Valve proves its worth
October 2003
Valves, Actuators & Pump Control
Mitech recently subjected its Valvtechnologies' ball valves to various test factors to determine if there could be a cost saving in the manufacture of the instrument as well as carrying out test comparisons with a competing 80 mm plug valve.
All secondary air pump discharge valves are fitted with limit switches that enable Mitech to monitor every cycle. When a valve is changed, a counter is manually reset to zero on the DCS control system. The VT valves are switched by a double acting actuator with an air supply of 550 kPa. Both valves were tested in the same process conditions. The medium consisted of 60% slurry and 40% secondary spillage and a copper spent solution with a pH of 2,2. The pressure drop over an open or closed valve was 380 kPa and 1050 kPa respectively, while the flow rate through the valve was 180 m3/h. The temperature of the solution was 60°C and the velocity through the valve 20 m/sec.
The results proved that the main advantage of the VT valve is the fact that its Belleville spring washer exerts a pressure of 450 kPa on the ball at all times, preventing any solution from entering the seals around the shaft. As it is a full bore valve, there was no obstruction of the flow, as in the case of the opposition's plug valve. The face-to-face of both valves are the same. A disadvantage of the VT valve is that it is twice the weight of the plug valve, thus an increase in the safety factor is required, but as the frequency is so low, the risk is reduced.
Mitech's final results indicated that the other plug valves lasted anything between 12 000, 18 000, to 24 000 cycles, with a maximum of 28 000 cycles completed, although maintenance costs were high due to repeated valve failure. The VT valve in comparison, is currently on 98 000 completed cycles operating at maximum efficiency.
For more information contact Hennie Pretorius, Mitech, 011 462 2160, [email protected], www.mitech.co.za
Further reading:
Duplex valve improves continuous production at Gauteng manufacturing facility
Valves, Actuators & Pump Control
In a recent installation at a Gauteng-based manufacturer of household and personal care products, Allmech provided a tailored water treatment solution to ensure a consistent supply of soft water for steam generation, an essential element in the client’s 24/7 production cycle.
Read more...
Ultra-durable stainless steel submersible pumps
Valves, Actuators & Pump Control
KSB Pumps and Valves has launched a rugged stainless-steel submersible pump range designed for deep borehole use and other demanding freshwater and saline pumping applications.
Read more...
New wastewater pump for local municipalities and industries
Valves, Actuators & Pump Control
The latest wastewater pump from KSB Pumps and Valves is making waves in the industry due to a host of new features that provide users with an ultra-durable long service pump with fewer blockages and a lower maintenance requirement than traditional pumps.
Read more...
The critical role of check valves in fluid systems
Valves, Actuators & Pump Control
In fluid power systems, the performance and reliability of the entire operation often hinge on components that are small in size but significant in function. Among these, the check valve stands out as a fundamental yet frequently overlooked element.
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...
Pumps lead the way with advanced technology
Valves, Actuators & Pump Control
The KSB GIW MDX pump has consistently represented a major leap forward in mill duty applications, with KSB relying on customer feedback to improving the design continuously.
Read more...
Wireless leak detection valve
Valves, Actuators & Pump Control
Designed to prevent water leakage by automatically shutting off the water supply when a leak is detected, the Runxin F104 wireless leak detection valve is one of the latest offerings from Allmech.
Read more...
Ball valves and actuators optimise HVAC performance
Schneider Electric South Africa
Valves, Actuators & Pump Control
Schneider Electric offers the full range of innovative SpaceLogic and EasyLogic ball valves and actuators. These cutting-edge products are designed to optimise HVAC system performance, ensuring comfort and energy efficiency in commercial and residential buildings.
Read more...
Alfa Laval expands hygienic valve portfolio
Valves, Actuators & Pump Control
Alfa Laval is expanding its hygienic valve portfolio by introducing the Unique SSV pressure relief valve and the Leakage Detection butterfly valve, alongside new smaller sizes of the Unique Mixproof CIP and Unique Mixproof process valves.
Read more...
Preparing pump systems for adverse weather conditions
Valves, Actuators & Pump Control
As the severity of storms in South Africa increases, so has the rush of sediment-laden water become a major issue and a significant challenge for irrigation. When sediment levels rise to just 10 grams per litre or more, the risk of pump wear and dam silting increases dramatically.
Read more...
printer friendly version