Over the years Dual Products has gained a multitude of experience in the design and manufacture of specialized valves for all applications including high pressure and high wear applications, this experience has been developed through decades of manufacturing and valve solutions for the vast and varied requirements of the deep mine watering and surface slurry issues in the Southern African mining environment.
Dual Products design and manufacture their range of valves themselves – and hold TUV ISO 9001:2008 Certification No: 01 100 8280063, in the design, manufacture and supply of valves.
The first DUAL VALVE was manufactured in 1983 and was developed to solve various problems on the slurry discharge pipelines. The valve works as an adjustable check valve on the discharge side of the pump, therefore protecting it against back flow and pressure.
DUAL VALVES (PTY) LTD was formed in 1984 by Gerry van Rensburg and Stephen van Rensburg and the DUAL VALVE achieved a remarkable award of wining the SHELL DESIGN AWARDS and the CHAIRMAN’S AWARD in Excellence in 1985, only one year after the formation of the company.
We are proud to be in business for 26 years and look forward to celebrating our 30th anniversary.
Dual‘s Double Non-Return valve (DDNRV) operates on the discharge side of two pumps in parallel. Both pumps can run simultaneously or independently. When one pump is switched off, the ball will automatically drop back stopping the back flow to the other pump. >>more
DUAL‘s Dashley valve (DDV) operates on the discharge side of two pumps in parallel. Both pumps can run simultaneously or independently. When both or one pump is switched off, the ball will automatically drop back stopping the back flow to the pump. >>more
DUAL‘s Free Flow Valve (DFFV) operates on the discharge side of the pump as the flow through the pipeline starts or stops, the ball automatically rises or falls, opening and closing the valve. This occurs without noticeable shock or hammer, regardless of the line pressure or the speed of closure. >>more
DUAL‘s Slimline Valve’s (DSFFV) heart is a reinforced urethane or rubber ball. The unique design of the valve allows free movement of the ball. The ball lifts completely out of the flow when the pump starts and allows free flow of liquid without any interference. As the pump stops, the ball falls and positively locates in the seat due to its own weight and back pressure of the liquid. This results in dropless sealing. >>more
The DUAL valve (DFV) operates on the discharge side of the pump. As the flow through the pipeline starts or stops, the ball automatically rises or falls, opening or closing the valve. The handwheel is there to lock the ball in position. The handwheel can be used to isolate, but with back pressure. The Dual valve can work in the horizontal and vertical position. >>more
DUAL‘s Flo-Stop Valve (DFSV) has a reinforced stainless steel ball. The unique design of the valve allows free movement of the ball. The ball lifts out of the liquid without any interference. As the pump stops, the ball falls back and positively locates in the stainless steel seat due to its own weight and back pressure of the liquid. The higher the pressure the better the secondary Linatex seal will seal. >>more
DUAL‘s Pump Protection Valve (DPPV) has been designed and manufactured to provide protection against excessive fluid temperature rise, within the pump housing. Low flow conditions can cause flashing, cavitation, vibration, bearing failure and damage to mechanical seals and pump housing. The DPPV valve is fitted to the suction side of the pump. >>more
DUAL‘s Rotary Disc Valve (DRDV) is a unique rotating gate valve designed specifically for heavy abrasive and corrosive slurries. The patented design allows the valve to cycle in heavy slurries without sticking. >>more
DUAL‘s Air/Vacuum Valve’s (DSARV) function is to automatically exhaust large volumes of air from the system when it is being filled and also to allow air to re-enter the pipe line when being emptied. The orifice size is generally the same size as the valve inlet and outlet. In Operation, when the system is filled, the fluid lifts the ball until it closes the orifice. The orifice will remain closed until the system is emptied. Air may enter the valve and displace the fluid while the system is in operation, however, internal pressure will continue to hold the valve closed. The valve will not re-open until the system pressure drops to near atmospheric pressure and the ball is no longer buoyant. >>more
DUAL‘s Slurry Knife Gate Valve (DSKG) is built with a cast SG Iron GR. 42 or fabricated body and features a heavy-duty stainless steel blade. Removable sleeves on either side of the blade provide a bi-directional bubble tight seal, with no metal parts in contact with the slurry. >>more
DUAL‘s Wafer Slurry Knife Gate Valve (DWSKG) is built with a steel body and features a heavy-duty stainless steel blade. Removable seats on either side of the blade provide a bi-directional bubble tight seal, with no metal parts in contact with the slurry. >>more
DUAL‘s High Pressure Slurry Knife Gate Valve (DHPSKG) is built with a cast SG Iron GR. 42 or fabricated body and features a heavy-duty stainless steel blade. Removable sleeves on either side of the blade provide a bi-directional bubble tight seal, with no metal parts in contact with the slurry. >>more