Globe valves: what they are and how they work

Comprehensive guide to the characteristics, operation and different application possibilities of globe valves

Globe valves are control valves essential for the flow control of fluids in a wide range of applications. Due to their structure, characterized by a shutter that moves perpendicular to the valve seat, they allow precise flow control and are therefore ideal for all cases where the flow of liquids or gasses needs to be precisely regulated. The applications of globe valves are manifold: from the oil and gas industry, where they are used to manage the flow of hydrocarbons even under critical operating conditions, to the chemical sector and to heating and hydraulic systems, where they are used to precisely regulate the inflow of hot and cold water.

 

Choosing the right globe valve for each specific application is crucial to ensure maximum efficiency and longevity of systems. The selection depends on various factors, including the type of fluid, temperature, working pressure and chemical characteristics of the environment. Using a globe valve constructed of inappropriate materials or with improper characteristics can lead to high leakage, malfunction and maintenance costs. Therefore, a careful assessment of technical specifications and operating conditions is essential to ensure safe and efficient operation. 

 

Let’s see what globe valves are, how they work and some useful tips to choose the most suitable types for each application. 

What is a globe valve?

 

A globe valve is a linear motion shut-off valve designed to regulate or stop the flow of fluids within a piping system. Its name comes from the spherical shape of the body ("globe") that characterizes it. 
Globe valves have a movable gate, usually in the form of a disc or plug, which moves perpendicular to the flow direction, controlling the opening or closing of the passage. The movement is regulated by a threaded rod, operated manually or by an actuator, which runs through a sealing bushing to ensure system integrity.

 

The structure of a globe valve is composed of several key elements: the body, usually made of cast iron, bronze or special alloys, houses the other components and determines the maximum operating pressure and temperature. The seat, precisely machined inside the body, accommodates the shutter when the valve is closed, ensuring tightness. The shutter, in turn, can be of different types, such as flat disc, conical disc, plug or ball, depending on the specific application and the degree of adjustment desired. The rod, connected to the shutter, transmits the movement from the handwheel or actuator, while the filler ensures the sealing around the rod, preventing fluid leakage.

 

Globe valves are appreciated for their ability to modulate flow precisely and gradually, and are commonly used for control applications. They also offer good tightness and are relatively easy to maintain. However, due to their internal structure, they generate a greater pressure loss than other types of valves, such as gate valves. 

 

Operation of globe valves

 

The operation of globe valves is based on a simple but effective principle: the modulation of the flow through the linear movement of a shutter within a specially shaped seat. In the closed position, the shutter is perfectly placed on the seat, blocking the passage of fluid. When you start to open the valve, the shutter lifts off the seat, creating an opening through which fluid can flow.
The special feature of this type of valve is the shape of the seat and the shutter, which can vary depending on the specific adjustment needs. For example, a flat seat and flat disc shutter provide linear flow regulation, while a conical seat and plug shutter allow finer and more precise adjustment.

 

The movement of the shutter is controlled by a threaded rod, operated manually via a handwheel or automatically by an actuator. The rotation of the stem determines the advance or retreat of the shutter, thus modulating the valve opening and, consequently, the flow rate of the fluid.
Globe valves can cause a pressure drop in the system due to their internal structure and the tortuous path that the fluid must follow. However, this is offset by their excellent control capabilities and reliability even under heavy operating conditions.

 

The main types of globe valves

 

There are different types of globe valves, designed to meet the specific needs of various industrial sectors. Each type has its own characteristics that make it suitable for certain applications and operating conditions. The main types include: 

• straight flow globe valves (or T-type): in this type of valve, the fluid inlet and outlet are aligned along the same axis, forming a "T". This arrangement offers a lower pressure drop than other types, making it suitable for clean fluids and low speeds. However, maintenance may be more complex due to the need to remove the entire valve from the pipe to access the shutter; 
• angular flow (or Y-shaped) globe valves: in this variant, the fluid inlet and outlet form an angle of 90 degrees, creating a "Y". This geometry promotes smoother flow and reduces shutter wear, making it ideal for dirty fluids or with suspended solid particles. In addition, access to the maintenance shutter is facilitated by the ability to remove only the top cover. 

Main applications of globe valves 

 

Due to their versatility and precise adjustment capability, globe valves are used in a wide range of applications. Their robustness and reliability make them essential components in all systems and plants that require accurate control of fluid flow, including:  

• boilers and steam systems: in these high temperature and pressure environments, globe valves demonstrate their reliability in managing the flow of steam. They regulate the steam flow rate to optimize energy efficiency, stop supply when necessary and maintain pressure within safe limits, preventing overpressures and ensuring plant integrity; 
• water and water treatment plants: the precision of chemical dosing is crucial for the proper functioning of these plants. Thanks to their fine flow modulation, globe valves allow for accurate dosing of reagents, guaranteeing the quality of the treated water and the efficiency of the purification processes. In addition, their leak-tightness prevents chemical leaks, protecting the environment and operator safety; 
• oil and gas industry: In this sector, globe valves can find many applications, from regulating the flow of oil and gas to managing pressure in pipelines. Their robustness and corrosion resistance make them suitable for use in harsh environments, characterized by aggressive fluids and extreme operating conditions. In addition, their insulation capacity allows to intervene on specific sections of the plant without interrupting the entire production process; 
• heating, ventilation and air conditioning systems: by controlling the flow of water or other cooling fluids, globe valves help to maintain a constant temperature and an adequate level of humidity in the rooms. Their precise adjustment capability allows you to optimize energy consumption, reducing operating costs and environmental impact.

 

ECI globe valves: versatile and high-strength products for various applications and industries

 

ECI globe valves are versatile and reliable solutions for a wide range of industrial applications. Thanks to their robust construction and the use of high-quality, high-strength materials, ECI valves guarantee a long service life and high wear resistance, even under demanding operating conditions. Available in different sizes and configurations, they are designed to withstand different operating pressures and can be easily adapted to the specific needs of each plant. In addition, their compatibility with a variety of fluids including water, oil, air and steam makes them particularly versatile and ideal for meeting different application needs.  

 

Flanged globe valves are available, such as the G 401 valve, designed and manufactured in accordance with the MSS SP-85 standard, which offers excellent performance in terms of sealing, resistance and durability.
Made of cast iron, a material known for its strength and corrosion resistance can be used with a wide range of fluids including water, oil, air and steam. Its external screw configuration (OS&Y) ensures an immediate visual indication of the valve opening or closing state, facilitating control and maintenance operations. The G403 globe valve is equipped with a perforated flange in accordance with BS EN 1092-2 PN16, ensuring perfect compatibility with standard piping systems.

 

For more information on ECI globe valves, please contact us!