Valves, Actuators & Pump Control


Arca anti-surge valves for Sasol compressors

September 2015 Valves, Actuators & Pump Control

Arca rounds off its proven series of Ecotrol control valves at the high end with the introduction of the nominal size DN 700 (28”). This valve has been specially optimised for use as an anti-surge valve on turbo compressors, but can also be used for all control applications involving liquid and gaseous media.

The requirement profile for the new development was:

• High flow coefficient Kvs, which usually well exceeds the delivery capacity of the turbo compressor. The quantities of gas trapped inside the pipelines and heat exchangers can therefore also be relaxed in a very short space of time upon safety shutdown of the compressor.

• Face to face dimension according to the specifications of EN 558.

• Mechanical resistance to the energy converted at the anti-surge valve and to mechanical forces due to pressure fluctuations or unfavourable pipeline layouts.

• Favourable acoustic characteristic values.

• Short actuating times, usually considerably less than two seconds for the complete 0 – 100% valve cycle.

The overall length in accordance with EN 558 represents a particular constructive challenge in the case of globe style control valves, especially with large nominal sizes, since the ratio of seat diameter (ideally the same as the nominal size of the valve) to the overall length becomes increasingly unfavourable the larger the nominal size becomes. For this reason the parametric modelling technique using an upfront CAE tool was applied for the first time for the fluidic optimisation of the housing shape.

In this development process the component to be developed is defined (apart from fixed boundary conditions such as the process connections, the wall thicknesses and the trim) by a variable, parameter-controlled geometry. Beyond that, with reference to the target market as an anti-surge valve, the relaxation of an ideal gas with a pressure ratio x = (p1-p2)/p1 = 0.7) and the flow direction ‘flow to open’ were specified. In constant alternation between variation of the geometry and evaluation of the results (in the case of the valve housing the flow coefficient determined by means of CFD), the system converged after more than 60 variants to an optimum solution with a 25% higher coefficient of flow in comparison with a conventional design.

In combination with the associated spring-return pneumatic piston actuator, which can be operated in both single-action mode and (for significant improvement of the control dynamics while maintaining a defined safety position in case of a failure of signals or power) double-action mode, this valve offers a technically and economically ideal solution in many applications.

For more information contact Fred Venter, Valve & Automation, +27 (0)11 397 2833, [email protected], www.valve.co.za



Credit(s)



Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

Compact valve position indicator
Emerson Automation Solutions Valves, Actuators & Pump Control
Emerson’s new TopWorx DVR Switchbox is an entry-level addition to the DV Series of valve position indicators. It combines a durable resin enclosure, compact size, and a patented cam design that provides a reliable valve position feedback for water and wastewater systems, food and beverage production lines, and industrial utilities.

Read more...
Precision, control and performance in regulators and control valves
Valve & Automation Valves, Actuators & Pump Control
Cashco has long been a trusted name in industrial control solutions, offering a broad range of regulators and control valves designed to meet the rigorous demands of various industries. There are two key Cashco product lines, its regulators and the Ranger QCT control valve.

Read more...
Advanced solutions for valves
Bearing Man Group t/a BMG Valves, Actuators & Pump Control
BMG delivers state-of-the-art valve solutions to diverse industries across Africa, in collaboration with InterApp, a global leader in the design and manufacture of high-quality valves.

Read more...
ENERGYValves expands operations
Valves, Actuators & Pump Control
ENERGYValves is expanding its operations with a new facility in Cape Town. The new premises will significantly enhance the company’s capacity to serve the Cape Town market and surrounding areas.

Read more...
Revolutionising slurry management in mining operations
Valves, Actuators & Pump Control
Dynamic Fluid Control has launched the Vent-O-Mat Slurry Air Release Valve, designed to set new standards in performance and technology for the mining industry.

Read more...
Inspection system for leak detection in valves in hazardous areas
Extech Safety Systems Valves, Actuators & Pump Control
Leaking valves in industrial plants not only lead to loss, safety risks and possible contamination and pollution, but also result in high economic costs. Therefore, valves in hazardous areas require regular proper inspection and preventive maintenance to ensure their functionality.

Read more...
Valve & Automation is exclusive agent for Cashco
Valve & Automation News
Valve specialist, Valve & Automation, supplies total valve and control solutions to key process industries throughout southern Africa. The company has now been appointed as the exclusive agent for US company, Cashco for the supply of control valves, regulators, tank equipment and flame arrestors.

Read more...
High-flow solenoid valve
Emerson Automation Solutions Valves, Actuators & Pump Control
Emerson has introduced the new ASCO Series 327C solenoid valve, which features a direct-acting, high-flow design that provides superior flow-to-power ratio. It permits high flows at minimum power levels, making it ideal for use in power plants, refineries, and chemical processing facilities.

Read more...
New system improves performance of magnetic drive pumps
Valves, Actuators & Pump Control
KSB Pumps and Valves has introduced its ground-breaking MagnoProtect system for the local petrochemical, chemical and general industry markets ,to enhance the safety and performance of its magnetic drive pumps.

Read more...
Emerson software optimises maintenance
Emerson Automation Solutions Valves, Actuators & Pump Control
Emerson has announced the Plantweb Insight Valve Health Application, a powerful software tool that combines Fisher control valve expertise with advanced analytic algorithms. The new app makes it possible for users to visualise an entire connected fleet of valves, while prioritising actions based on the health index of each valve.

Read more...