Big motorized steam valve

if a globe style valve is located in a horizontal run it will present a dam in the pipe that will hold condensate back. If it is installed that way without a trap or way to drain condensate you will have hammer. If the valve is installed close to a riser it can drain back into the main. Consider that even steam in a vapor system has velocity and will move the condensate along the piping to a point where it will have to be drained or will cause damage. Once again, it's a steam system and you have three fluids to deal with, steam, condensate and air/non-condensables. Miss one and you have problems.
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