How can a triple-eccentric butterfly valve achieve tight sealing and prevent leaks?
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The current fermentation process uses triple-eccentric DN200 butterfly valves; the operating conditions involve a pressure of 0.15 MPa on one side, with a temperature of around 40 degrees – occasionally reaching 130 degrees, but for only short periods of time. The issue of internal leakage remains unresolved. Does anyone have any experience or insights in this regard?
Adjust the limit bolt of the valve, or remove it to check whether there are any scratches on the valve’s sealing surface. Under normal circumstances, there are only these two possibilities
Generally, the set screw is adjusted first; if the requirements for use are still not met, the valve is disassembled for inspection. It is found that the valve core is loose or displaced, and after repair, internal leakage occurs again within one or two days, which leads the valve manufacturers to give up on dealing with such valves!
Switch it; under these operating conditions, zero leakage is entirely possible. Three-eccentric butterfly valves can be opened and closed while under pressure, and those of high quality can withstand pressures of up to several hundred kilograms.
What medium was it passed through? The triple-eccentric butterfly valve provides better sealing as the pressure increases. Under these operating conditions, the pressure and temperature are not high, so a triple-eccentric design is actually not necessary.
Usually, after identifying the problem, one should know the cause of the fault. If the valve is being used within its specified conditions, then determine whether the overheating issue exceeds those operating limits; if so, it’s necessary to find out which part is damaged, and replacing the relevant components should resolve the problem. Fraud involving such valves is quite common. It’s better to keep a low profile; just replace it with an ordinary butterfly valve.
The valve manufacturers were changed several times, and in the end they gave up, refusing even to accept the final payment!
It would be great to be able to send a few photos; let’s see if we can come up with a solution. The video needs a panoramic view as well as close-ups of various parts. Thank you!
A soft-sealed butterfly valve will do. For sanitary applications, a sanitary soft-sealed butterfly valve can be chosen
This post was last edited by Old Cucumber Painted Green on March 19, 2019, at 09:45. The drawback of butterfly valves is their poor sealing performance; however, they are inexpensive. It’s better to use ball valves instead. For such low pressure levels, a floating ball valve is sufficient, and it isn’t very costly either