Válvulas de globo
Las válvulas de globo de Fisher ofrecen una amplia versatilidad del proceso y resuelven las necesidades de aplicaciones, desde grandes hasta pequeñas, de calientes a frías y de generales a severas.
Las válvulas de globo de Fisher ofrecen una amplia versatilidad del proceso y resuelven las necesidades de aplicaciones, desde grandes hasta pequeñas, de calientes a frías y de generales a severas.
Una válvula de globo de regulación utiliza un movimiento lineal para mover un elemento de cierre hacia dentro y fuera de una superficie de asiento. Tienen un cuerpo que se distingue por una cavidad en forma globular alrededor de la región del puerto y están diseñadas para regular el flujo del proceso cuando se usa junto a un ensamble del actuador. Muchos de los cuerpos de válvulas de un asiento usan la construcción del estilo de retén o jaula para retener el anillo de asiento, proporcionar una guía del tapón de la válvula y proporcionar un medio para establecer las características de flujo específicas de la válvula. Los cuerpos de válvula de asiento individual del estilo de retén o jaula también se pueden modificar fácilmente al cambiar las partes de los internos para cambiar la característica de flujo o proporcionar el caudal de capacidad reducida, la atenuación de ruido, o la reducción o eliminación de cavitación.
Globe valves are available in a variety of sizes (NPS 1/2 thru 36) and provide users with high performance and reliability. They can help solve an array of application needs from big to small, hot to cold, general to severe.
Bonnets are available in different styles to accommodate different application temperatures. This primarily includes standard bonnets and optional extension bonnets, which may be used to protect packing materials when the valve is used in extremely hot or cold applications.
There are also special packing configurations for applications that require the packing system to maintain fugitive emission concentrations below environmental standards.
Some of the most typical applications of globe valves include cooling water systems, fuel oil systems, feedwater or chemical feed systems, boiler and main steam vents and drains, and turbine lube oil systems.
Globe valves can be fitted with balanced or unbalanced plug designs. Balanced ports allow for equal process pressure above and below the plug, and typical flow direction is down through the seat ring. An unbalanced plug is solid, with no through holes, and typical flow direction is up through the seat ring.
There are also several ways to guide the plug in a globe valve, most commonly cage-guided and post-guided. Cage-guided assemblies can use both balanced and unbalanced valve plug designs. This guiding method uses the outside diameter of the plug in contact with the inside diameter of the cage and provides very good pug stability and alignment, but requires very tight tolerances between the plug and the cage. Post-guided assemblies replace the cage with a component called a seat ring retainer. The seat ring retainer contains a guide bushing that provides guiding for a post on the plug. This style allows for an open flow path around the plug which makes post-guided trims better for us with viscous and dirty fluids.
A choice of trims with different flow characteristics allow globe valves to be linear, equal percentage, or quick opening so they can meet capacity demands from 0.001 Cv up to 12,000 Cv.
Specialty trims are also available that have been designed to prevent noise and cavitation issues in both clean and dirty applications.
