Fisher engineers started with a clean slate in developing the GX control valve. Their goal was to bring unmatched simplicity to control valve ownership. Which meant designing a valve that proves simple to select, apply, operate and maintain. The new Design GX control valve is the result. It embodies all of the design criteria and is claimed to offer the added advantage of being simple to afford.
Simple to apply
The GX product line covers nine sizes between DN 15 and DN 200 (½-inch through 8-inch) to meet a wide range of flow and pipeline sizing requirements. The engineered passages within the GX valve body provide maximum capacity and create a stable flow pattern for smooth operation in each valve size. Actuator selection/sizing is determined automatically by the valve body configuration. No extra engineering is required.
The GX actuator controls up to a 5,1 MPa (740 psi) pressure drop. Its multispring design is field-reversible from spring-open to spring-close action without needing extra parts.
Live-loaded PTFE V-ring stem packing is standard within the GX. The packing system provides superior stem sealing and extended service life. Ultra low friction graphite-based packing and an extension bonnet are available for temperatures above 232°C. A carefully selected line-up of valve body and trim materials means that the GX may be applied to a wide range of applications. Carbon and stainless steels are GX standards along with a choice of several alloys for more corrosive applications. Metal-to-metal seating is also a standard, with options including PTFE soft seating for Class VI shutoff and hardened trim with a Stellite overlay for mildly erosive applications.
Simple to operate
The GX may be used for either throttling or on-off control, with or without a positioner. Digital and analog positioners can be specified, as well as auxiliary solenoids, limit switches and other accessories. These valves are compatible with the IEC 60534-6-1 (Namur) mounting standard.
A typical GX configuration features the Fieldvue DVC2000 series digital valve controller. This industry-leading device brings easier control, enhanced performance and maintenance advantages to control valve applications. Fieldvue instruments provide more than just traditional valve positioning. They are core components of Emerson's PlantWeb digital plant architecture. As such, they present the critical operating information about themselves and the process that enables plant personnel to make better-informed decisions. Fisher reports that its PlantWeb digital plant architecture offers proven improvements in system availability, reduced variability, increased throughput and enhanced product quality.
Simple to maintain
The Design GX is robust and compact. Its design architecture features common parts across all sizes, which reduces spare parts inventory requirements and associated costs. Actuator removal is quick and easy. Remove only four fasteners to gain access to the seat ring.
The new DVC2000 features linkage-less position feedback. There are no touching parts between the controller and valve stem, simplifying controller installation and maximising cycle life. The digital valve controller mounts directly onto the actuator yoke and connects to an air passage in the yoke. In the air-to-open mode the instrument introduces actuator loading pressure through the passage. External tubing to the actuator casing is not required. The one-piece packing follower threads into the bonnet to simplify installation and adjustment of the packing system. The system employs live-loading to compensate for normal wear.
Simple to configure
Valve selection is made simple with the Design GX configurator. Available on CD from Fisher sales contacts, the configurator steps the user through an IEC-based sizing procedure that helps them to decide between body size and port diameter options.
The configurator CD also contains complete product documentation, including technical specifications, pressure and temperature capabilities, dimensions, details on construction options, part numbers and recommended spares plus information on how to install, operate and maintain the various GX - positioner - controller combinations.
Simple to afford
The GX is value-engineered to lower its total cost of ownership. Its reduced product complexity and parts commonalities contribute to reduced purchasing, operations and parts inventory and maintenance costs.
For more information contact Luculle Stols, Alpret Control Specialists, 011 249 6700, [email protected], www.alpret.co.za
| Tel: | +27 11 249 6700 |
| Fax: | +27 11 474 8368 |
| Email: | [email protected] |
| www: | www.acs-autocon.com |
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