The comparison between metal seated and resilient seated gate valves
Nowadays, there are two kinds of valve seat gate valves on the market, one is the resilient seated gate valves, and the other is the metal seated gate valves. And before the resilient seated gate valve was introduced to the market, gate valves with a metal seated wedge has been widely used.
Advantages of the metal seated gate valves:
1.Withstand high temperatures;
2.Severe service conditions;
3.Excellent corrosion resistance;
Advantages of the resilient seated gate valve:
1.Designed for zero leakage throughout valve life;
2.Low maintenance requirements Provides flexibility in design;
The comparison between metal seated and resilient seated gate valves:
About metal seated gate valves, the conical wedge design and angular sealing devices of a metal seated wedge require a depression in the valve bottom to ensure a tight closure. Herewith, sand and pebbles are embedded in the bore. The pipe system will never be completely free from impurities regardless of how thoroughly the pipe is flushed upon installation or repair. Thus any metal wedge will eventually lose its ability to be drop-tight. On the contrary, if the wear particles are less uneven than the surface, the accuracy of the relatively rough surface will be improved when the sealing surface is running in.
However, the resilient seated gate valve have a plain valve bottom allowing free passage for sand and pebbles in the valve. If impurities pass as the valve closes, the rubber surface will close around the impurities while the valve is closed. A high-quality rubber compound is soft enough to absorb impurities, yet strong enough to wash the impurities through when the valve is opened again. This means that the rubber surface will regain its original shape securing a drop-tight sealing. But the disadvantage is that the use of soft sealing materials is affected by the pressure and temperature that the sealing materials can withstand.
Therefore, recognizing your process condition is critical when it comes to choosing the appropriate seat for your specific application. If the selection is still unclear, speak with an engineer who is well versed in valve selection to help determine the best solution.
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