Lifting condensate from a steam trap is an important consideration. All steam traps will lift condensate with the amount of lift possible a function of the pressure at the inlet of the trap.
28" = 1 PSI
A column of water 28" high will exert a pressure of 1 pound per square inch at the base of the column. Conversely, it requires 1 psi of pressure to lift a column of water 1'.
Rule of Thumb # 1-
Each pound of pressure at the trap will lift condensate 12". For application where the steam trap is connected to a constant pressure supply, use our rule of thumb.
Many process steam applications will include a control valve regulating the steam flow to the equipment. Control valves can assume a percentage of open to feed the proper amount of steam to a piece of equipment. As the amount of opening on a control diminishes, the pressure drop across the control valve increases. When the control valve closes, there would be no pressure at the trap.
Rule of Thumb # 2-
Do Not Lift Condensate From a Trap Supplied by a Control Valve.
For this type of application, the condensate must be pumped to the return system. Pump types include motor driven and steam powered. Motor driven pumps are less costly but care must be used to provide a flash receiver to cool the condensate to ~ 200 F for proper operation. Steam powered pumps can handle condensate at high temperatures but are more costly to purchase.
Proper condensate pump selection is a function of the specific details of your application and your budget. If you need assistance, give us a call to discuss your requirements.
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