Condensate Drainage…Why It’s Necessary
Condensate is the by-product of heat transfer in a steam system. It forms in the distribution system due to unavoidable radiation. It also forms in heating and process equipment as a result of desirable heat transfer from the steam to the substance heated.
The need to drain the distribution system
Condensate needs to be drained before it becomes a barrier to heat transfer. Condensate lying in the bottom of steam lines can be the cause of one kind of water hammer. Steam traveling at up to 100 miles per hour makes “waves” as it passes over this condensate (A). If enough condensate forms, high-speed steam pushes it along, creating a dangerous slug that grows larger and larger as it picks up liquid in front of it (B). Anything that changes the direction—pipe fittings, regulating valves, tees, elbows, blind flanges—can be destroyed. In addition to damage from this “battering ram,” high-velocity water may erode fittings by chipping away at metal surfaces.
Once condensate is drained it is still valuable hot water and should be returned to the boiler.
Click to download Armstrong’s Steam Conservation Guidelines for Condensate Drainage which outlines steam basics as well has how to trap.