Valve actuators are often misconceived as relatively simple devices that perform a straightforward function. There are, however, significant opportunities and substantial savings available to the control engineer through the smart deployment of actuator technologies.

There are two distinct functions that a valve actuator performs – the ‘intelligence’ of managing digital or analogue control signals and feedback loops, and the ‘brute force’ to open and close a variety of different valve types. At AUMA we separate the ‘intelligence’ and ‘brute force’ by taking a modular approach to our actuator construction. This provides an enhanced choice of actuator configuration for our customers, dependent on the end application.

Analogue or digital control heads or, indeed, no control head, can be connected to a range of different drive units through AUMA’s common interface. The symmetrical connection design enables the head to be connected in one of four different orientations. In addition, the basic actuator can be built on site in up to 64 different configurations. The control head can also be connected through an umbilical cable of up to 100m length, so the two components can be separated for safety or operational convenience, for example in underground or underwater applications.

Sophisticated Control

While fixed speed open/close functionality satisfies the majority of valve actuation situations, there are opportunities available from more sophisticated variable speed actuators. Water hammer can be a significant issue in many applications. Valve seats suffer if they are driven hard to their end positions whenever the valve is closed. A variable speed actuator, such as the AUMA SIPOS SEVEN, gives the control engineer the opportunity to specify the speed of actuation at different points in the cycle. The usual way that this is employed is to move the valve quickly through the majority of its cycle, slowing it down as it nears the close position, alleviating water hammer problems and extending the life of the valve seat. For emergency situations a ‘fast close’ speed can be specified.

AUMA’s SIPOS SEVEN also has a multiple speed/set point capability. This can be used to provide near linear performance from low cost non-linear valves. A further interesting benefit of a variable speed system with a clever built-in inverter, like SIPOS SEVEN, is that it provides high start-up torque without peak start-up current and low overall power. What that means in practice is that cables, even on long runs, can be specified for the nominal currents and remote, even solar powered applications become possible.

Reducing system costs at Control Design stage

The valve actuator, in almost all cases, arrives on site as part of the valve package, and may only be considered as a means to an end. However, the actuator should also be considered as part of the site control system. Other sensors within the process, such as level or flow monitors, can make use of the actuator’s in-built A/D conversion and industrial Ethernet connectivity to feed data back to the central control system. AUMA’s AC .2 actuator controls optionally include PROFINET for transfer rates up to 100Mbit/s, with simplified commissioning through automatic address assignment.

The modular approach also provides another interesting time and cost-saving opportunity. There is no need, technically, for the entire actuator to be supplied to the valve manufacturer or directly to site. It is perfectly feasible for the valve supplier to receive the mechanical components, the gear box etc (what AUMA refer to as the ‘Norm’), while the control engineers take delivery of the control unit. That way, configuration and programming can be undertaken before the two parts of the actuator are reunited on site. Valve assemblies can be delivered on skids and installation work on site is significantly reduced. 

AUMA has supported these new opportunities with a multi-level training programme, ACE, which certificates technicians and engineers based within valve manufacturers, systems integrators or on-site, at the level appropriate to their task – Level 1 for correct installation and configuration, typically at the valve supplier, and Levels 2 and 3 covering more detail, including commissioning, configuration and system integration.

What do a fox and an electric valve actuator have in common? A lot, if the actuator in question is AUMA’s brand-new PROFOX. Like its namesake, PROFOX is not only cunning and adaptable but also extremely hardy. AUMA’s more than 50 years of experience developing and manufacturing electric actuators has yielded a high-performance actuator series with exciting new features and an excellent cost-benefit ratio. Aimed at applications requiring fast and precise positioning, utmost flexibility and future-proof interfaces, the smart and compact PROFOX series is suitable for all industry sectors, including water treatment, combined heat and power plants, process industries, and shipbuilding.

Cunning. Built-in intelligence makes PROFOX equally suited to both simple open-close duty and challenging modulating applications. Motor speed is adjustable, ensuring fast and precise positioning without overrun. Soft start and soft stop functionality increases valve lifetime. Operating costs are low, thanks to high mechanical efficiency and low standby consumption. Innovative diagnostics ensure long-term availability and future-proof PROFOX actuators for IIoT applications.

Adaptable. AUMA PROFOX actuators work with gate, butterfly, ball and globe valves. There are multi-turn versions for torques of 10 – 100 Nm and part-turn versions delivering 32 – 600 Nm. A linear actuator will follow soon. Modular design ensures flexible configuration, rapid delivery and consistent operation. Host system integration is equally flexible; PROFOX actuators support the most common communication protocols and are well prepared for future evolutions. Compact design allows PROFOX actuators to fit tight spaces.

Hardy. The PROFOX series is engineered and built in Germany – and designed to last, even under the toughest process conditions. High-quality metal housing with IP67 protection (IP68 optional) and AUMA’s unique corrosion protection, which meets the highest C5-M/C5-I requirements of EN ISO 12944-6, ensure that PROFOX actuators have a long life at temperatures from –30 °C to +70 °C.

PROFOX actuators are simple and easy to use. Installation and commissioning are fast and convenient, using either the integral pushbuttons or an intuitive app. The FOX-EYE indicator light and a position indicator on the housing clearly show the actuator status at any time, even from a distance.

 “The new PROFOX actuator series is set to lead the market thanks to its unique combination of features,” says AUMA product manager Christoph Edelmann. “It offers unprecedented intelligence, precision, efficiency and flexibility at a very attractive price.”

www.profox.auma.com

AUMA has launched its new SIMA² Master Station, providing high-performance actuator control and supervision via open fieldbus standards. By optimising communications between field devices and host system, the SIMA² Master Station simplifies all aspects of configuring, controlling and managing actuators and other field devices over the plant’s life cycle. While suitable for any type or size of plant, across all industry sectors, SIMA² Master Station is particularly beneficial for extensive sites with large numbers of actuators, such as tank farms and refineries.

One SIMA² Master Station can manage up to 988 actuators in four independent networks, arranged as loop or line topologies. Total cable length without external repeaters can be up to 296 km per network.

SIMA² exclusively uses standardised, proven fieldbus protocols to ensure high-speed and reliable communication as well as long-term security of investment. The system supports Modbus RTU and Modbus TCP/IP to communicate with the host, linking to the actuators via either Modbus RTU or Profibus DP. Cycle times are extremely short, enhancing process efficiency.

Integral Ethernet and OPC UA interfaces facilitate data exchange, ensuring future-proofing for IIoT applications.

Multiple redundancy options maximise plant availability. Modbus RTU loop topology with built-in redundancy ensures communication even in the event of a cable break, for instance, while hot-standby architecture provides redundancy at system level.

Communication parameters can be easily set, and fieldbus networks configured, commissioned and tested, directly from the SIMA² Master Station, speeding up commissioning. During normal plant operation, SIMA² coordinates all actuator commands and feedback signals, reducing host communications to an absolute minimum. Comprehensive diagnostic functions facilitate fault-finding and asset management.

Operating the SIMA² Master Station is intuitive and convenient, whether using the large integral multi-touchscreen or an external web browser. The compact and ergonomic design of the SIMA² Master Station minimises installation time and cost. Housing options include 19-inch rack mounting or turnkey solutions, within a control cabinet or for outdoor installation.

“Our new high-performance Master Station strengthens AUMA’s position especially on the oil and gas market”, says Sascha Loth, Product Manager at AUMA. “We have already supplied SIMA² to numerous reference projects worldwide, and it really is proving its performance. Our customers are enthusiastic about its ease of use and its extremely reliable and high-speed communication.”

To read more, click here for the product page on www.auma.com

AUMA offers a new high precision automation solution for multiport valves based on SAVEx electric actuators with adjustable motor speed. The actuators support up to 16 ports with a combination of short operating times and excellent precision, thanks to their variable speed motors. Positioning accuracy is better than 0.3°, making the actuators suitable for the most challenging applications in this market. Switch valves with lift plug design are also supported.

Multiport valves find application in the oil and gas industry in sampling systems for multiple wellheads. Fluids from each well in turn can be directed to a single sampling system, allowing operators to monitor current production in detail. The positioning accuracy required makes this a challenging application for actuators.

AUMA’s SAVEx variable-speed actuators are ideal for this task. For rapid switching, the actuator motor runs at high speed over most of its travel. Just before the valve plug reaches the target port position, however, the speed is considerably reduced. By virtually eliminating overrun, this allows extremely precise positioning.

Switch valves with lift plug design require an even more demanding actuation solution since two different movements have to be coordinated: before the plug can rotate to the desired outlet it has to be lifted from its seat. This requires a second actuator. AUMA’s clever and simple solution is to use two actuators in a master-slave configuration that appears to the DCS as a single actuator. The intelligent actuator controls handle the complete sequence of movements and the safety interlock.

AUMA has also expanded its list of communication protocols supporting multiport and switch valve functionality: Foundation Fieldbus is now also available, in addition to Profibus DP, Modbus RTU and Modbus TCP/IP

AUMA offers a new sensor system for signalling valve end positions which can be mounted to the company’s GS .3 part-turn gearboxes. The new solution allows plant operators to monitor the position of manually operated valves, and hence to collect crucial valve position information from all the valves in their plants – not just from motor-operated valves, which mostly use the integral limit switching within the actuators to signal valve position. 

The new sensor system adds intelligence to valves at a time when collecting and processing data from smart field devices is at the core of a rising number of Industrial Internet of Things (IIoT) applications in process automation.

The sensor system can also be used in combination with electric valve actuators when redundant valve end position feedback is required in addition to the actuator-embedded functionality. 

AUMA’s new sensor system uses inductive sensor elements which ensure contactless monitoring of the end position for 90° part-turn valves. In contrast to mechanical limit switches, AUMA’s electronic sensor system is wear-free and not subject to corrosion. It combines high switching accuracy with robustness.

GS .3 gearboxes can be ordered with the integral sensor system as of now. Thanks to its modular design, the sensor system can also be easily retrofitted to existing GS .3 gearboxes in the field. 

The sensor system is available in two versions: a cost-efficient basic version and a fully-sealed premium version with aluminium housing offering enhanced IP69K protection. The premium version is particularly suitable for outdoor installation. Both versions are also available with ATEX approval for use in potentially explosive atmospheres.