Improved commodity prices have resulted in increased demand for knife gate valves from slurry-related valves manufacturer Abrasive Flow Solutions (AFS), in Gauteng, as mining houses upgrade existing facilities and proceed with previously unfeasible projects.

“The rand:dollar exchange rate has also improved demand from the mining, power, water and food industries, while the continuous upgrading of bulk water supply remains a priority in Africa,” says AFS GM Donald Morrison.

Established by engineering consumables and components manufacturer Engineering Solutions Group (ESG) of investment holding and management company Invicta Holdings to expand its fluid technology services in Africa, AFS celebrated its first year of business recently in March.

A Level 2 broad-based black economic-empowerment company, AFS has and continues to enhance the design of its slurry knife gate valve range, focusing on the working relationship between the sleeve and the gate.

“We believe that our sleeve is designed to operate efficiently while still retaining memory for effective sealing between the gate and sleeve, thereby offering a longer operating life and, ultimately, a cost saving to the end-user,” says Morrison, adding that over the last year AFS has established a new rubber lining facility, with the installation of autoclaves that have capacities of up to 10 m in length. The company has also made a significant investment to extend its hydraulic pressing facility.

Production of its knife gate valves has also been simplified by leveraging the expertise of companies within ESG, which range from metal casting to machining.

AFS introduced its knife gate valve range over the past year in response to the numerous requests from the public and private sectors for the supply of locally produced knife gate valves that can handle higher pressures, such as 50 bar, or have an American National Standards Institute flange pressure rating of 300.

The range includes flanged, wafer, lugged, urethane-lined and high-pressure knife gate valves from 50 mm to 1.8 m in diameter.

Morrison confirms that orders for AFS’s knife gate valves have been received and supplied this year, with many tenders to be finalised in the coming months.

All the company’s valves are produced and tested at its facilities in Apex, Benoni, where about 40 people are involved in the manufacturing process of its gate valves. Most of the supplied parts and machining are outsourced and manufactured or machined according to AFS’s drawings. 

Before manufacturing starts, the company confirms that its customers are procuring the correct valve for their specific application. Once determined, AFS provides a general arrangement drawing to confirm which product will be supplied.

“We then procure the parts or pull from stock. Bodies are cast at the foundry then machined and drilled according to customer specifications. Parts are then laser cut and fabricated where needed. All parts are painted and assembled, following which valves are tested according to the designed pressure,” explains Morrison.

The quantity of valves produced by AFS varies according to their size, which ranges from 50 mm to 1 800 mm.

The company’s knife gate valves are exported into the rest of Africa and to the Middle East, Australasia and the Americas, with the South American mining sector being a large user, concludes Morrison.