Electronic Valve Actuator Is Designed to Enhance Safety and Reduce Downtime

Jan. 26, 2009
Flowserve introduces the Limitorque QX valve actuator

Flowserve Corporation introduces the Flowserve Limitorque QX valve actuator to its family of electronic actuators.

The Limitorque QX is a quarter-turn, smart electronic valve actuator designed to enhance safety and reduce downtime through improved diagnostics, built-in self-test (BIST) features and LimiGard fault protection capabilities. The Limitorque QX complements the non-intrusive, multi-turn MX actuator by including an absolute encoder, which tracks position without the use of batteries.

The Limitorque QX uses the technology of brushless DC motors, which eliminate sparks, reduces mechanical and electrical noise and dissipates heat better than DC motors with brushes. Unique to the quarter-turn industry, a brushless-actuator design lasts longer than conventional motors and allows for more accurate positioning.

The Limitorque QX is available for optional multi-turn functionality. Designed to thrive in extreme and harsh environments, the actuators are powder-coated in a polyester resin. The actuators are double-sealed, containing any leakage within a separate terminal compartment and include solid-state components for higher reliability and specification.

The Limitorque QX features an easy-to-read LCD screen control panel, which can be rotated 180 degrees. Available in ten languages including English, Spanish, French, Italian, German, Portuguese, Japanese (Katakana), Mandarin, Russian and Malay, the panel supports diagnostic graphs for clear data analysis and collection.

Flowserve Limitorque introduced absolute encoder technology for smart actuators in the Limitorque MX, and continues to lead with its use in the Limitorque QX. An absolute encoder helps simplify valve automation through configuration and setup, normal operations, diagnostics and troubleshooting.

The QX encoder employs system-on-chip technology, which uses a pair of contactless magnets that excite Hall-effect devices and provide redundant, 12-bit resolution over 360 degrees. The implementation of a redundant encoder design means that the device can continue to function reliably even after a number of faults have been accumulated. The redundancy feature is part of the BIST functionality of both the MX and the QX. The BIST feature is incorporated into the controls platform that verifies and validates the reliability of its components, a design that aids companies in meeting the Safety Integrity Level (SIL) requirements of IEC 61508.

The Limitorque QX has LimiGard circuit-protection technology, which continually monitors the motor and control relays, internal logic circuits and external command signals to detect and alarm malfunctions.

The actuator has optional digital components and can operate on a number of networks with different protocols including Foundation Fieldbus, Profibus, DP and Profibus PA, Modbus and Devicenet. This helps the software more easily identify preventative maintenance concerns, reduce downtime and improve operational efficiency.

The Limitorque QX offers Bluetooth wireless connectivity at a range up to 10 meters. When used with Flowserve Limitorque Dashboard Windows-based software, diagnostic information is easily transferred to a Windows Mobile-equipped PDA, laptop computer or mobile phone.