Saunders diaphragm valves and slurry knife gate (SKG) valves continue to sell steadily into mines across Central and Southern Africa, reports valve manufacturer Dynamic Fluid Control Mining (DFC Mining).
Manufactured by DFC Mining at its Sebenza works, Saunders valves are used in a wide variety of corrosive, abrasive and combined corrosive/abrasive fluids, whereas SKG valves are used in specific applications in mine tailings, backfill, thickeners and fly-ash environments, the company states.
DFC Mining claims that its SKG valves do not have pockets that may trap abrasive particles and cause valve damage and a shortened life span.
These valves have been designed to eliminate the bonnets and stuffing boxes associated with traditional designs, and incorporate full-port, heavy-duty elastomer double sleeves to deliver a smooth and uninterrupted full-bore flow.
The SKG valve is a DFC Mining design, whereas the Saunders diaphragm valve is manufactured under licence.
The wide choice of materials for Saunders valves, the methods of operation and body-end connections satisfy the needs of most applications, while their simple design results in low maintenance for minimum running costs, the company believes.
On both pressure and vacuum, Saunders valves operate and close without any leakage.
The valves may be operated by a handwheel, or by fast-acting levers, pneumatic and electric actuators, and there is positive visual identification of operating status, that is open or closed.
Saunders valve stems are designed to reduce friction for low-operating torque. Sealing operating mechanisms are isolated from service and atmosphere, avoiding the need for exotic metals. A fully sealed option is available for corrosive applications.
Strong and resilient diaphragm valves give positive shutoff, assisting flow and completely isolating working parts from the line fluids, states the company.
DFC Mining explains that body-end connections are available in screwed, flanged and weld-end options to suit UK, European, US specifications and avoid planning problems.