Valve selection
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For circulating water pipeline valves with large diameters (≥DN800), soft-sealed butterfly valves are generally chosen, but they often experience internal leakage. Hard-sealed valves can also leak internally due to obstructions. Do any of you have any new insights on this?
Replace it with a three-eccentric disc valve; this can prevent internal leakage...
Considering water quality and by adding filtration devices, the number of operations of a soft-sealed butterfly valve is around 10,000 times; when frequent operation is required, a hard-sealed valve should be considered.
The price of the three-eccentric hard-sealed version for DN800 is insanely high; it’s not a viable option. The prices of centerline butterfly valves, double-eccentric butterfly valves, and triple-eccentric butterfly valves are not in the same price range. Can large gate valves be used?
There aren’t any great ideas. Generally, soft-sealed butterfly valves are used for circulation water lines; considering costs, this is the most economical option. Also, it’s not a big issue if there is some internal leakage in the circulation water line
Internal leakage in valves is a quality issue related to the valves themselves. It’s common for butterfly valves to not be able to close properly; they are generally used only in cooling water systems. The reason for this is twofold: firstly, it’s cost-effective, and secondly, these valves remain open at all times. When maintenance is required, the entire system has to be shut down, but this isn’t a problem. If something keeps getting stuck inside the valve, it’s necessary to find the source of the problem – whether the pipelines have been cleaned before use, and whether filters are installed at the pump inlet! :loveliness:
From your description, it seems that the main reason for internal leakage in the valve is the excessive amount of impurities in the circulating water. It is recommended to choose centrally symmetric disc valves, as they offer better cost-effectiveness. The key component of such valves is the rubber seat, and the quality of the rubber material is very important. As we all know, rubber is relatively resistant to wear; therefore, it is crucial to find manufacturers with reliable quality. A recommended manufacturer is KEYSTONE, whose products are manufactured in Shenzhen. KEYSTONE is well-known worldwide as the largest disc valve manufacturing company – its products are reliable, though they are more expensive than those produced by domestic manufacturers
Valves for circulating water generally use soft-sealed wafer butterfly valves, primarily due to economic and practical considerations. Gate valves and triple-eccentric butterfly valves are not very suitable. It seems to be a problem with the water quality – there are too many particulate impurities in it. Check whether there is a problem with the filtration device in the circulating water plant, and also check if there is an issue with the filter of the circulating water pump. This post was last edited by lily9666 on 2009-3-12 13:34.]
Replace ordinary butterfly valves with eccentric hemispherical valves.
For the real estate market, it’s not the 800-caliber version; tell others to buy ball valves instead! ! ! Personal suggestion: gate valves offer better cost-performance