The last staging of Valve World Expo in Maastricht, The Netherlands, attracted around 9,500 visitors from Europe, Asia, North and Latin America and 454 exhibitors from 35 countries. The event occupied 99,460 square feet of exhibit space, reaching the capacity limits of the Maastricht exhibition center. As a result, Valve World Expo, 7th Biennial Valve World Conference & Exhibition, will move to Düsseldorf, Germany starting in 2010. Under the management of Messe Düsseldorf, Valve World Expo can continue to expand as part of the metallurgical trade fairs group “made by” Messe Düsseldorf.
As the organizer of 40 worldwide leading technology trade fairs, Messe Düsseldorf has for decades been specializing in the planning, organization and implementation of machinery and equipment trade fairs. Valves are used in almost all industrial sectors. Valve World Expo shows the rapid development within this technology sector particularly focusing on the segments shipbuilding, engine and vehicle construction, the chemical industry as well as the energy industry, the marine and offshore industry and the food industry.
Valve World Expo, the leading trade fair for valve technology, valves and gaskets, will debut at the fairgrounds in Düsseldorf from November 30 - December 2, 2010. The exhibitor applications were sent out this month and the first booth space bookings have already been received. The Valve World Conference, organized by KCI Publishing B.V., will take place concurrently.
For more information, go to www.mdna.com.
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The head and flow rate determine the performance of a pump, which is graphically shown in Figure 5 as the performance curve or pump characteristic curve. The figure shows a typical curve of a centrifugal pump where the head gradually decreases with increasing flow.
As the resistance of a system increases, the head will also increase. This in turn causes the flow rate to decrease and will eventually reach zero. A zero flow rate is only acceptable for a short period without causing to the pump to burn out.
Electrical Energy Equipment: Pumps and Pumping Systems
Figure 5. Performance Curve of a Pump
Pump operating point
The rate of flow at a certain head is called the duty point. The pump performance curve is
made up of many duty points. The pump operating point is determined by the intersection of the system curve and the pump curve as shown in Figure 6.
Figure 6. Pump Operating Point (US DOE, 2001)
Pump suction performance (NPSH)
Cavitation or vaporization is the formation of bubbles inside the pump. This may occur when at the fluid’s local static pressure becomes lower than the liquid’s vapor pressure (at the actual temperature). A possible cause is when the fluid accelerates in a control valve or around a pump impeller.
Vaporization itself does not cause any damage. However, when the velocity is decreased and pressure increased, the vapor will evaporate and collapse.
This has three undesirable effects:
- Erosion of vane surfaces, especially when pumping water-based liquids
- Increase of noise and vibration, resulting in shorter seal and bearing life
- Partially choking of the impeller passages, which reduces the pump performance and can lead to loss of total head in extreme cases.
The Net Positive Suction Head Available (NPSHA) indicates how much the pump suction exceeds the liquid vapor pressure, and is a characteristic of the system design. The NPSH Required (NPSHR) is the pump suction needed to avoid cavitation, and is a characteristic of the pump design.
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CARNEGIE, PA (November 18, 2008) - Red Valve Company, Inc. is pleased to announce the introduction of their newest product, the Series DX Slurry Knife Gate Valve.
The Series DX Slurry Knife Gate Valve is recognized as the most durable and user-friendly knife gate valve. It is designed especially for heavy slurry applications in the power and mining industries.
When the Series DX valve opens, the reinforced elastomer sleeves seal against each other and provide a 100% full port opening, minimizing turbulence which in turn minimizes wear. The seats isolate and protect all metal parts of the valve from coming in contact with the process. When the valve is closed, the sleeves provide a drop tight seal. Another unique feature to this valve is its ability to provide drop tight shut-off in both directions.
Each time the Series DX valve strokes, it is designed to discharge a small amount of slurry out of the valve, keeping the gate path and seat area clear of entrapped particulates. Unlike traditional knife gate valves, the DX prevents slurry build up in the seat area which might otherwise prohibit the valve from closing.
For more information on this new product and Red Valve’s full line of quality pinch valves, control valves, knife gate valves, pressure sensors, and rubber products, contact Red Valve Co., Inc., 700 N. Bell Ave., Carnegie, PA 15106, call us at 412-279-0044, or e-mail us at valves@redvalve.com. Visit us at www.redvalve.com.