TPi November 2018

Valves & fittings

Explosion-proof variable speed actuators Electric actuator manufacturer Auma has launched explosion-proof variable speed valve actuators for use in potentially hazardous environments.

The new SAVEx actuators for open-close duty and SARVEx multi-turn actuators for modulating duty, combined with intelligent ACVEx actuator controls, provide full control of the motor speed at any time. Variable speed offers advantages for challenging valve control tasks, since it allows the optimum operating speed to be selected for each change of valve position. High positioning accuracy and optimised setpoint control increase the effectiveness of pressure control valves in gas pipelines, for example. On multiport valves, variable speed actuators aid rapid and accurate switch- over between ports. Mechanical stresses on valve, actuator and pipeline are minimised by reducing the operating speed close to the end positions, allowing the moving element of the valve to make gentle contact with the seat. Pressure surges and cavitation effects in the pipeline can be avoided by using speed profiles. When working in modulating duty, the actuator speed can be set to reduce progressively as the valve position

Auma’s new SAVEx and SARVEx variable speed actuators combine accurate setpoint control with mechanically gentle valve operation

and SARVEx actuators complement the weatherproof SAV and SARV range. They are available in six sizes covering torques up to 1,000 Nm. Speed ranges include 6 to 60 rpm, 12 to 108 rpm and 24 to 116 rpm. Auma Actuators Ltd – UK mail@auma.co.uk www.auma.com

approaches the setpoint, giving an increase in positioning accuracy. Actuator speed can also be controlled by an external signal – either 4-20 mA analogue or 0-100 per cent digital – to take full advantage of additional control variables or algorithms. speed synchronisation between two actuators. Auma’s new explosion-proof SAVEx A further option is

Rubber seated ball valves Val-Matic’s Ener-G ® rubber-seated ball valve is a solution for surge control and energy savings in municipal and industrial water and wastewater applications.

replacement of the seat without removing the valve from the line. When fully open, Val-Matic’s Ener-G ball valve provides 100 per cent flow area equal to the pipe size. The valve’s design and performance have been verified through proof of design and independent flow testing. The valve is available with cylinder, electric motor or manual actuation. Val-Matic Valve & Manufacturing Corp – USA valves@valmatic.com www.valmatic.com Photo: Ener-G rubber-seated ball valve

The Ener-G ball valve’s self-flushing contoured ball design fully complies with AWWA C507. It features the advantages of a standard two-piece design with a fusion bonded epoxy interior and exterior coating and a bidirectional resilient Tri-Loc™ seating system. The Tri-Loc seat retention system provides a low-friction, wear-resistant seat, and allows easy adjustment or

Ener-G rubber-seated ball valve

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November 2018 TUBE PRODUCTS INTERNATIONAL