Globe Valve Parts And Types

As the name indicates, the Globe valve is a globe-shaped valve that uses linear motion to control the disc. The disc moves perpendicular into the seat or out of it to open and close the valve. Globe valves are used for pipes less than 8 inches. A typical globe valve constitutes of

  • Globular shaped valve body
  • Bonnet
  • Plug or Disc
  • Yoke
  • Stem
  • Seat ring
  • Flange and gland bushing
  • Gland bolts and nuts
  • Yoke sleeve
  • Mechanical actuator
  • Pressure seal gasket
  • Back seat
  • Packing
Blue with yellow colour globe valve installed by Oilway in the outdoor place of industrial unit

Globe valve suppliers in Singapore offer three common types of globe valves for industrial purposes: T-Type, Y-Type, and Angle Type.

  • T-Type Valves – These globe valves are used for systems that require high throttling and where the high-pressure drop is not a concern. It has the lowest flow coefficient.
  • Y-Type Valves – These are commonly used globe valves that have very low flow resistance. They can be kept open for a longer period without causing erosion.
  • Angle Type Valve – These are commonly used in systems that require pulsating flow as they can effortlessly handle the slugging effect. They do not need an elbow to direct the flow in a perpendicular direction.

Also Read : The Gate Valve, Globe Valve and Butterfly Valve

How Does A Globe Valve Work?

Globe valves are mainly used to stop, start or regulate fluid flow. A handwheel fixed on top is used to lower or raise the disc. The handwheel can be operated manually or by using an actuator. When the disk inside the valve body moves up, the valve stem pops out, and the fluid flows through the pipeline proportionally. When the disc seals on the seat ring, the flow is stopped completely. The stem will control the seating load of the disc. Globe valves either have a soft seat or metal seat. It comes in several seats and disc design variations to have uniform seating stress. Conventional disc, composition disc and plug discs are three main disc designs for globe valves.

  • Conventional disc – Also called a ball disc, in this type, the disc and seat structure is ball-shaped and has a short taper that fits against the flat seat. It is an economical and popular design used in low-pressure systems.
  • Composition Disk – In this design, a non-metallic, hard insert ring is placed on the disk for tight sealing. It offers high corrosion resistance and resilience and hence used in high pressure and temperature applications. A composition disc can be repaired or replaced.
  • Plug Disk – It is one of the best disc designs among the three and is most used in throttling systems. The plug disc is made of a long tapered metal plug that fits into the seat like a cone generation a wide surface.

For systems that operate under low temperature, the flow direction is installed to make the pressure act under the disk. This design eliminates erosion to the disc dace and seat. It is also easy to operate and has protective packing. Whereas, in a high-temperature system, the parts are positioned so that the pressure act above the disk. This design will avoid stem contraction undercooling.

Benefits And Applications Globe Valves

Due to the proportional relationship between the disc and the flow, globe valves can be used for different flow regulations. The travel distance of the disc to open and close is short and hence can be used in applications that require frequent on and off. Other benefits of globe valves are:

  • Since the sealing capacity of these valves is high, globe valves offer the best shut off capabilities with low friction.
  • With a slight design change, these valves can easily be used as a stop check valve.
  • It is easy to resurface and machine the seats.
  • Its simple structure and smaller operations provide shorter closing and opening times.
  • It has a throttling capability that ranges from moderate to good.

Some of the applications of globe valves are –

  • Well-regulated cooling water systems
  • Fuel oil systems
  • High-point vents
  • Low-point drains
  • Extraction drain systems
  • Feed water
  • Chemical feed
  • Condenser air extraction
  • Turbine drains/seals
  • Turbine lube oils systems
  • Heater drains
  • Main steam vents and drains
  • Boiler vents and drains

At Oilway, the leading industrial valve manufacturers in Singapore, we ensure high commitment and dedication to provide consistent and high-quality globe valves. Call us, and we will be happy to help.