Future aims realised through mining valves product range

9th March 2012 By: Chantelle Kotze

Flow specialist eDart Slurry Valve’s latest control valves range, named the Flash Dart, is a step closer to the company’s aim of becoming a worldwide supplier of slurry flow control systems to the mining industry.

The South African-designed, -analysed and -manufactured control valve with increased durability was released into the mining market last year and is already being supplied overseas and has been successfully installed at local projects.

Owing to a high level of customer loyalty, measured by the amount of repeat orders eDart has received, the company is now focused on providing a complete mining solution for its customers while also improving its delivery time.

eDart hopes to achieve this by improving its systems and by emphasising a sense of urgency at every step of the production process.

As part of system improvements, the company is making its own modifications to its database and interfacing it with eDart’s own graphical user interfaces using enterprise resource planning software created by software development company Syspro.

In future, eDart aims to further grow its mining valves division by extending and improving its analysis division, which focuses on computational fluid dynamics (CFD).

“The CFD software used to develop products allows eDart to perform a number of virtual iterations before any manufacturing takes place. The company is geared towards performing more analysis work in 2012,” says eDart engineer Nicholas Sessions.

“The Flash Dart was successfully installed at a large platinum-producing plant in Rustenburg and has also been supplied to other local mining projects,” he states.

Most of eDart’s products are aimed at the platinum market but are equally effective in coal, gold and uranium operations.

The CFD software, named FloEFD, used in the development of the Flash Dart control valve, allows the valve design to incorporate an underflow into the valve body. This feature enables the heavier, more erosive particles to be passed directly under the seat, which extends the valve life.

The Flash Dart is suited to use in a mill cyclone return stream. However, its replace-able underflow restriction feature, which is fully customisable to its specific application, extends its use to high-flow, coarse-particle, abrasive environments and eDart’s Flash Float – a piece of equipment used in mineral proces-sing to improve processing performance.

Depending on its operating environment, the valve is manufactured in either mild-grade steel with a triple coat of anticorrosive Phenoline paint, or in 304- or 316-grade stainless steel. It is lined with either natural rubber or red gum – a soft but durable Linatex rubber for heavy-duty applications – with sizes between 80 and 400 nominal bore.

“Continuous research and development (R&D) is done on the existing range of eDart slurry control valves to ensure a longer wear life is achieved in abrasive operating environments, such as those in mining applications,” explains Sessions.

R&D has further allowed eDart to rapidly design and develop new niche products in response to market requirements.

One such product is the dual valve con-troller – an electronic component with a microprocessor that was designed to intel-ligently split a control signal. The design and development of this product took three months.

The Poly yDart valve is a mill slurry control valve, which features flow-over the plug – an improvement specifically for longer wear life in extremely abrasive operating environments.

“When a customer wants something specific, we provide a solution,” says Sessions.

The company’s belief in continued edu-cation and training has not only encouraged staff to develop their skills and interests but also opened the door for the development of a skills training programme that comprises two comprehensive courses.

The course named “Savama [the South African Valves and Actuator Manufacturers Association] – Working with Valves” is a good introduction for someone who has had no dealings with valves in the past as well as an important refresher course for anyone who would benefit from the back-to-basics approach to understanding valves.

No specialist knowledge or skills are required – only a technical background is necessary so that there is an understanding of factors such as the difference between pressure and force.

The course is beneficial to anyone who deals with valves, such as mechanical engineers and technicians, maintenance foreman, mechanics and valve salespeople.

The Working with Control Valves course is a more in-depth study and covers such topics as choked flow, control valve sizing, seat leakage, characteristic turndown, multistage high-pressure trims, diffusers, materials, pressure rating, actuator sizing and choice, volume tanks and positioners.

The valve training courses have been offered by eDart for around 30 years now. Depending on the training involved, courses may range from an afternoon to three days or even a correspondence course that takes six months to complete.

“Valves are a fundamental component in a working plant and their importance is often overlooked,” concludes Sessions.