Basic Guide About Globe Valves

General

Any check valves or globe valves look almost similar from the outside however they operate quite differently. Globe valves are always widely known among users as a standard industrial device for throttling and controlling of fluids.

In this small write up we will discuss about various design variations of globe valves, best applications, advantages and disadvantages.  

What is globe valve?

Any globe valve will be comprised of 2 portions separated by certain amount of opening with moveable disc or plug that is screwed in or can also be unscrewed for opening and closing. Baumann valves are most commonly used for opening, closing, or throttling flow in the system.

All kinds of globe valves usually are designed with any stem that will move up and down for regulating the flow inside the valve and contains a disc made of ball or plug, which is normally screwed into the valve body. The seats are usually designed in parallel or inclined plane to the flow line.

There are 3 basic body designs of globe valve:

  • Angle
  • Tee
  • Wye.

Angle

Ends of such valve are at an angle of 90° letting the fluid to flow within a 90° turn. This kind of valve is normally used for such applications where there are intervals of pulsating flow, due to their ability of handling “the slugging effect” that naturally occurs along with pulsating flow.

Tee

This is one of the most common variety of globe valves. Its horizontal setting of seat will allow stem and disk for travelling perpendicular to horizontal line. Such kind of design has minimum coefficient of flow with maximum pressure drop.

They are normally used in the severe throttling services, e.g. in the bypass lines around any control valve. Wherever the pressure drop is really not a concern also throttling is needed, this kind of globe valve design can be a good solution.

Wye

This is another alternative for any high pressure drop that is commonly found in any globe valves. Its stem and seat are at 45° angle that provides a straighter flow path, when it is fully open and also offers minimum resistance of flow. Such design is usually used to throttle during start-up or seasonal operations.

Best applications

Globe valves can be beneficial for different applications where the flow should be regulated and always constant fluid flow is not necessarily needed. Following are few applications where any globe valve can be used:

  • Boiler or main steam drains and vents
  • Cooling water systems
  • Feedwater or any chemical feed system
  • Fuel oil systems
  • System for turbine lube oil and others

Advantages

  • As stop-check valve, in case the disc and stem are not attached
  • Easier to maintain and also resurface the seats
  • These globe valves have got both shutoff capabilities and good throttling

Disadvantages

  • High pressure drops
  • Requires a larger actuator or greater force for seating the valve

If you are facing any issues with this globe valve, or in case you need to choose any new one for the process then discuss with an engineer who is experienced in selecting and sizing of these kinds of valves.

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