Issues regarding steam drainage in negative-pressure long-distance pipelines
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It is saturated negative-pressure steam at 90°C, with a DN350 pipe diameter, and is transported over a long distance of about 300 meters; there are some low points along the route, and steam traps have been installed at those low points. Is it necessary to install steam traps as well? Does this steam trap need to remain open for an extended period? Will running it for a long time have an impact on negative pressure?
A steam trap needs to be installed. Drain valves are installed at the lowest points of long-distance steam pipelines to remove water that accumulates due to condensation, prevent damage to the pipelines caused by water hammer, and maintain the efficiency and safety of the steam system. The drain valve does not need to remain open continuously; an automatic drain valve should be installed, as it can open and close automatically depending on the state of the fluid (steam or condensate). Keeping the drain valve open for an extended period has little impact on the negative pressure; its main function is to drain water without allowing external air to enter, thereby maintaining the negative pressure inside the system. .
We normally do not install a vacuum valve; instead, we use the liquid level to counteract the vacuum level.
A steam trap should be designed, but one suitable for this situation must be chosen; otherwise, air may be drawn in during steam drainage
I made a small liquid seal in U-tube form, but it doesn’t create a proper liquid seal; is it necessary to use a liquid seal groove?