Figure 1 - resilient seated gate valve (smooth base on valve bore)
Figure 2 – metal seated gate valve (sump at base of valve bore)
Brief history and current status of metal vs resilient seated gate valves.
Before the resilient seated gate valve was introduced to the market (circa 1980’s), gate valves with a metal seated design were most commonly used for all sizes. Since then, resilient seated gate valves have become, by far, the most common choice for water and wastewater applications for sizes up to and including pipework diameters of 600mm. Metal seated gate valves are still more commonly used for valve sizes of DN700 and above.
However, with advances and improvements in manufacturing processes and equipment, resilient seated gate valves are readily available from AVK in sizes up to and including DN1000, and this will be increased further to DN1200 in the near future.
As you would expect from AVK, these larger resilient seated gate valves are designed, tested and manufactured in full accordance with the relevant standards (BS EN1074-1 & 2, BS EN558, BS EN1092-2 & BS EN12266-1) and are suitable for drinking water applications being manufactured from WRAS approved materials.
This downloadable report (click on the link - no login required) describes the various advantages of using resilient seated gate valves compared to the metal seated equivalent and shows that the following important benefits can be achieved:
• Leakage reduction
• Increase system efficiency
• Reduced operating torque and input effort
• Reduced costs for gearboxes and electrical actuators
• Reduces power consumption for valve operation
• Increased flexibility for valve installation
There is a legacy of using metal seated gate valves for water and wastewater applications on sizes above DN600. However, resilient seated gate valves are now readily available from AVK in sizes up to and including DN1000 (see Figure 5) and this size range will increase even further in the near future.
AVK offer a full range of resilient seated gate valves from DN50 to DN1000 and also offer metal seated gate valves from DN50 to DN1800. A wide range of options are also available.
We would welcome the opportunity to discuss your gate valve requirements please contact Graham Charnley directly on the link above.
Note: This paper was authored by Greg Morris, AVK UK Technical Manager, our specialist in valves for Dams, Reservoirs and Hydropower.