy operation and also protects the equipment. However, if the temperature is high in the steam service, then pressure is shifted to above the disc. This is done so that the stem does not undergo contraction when it is cooled.
