Steam & Condensate Introduction
Operation of a Steam System
DRIP APPLICATION using a Thermodynamic Trap: Removing condensate from steam mains & steam supply lines Drip applications refer to removing the condensate that forms in the steam pipes (due to heat losses) as opposed to condensate that forms at the actual process. It is appropriate to have “Drip traps” placed 150 to 300 feet apart in the steam pipe line, and at any abrupt changes in direction or elevation. Air discharges through the separate air vent located at the end of the steam line.
Thermostatic Air Vent OPEN when air is present and CLOSED when steam tries to escape.
The Steam Trap discharges the Condensate & the Air Vent purges the air.
Incoming steam pushes air through the OPEN air vent.
AIR
STEAM
Outlet Pressure
Inlet Pressure
Drip Leg
Steam Pressure pushes condensate through the steam trap
Inlet Pressure (Steam)
Differential Pressure
Outlet Pressure (Condensate)
–
=
50 psig
– 0.0 psig
= 50 psi
Thermodynamic Steam Trap (TD600S) used in Drip Application
Condensate Discharge
PROCESS APPLICATION using a Float & Thermostatic (F&T) Trap : Removing condensate and air from a steam jacketed kettle
Operation – Condensate discharging from system Steam now fills the jacket at full operating pressure, heating the contents of kettle. Steam is condensing and the steam pressure in the kettle is being relied upon to push the condensate through the steam trap and into the condensate return line.
Start-Up – Air discharging from system Air that entered the system during system shut-down must be purged so that steam may enter. Float & Thermostatic steam traps contain a separate thermostatic air vent for discharging air during system start-up. Note: Additional air vents may be installed on the process or other high points in the system.
Inlet Pressure
Steam pushes air through the Air Vent in the Steam Trap and also through the auxiliary air vent.
Air
Steam is now at Full Pressure and all Air is discharged from the system
Air Discharging Air Vent placed at high point in system. Air vent is Open when air is present.
Air Vent CLOSED
Steam Jacketed Kettle
Steam Jacketed Kettle
Inlet Pressure
Air Discharging Steam Pressure pushes air through the Thermostatic Air Vent in the steam trap
Steam Pressure pushes condensate through the steam trap
Air
Float & Thermostatic (F&T) Steam Trap contains separate thermostatic air vent
Float & Thermostatic Steam Trap
Air
Outlet Pressure
Discharging Condensate
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