Globe valve, Applications, advantages and disadvantages

Globe valve is a series of linear valves that are used to connect and disconnect, start and regulate fluid flow. In this article, we will examine the structure of Globe valve, its use, advantages and disadvantages.

A disk is considered in the structure of Globe valve. The disc can completely move out of the fluid passageway or completely block the fluid passageway.

The globe valve can also be used for isolation or evacuation.

Globe Valves have a different structure than ball valves. Compared to gate valves, plug valves, ball valves, globe valves create a higher pressure drop in the fluid. In cases where the pressure drop in the fluid is not a determining factor, globe valves can be used.

All the applied pressure is transferred to the valve disc, then to the valve shaft. Therefore, we have limitations in the design of this valve model. According to the mentioned cases, the size of the valve can finally be (NPS 12 (DN 300). Faucets and valves with large sizes are usually exceptions.

If the valves are not designed in the specified size, we need a huge force to open and close the valve.

Globe valves up to NPS 48 (DN 1200) sizes have been designed and installed.

Globe valves are widely used for flow control. To ensure valve performance, flow control range, pressure drop and valve performance should be considered.

The applied pressure difference should not be higher than 20% of the maximum working pressure of the valve.

Globe valve body design

Globe valves are designed and manufactured in one of the following three models:

Tee Pattern or Z-body

 Angle Pattern

 Wye Pattern or Y-body body

TEE PATTERN GLOBE VALVE

The most common globe valve model in the industry is T-shaped. The horizontal setting of the site allows the rod to be placed vertically on the disc in line with the horizon line.

This design model has the lowest flow coefficient and higher pressure drop. We usually use this design model for applications where pressure drop is not important.

ANGLE PATTERN GLOBE VALVES DESIGN

In this model, the outlet valve has a 90 degree angle to the inlet valve and the fluid rotates at a 90 degree angle. This model has a lower coefficient than the previous model. This model is generally used for applications where the fluid flows periodically or pulses through the valve.

Y-shaped globe valve or WYE PATTERN GLOBE VALVES DESIGN

In this model, seat and valve rod make a 45 degree angle together. Therefore, in this model, the flow path is completely straight and causes minimal resistance to the flow. This model can be used for a long period without needing service.

Advantages and disadvantages of globe valve

Advantages
  • Good ability to disconnect and connect fluid flow
  • High ability to maintain fluid flow
  • Higher connection and disconnection speed compared to gate valve
  • Design in three different models
  • Easy site settings and maintenance
  • It is used as a check valve if the disc is disconnected from the rod.
Disadvantages
  • High pressure drop
  • High force and high drive to change the position of the valve

Common uses of  Globe valves

In the following, you can see some of the common uses of Globe valves

  • In cooling systems where we need to adjust the flow.
  • Oil fuel system that needs to regulate fluid flow and leakage.
  • In the applications of discharge from above and discharge from the bottom point, where safety and fluid leakage are of great importance.
  • Food, chemical, air extraction and exhaust systems
  • Boiler valves and outlets, steam valves, turbine and drain valves

In pumps, valves that have the same internal mechanism are known as stop valves. The internal structure of this valve model may not be spherical.

Globe valve is used in chemical and petrochemical industries, refineries and food and pharmaceutical industries.