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May 1, 2012
What do SKR Slanted Seat Tilting Disk Check Valves and aircraft have in common?
The SKR slanted seat tilting disk check valve made by VAG has been designed like the wing of an aircraft. Due to this design, the valve disk is fully opened even at minor flow velocities and the flow resistance (ZETA value) is reduced as compared to that of a not fully opened disk.
April 1, 2012
Why should butterfly valves never be installed directly downstream of pumps?
Butterfly valves should not be installed directly downstream of pumps to ensure optimum flow conditions. If butterfly valves are installed directly downstream of pumps, the flow against the disk might cause turbulences in the downstream pipeline system.
March 1, 2012
March 2012 What is cavitation and why should valves operate as freely of cavitation as possible?
Cavitation is the occurrence and dissipation of steam bubbles in fluids as a result of pressure fluctuations. According to Bernoulli's law, the static pressure of a fluid decreases as velocity increases. However, if the velocity is very high, the static pressure will fall under the evaporation pressure of the medium.
February 1, 2012
Feburary 2012 What is the advantage of a finite element calculation over current constructions?
A finite element calculation (FEM) makes it possible to calculate the distribution of stresses and probabilities of fracture in valve components in advance with the help of a computer.
January 1, 2012
Janurary 2012 Which advantages to DVGW-authorised valves have for users?
The German Association for Gas and Water, known as the DVGW, has been setting technical standards for a safe, reliable supply of gas and water for 150 years now. The association also encourages the exchange of information in the areas of gas and water and offers practice-oriented assistance.
December 1, 2011
December 2011 - Valves for cavitation-free regulation
Which valves can be used for cavitation-free regulation? Plunger valves are special control valves designed particularly for control purposes in the supply of water. In contrast to shut-off valves and butterfly valves, which normally perform purely shut-off regulation operations in pipeline systems, plunger valves meet the special requirements of regulating operation.
November 1, 2011
November 2011 - Plunger valves and media
For which media can plunger valves be used? Plunger valves are suitable for untreated water, drinking water and also for cooling water at temperatures of normally up to 50 °C. Another field of application is regulating the inlet air for the activation tanks in sewage treatment plants.
October 1, 2011
October 2011 - Installation recommendations for butterfly valves
Are there any special recommendations for the installation of butterfly valves? While butterfly valves up to DIN 1200 can be installed in horizontal pipelines with a horizontal butterfly valve or also with a vertical butterfly valve, it is recommendable to install only a horizontal butterfly valve in the case of dirty water.
September 1, 2011
September 2011 - Valves authorized acc. W 270
What is the advantage of valves with seals authorised according to W270 requirements? One of the most important aspects for drinking water installations is the choice of suitable materials. The materials and products must meet a wide variety of technical and mechanical requirements and, more than anything else, they also have to be completely hygienic.
August 1, 2011
August 2011 - flow velocities for shut-off valves
Are there defined flow velocities for shut-off valves? The DIN EN 1074-1 set of rules defines the permissible flow velocities for shut-off valves and butterfly valves.
July 1, 2011
July 2011 - Advantage of chambered seal profile
Which advantage does the chambered seal profile of the VAG EKN® Butterfly Valve have over traditional seal profiles? Chambered seal profiles guarantee reliable sealing even when flow velocities are high and they cannot be pulled out of the fastening between the holding device and the shut-off valve.
June 1, 2011
June 2011 - Comparison of GGG-40 and GG-25
What advantage does GGG-40 ductile cast iron have over laminated cast iron such as GG-25? Ductile cast iron is stronger and more elastic to give the material steely properties. Certain materials used to be prescribed for pressure-bearing parts (casing) in the water engineering and power plant construction industries.
April 21, 2011
May 2011 - GSK-Coating
Which advantage to valves with GSK coatings have over valves with traditional coatings? The European Quality Association for Heavy Duty Corrosion Protection (GSK) is recognised by the German Institute for Quality Assurance and Certification (RAL).
Addresse
VAG Water Systems (Taicang) Co.,Ltd.
No. 15 Guangzhou Road East
Taicang 215400
Jiangsu Province, China
Tel: +86 (512) 5357 5357
Fax: +86 (512) 5357 1825
E-mail: sales-cn@vag-group.com