¿Cómo funciona una válvula de globo? Una explicación completa

Globe valves are one of the most versatile types of valves used to regulate fluid flow in piping systems. But how exactly does a válvula de globo work? In this complete guide, we’ll dive into the mechanics behind globe valves, the components that allow them to smoothly control media flow, common designs and materials, and typical applications.

How Globe Valves Operate to Control Flow

At a high level, cómo funciona una válvula de globo comes down to the linear movement of an internal disk or plug in relation to a stationary seat ring in the valve body. As the plug lifts up off the seat, it opens a flow path, allowing media to travel through the valve. As the plug lowers back into the seat, it gradually cuts off flow until it forms a complete seal.

This gives globe valves precise throttling capability to finely tune flow rates. The key operating components enabling this smooth control are:

Stem and Actuator

The valve plug connects to a stem that transfers linear movement to open and close the flow path. The stem may be manual with a handwheel actuator. Or automated using pneumatics, hydraulics or electric power. The actuator provides precise control to lift and lower the plug.

Plug and Seat

The plug is the moveable flow control element with a tapered surface that seals against the stationary ring seat when fully closed. As the plug lifts off the seat, an annular opening is created to allow flow. Different plug shapes and seat designs enable customized flow performance.

Body and Bonnet

The pressurized sections of the valve featuring the flow path components. The body houses the plug and seat, while the bonnet seals the stem. Standard bolted bonnet construction allows fast maintenance access to internal trim parts.

As the actuator raises and lowers the plug inside the valve, you can precisely dial flow from fully closed to fully open. Next we’ll explore some common globe valve variations and materials suited for specialized applications.

Globe Valve Styles, Materials and Uses

While all globe valves work on the same fundamental concept, the exact construction can vary significantly based on required function and performance specifications:

Standard Globe Valves

The most ubiquitous style with Z-shaped flow path changing direction twice. Enables accurate throttling control with good shutoff capability. Used for flow regulation in general industrial processes.

Angle Globe Valves

Inlet and outlet at 90 degrees resembling an elbow. Single change in direction reduces turbulence for lower pressure drop than standard globe valves. Useful where piping layout requires both flow control and direction change.

Y-Pattern Globe Valves

Angled construction provides more direct flow path than standard globe for lower resistance and minimal pressure loss. Low flow restriction makes Y-pattern globe valves suitable for throttling tasks.

Double Seated Globe Valves

Featuring two plugs with individual actuator stems for balanced operation. Accommodates bi-directional flow and minimizes actuation force requirements. Used in high flow water treatment systems.

In terms of materials, globe valves handles a wide range of fluids from cryogenics up to extremely high temperatures beyond normal steel limits:

• Bronze globe valves for non-corrosive water and steam flows
• Brass valves for hot water circulation heating systems
• Cast iron globe valves offer durability for cold and hot water flows
• Stainless steel valves for corrosive chemicals and high temp oil/gas media
• Exotic alloys like Hastelloy handle molten glass, acids, radioactive substances

This combination of configurable construction and extensive material compatibility makes globe valves a tremendously versatile flow control element suitable for processes across all industries.

Conclusión

We’ve just explored the internal functioning, designs, and specialized materials enabling cómo funciona una válvula de globo to smoothly modulate flow in piping systems. The movable tapered plug provides precise throttling capability as it lifts on and off the stationary ring seat in response to stem and actuator movement. Configuring the flow path components and global valve alloy suited for specific media ensures optimal performance and longevity.

Globe valves handle everything from steam, oils, fuels and chemicals to cryogenics and molten metals, making them an indispensible flow control element for industrial process piping across all sectors. Their exceptional versatility with relatively straightforward internal mechanisms makes globe valves a wise choice for accurate, reliable fluid control.