Coke oven gas from steel mills
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Regarding steel plants and coke oven gas, the use of butterfly valves with triple-eccentric hard seals can lead to sticking of the valve disc, causing the valve to become stuck. How can this issue be addressed? Should hard-sealed ball valves be used, those with self-cleaning functions, or hard-sealed gate valves? Additionally, I would like to know how to deal with the static electricity problems associated with hard seals when dealing with gas
For coke oven gas, the requirements for leakage control aren’t very strict, so low-load butterfly valves of the open type can be used
If it is to be used as a truncation device, should a hard-sealed gate valve still be used?
Why use a hard seal? And why aren’t hard-sealed ball valves suitable?
A hard seal is used because it is resistant to high temperatures and wear, offering a long service life. In terms of sealing performance, ball valves outperform butterfly valves, as they achieve zero leakage in both directions. The butterfly valve meets the two-way ANSI Class V standard (no visible leakage). All of these can be met, and gate valves are also used. Since the butterfly valve is a three-eccentric metal-sealed butterfly valve, its opening and closing torque is very low. In contrast, as the diameter of a ball valve increases, the contact area of its sealing surfaces increases by a factor of two squared; as a result, the opening and closing torque of large-diameter ball valves is very high. Both ball valves and butterfly valves can achieve a long service life (over 15 years under normal use), but in the sealing mechanism of ball valves, non-metallic materials play an important role, whereas butterfly valves utilize a metal-to-metal sealing method; therefore, under normal circumstances, butterfly valves have a slightly longer lifespan. Butterfly valves of DN300 and above are also cheaper than ball valves of the same size
Reply to 6# laizi: Thank you, thank you. You’ve gone to so much trouble