Valve automation dramatically improves control, precision and efficiency. While these advantages must be weighed against higher capital and operating costs, Limitorque actuators are frequently found to be a cost-effective investment for most oil and gas applications.
Limitorque Electric Actuation
Electric actuators use electrical power to actuate a valve. While most of the basic technology used in electric actuators has been around since the 1930’s, decades of incremental improvement have significantly increased their functionality while dramatically reducing their cost. In recent years, these advances have reached a tipping point that makes electric actuators the first choice for a wide variety of applications.
Pros
- Electric power is relatively inexpensive, easy to manage, and normally available to most industrial sites. The capital cost of electric actuators is typically cheaper per equivalent unit of torque/thrust output. They’re also cleaner and safer to operate.
- Electric actuators can provide superior positioning accuracy for control or modulating valve functions, which can include provisions for a high degree of process monitoring, data logging and information feedback.
- All necessary control functions are integral to electric actuators, reducing capital costs. • Electric actuators significantly reduce control wiring costs by enabling distributed control. They simplify control logic by integrating control commands and feedback into customer SCADA or DCS systems. (Traditional electromechanical control systems require a dedicated wire for each command and feedback signal, leading to cable bundles with seven or more cores as minimum for each actuator. By contrast, a typical bus system can use one twisted pair wire in a daisy chain configuration to carry all required input and output signals.)
- As torque and thrust requirements increase, electric actuators weigh less and have smaller footprints compared to pneumatic actuators. • Electric actuators may be combined with external gearboxes to produce extremely high output thrust and torque values.
Cons
- With the exception of a few specific configurations, electric actuators can’t guarantee a fail-safe stroke but will “fail in the last position.” (Fail-safe stroke refers to an actuator’s ability to move a valve to a predefined safe position when power fails).
- Electric actuators have more complex and sensitive components than the mechanical parts used in other types of actuators. Electronic technology also requires periodic refreshing to keep pace with component changes and improvements.
- Beyond a certain size/torque range, electric actuators are less cost-effective and generally have limitations in operating speed when compared to pneumatic and hydraulic actuators.
- In hazardous areas with potential exposure to explosive process media, electric actuators require more specific certifications and construction features to be considered safe for use. Recommended applications Electric actuation is the first choice for most oil and gas applications. They’re ideal for general process valve automation, non-critical applications, and light-duty modulating applications (generally up to 1200 starts per hour), although some can modulate continuously up to 3600 starts per hour.
The Limitorque product range includes actuators that can be controlled from customers’ motor control centres to electronic actuators that can be remotely controlled field devices. More than 1 million Limitorque actuators have been installed around the world, and some have been in operation for more than 50 years. The ruggedness and reliability of Limitorque electric actuators are among the primary reasons that customers continue to select Limitorque products.
Flowserve Limitorque electric actuators are offered in intrusive and non-intrusive designs, and with numerous optional upgrades to address various process, networking and operational needs.
Actuators requiring 90° of rotation to operate are necessary for quarter-turn valves such as ball, butterfly, plug and dampers, and rotary control valves. These types of Limitorque electric actuators are available for operations such as open-close, modulating, network and rotary service.
Multi-turn actuators are required to operate various types of rising stem valves such as gate, slide-gates, globe, check and linear control valves. These types of Limitorque electric actuators are available for operations such as open-close, modulating, network and linear service.
Jeff Morris Limited The Right Supplier
We offer stock Valves from across the Flowserve Flow Control Range, Worcester, Automax, Limitorque, Atomac, Argus, Durco, Kammer, Valtek and Serck Audco, Along with Mars, Gestra, Warex, Ebro, Hindle and many more.
We’ve been in business for more many years, and over the years, we’ve learned what makes a good product. Dependability, durability and affordability are among our top considerations. Reach out today for more information on our process and product options.
Trust Jeff Morris Limited for your Valves and Pneumatic Actuator Supplies
As one of the most reliable distributors, we’re ready to supply you with the equipment you need from leading manufacturers. In addition, thanks to our outstanding expertise and customer care, the technical support that comes with all our products is unbeatable. Contact us now for product descriptions, selection guidance and more. Tel: +44 (0) 116 2464748 Sales: Sales@jeffmorrislimited.co.uk
