One Pipe ''Relief'' System

One Pipe Steam Relief System
 
If the steam system is very big it is even less desireable to have all the radiators draining back into the steam main, even if the steam and condensate were to flow in the same direction. In this instance there is no condensate what so ever that drains into the main. All the radiators drain back to risers that are each dripped and even the runouts to the risers are dripped. The system is called a relief system because all the condensate is relieved in places other than the steam main.