Steam Trap on Condensate Line
Steam Trap on Condensate Line
(OP)
Hi,
I am looking to recover condensate from a heat exchanger back to the boiler. Condensate will gravity drain from the exchanger to a condensate tank and then it will be pumped back to the boiler.
I am confused as to whether or not I need a steam trap on the condensate line from the HX to the condensate tank. Is it recommended to recover the "flash steam" and send that back to the HX? Otherwise the steam is going to flash and vent to atmosphere when the condensate enters the tank. Can anyone advise. Thanks.
I am looking to recover condensate from a heat exchanger back to the boiler. Condensate will gravity drain from the exchanger to a condensate tank and then it will be pumped back to the boiler.
I am confused as to whether or not I need a steam trap on the condensate line from the HX to the condensate tank. Is it recommended to recover the "flash steam" and send that back to the HX? Otherwise the steam is going to flash and vent to atmosphere when the condensate enters the tank. Can anyone advise. Thanks.





RE: Steam Trap on Condensate Line
Unless you have a user that can take the steam at the operating pressure of the flash/condensate tank, you are going to lose the flash steam.
Or unless unless your Hx is putting out such subcooled condensate that there will be no flash steam from the condensate tank.
Well, I'm through guessing now.
rmw
RE: Steam Trap on Condensate Line
RE: Steam Trap on Condensate Line
Typically if the pressure differential is 75 psi you can return the flashed steam to a low pressure user, but this is not the case in my situation. I guess I just want to know why you need a steam trap on the condensate line from the HX to the recovery tank?
RE: Steam Trap on Condensate Line
RE: Steam Trap on Condensate Line
RE: Steam Trap on Condensate Line
RE: Steam Trap on Condensate Line
RE: Steam Trap on Condensate Line
RE: Steam Trap on Condensate Line
RE: Steam Trap on Condensate Line
rmw
RE: Steam Trap on Condensate Line
Assuming that you'll have a temperature control valve on the steam line ahead of the HX, then you must have a trap. Remember that the 40 PSIG will not always be available, such as at partial load - particularly at low load - you can have VERY low pressures in the HX and at the steam trap inlet as the control valve throttles-in. When the valve closes, you'll pull a vacuum in the HX. A vacuum breaker and having the condensate drain by gravity to a vented receiver is the correct arrangement.
The other way to pipe this, is to use a control valve on the condensate outlet, instead of a trap. In this arrangement, the steam is supplied at line-pressure, through an isolation valve. You'll have 40 PSIG steam pressure in the HX, and available at the condensate control valve inlet at all times. You can size the HX to permit subcooling of the steam, if you wish. But that's an economic decision.
RE: Steam Trap on Condensate Line
But remember that steam should enter the re-boiler near the saturation point by the means of de-supper heater otherwise you will have problem to recover the condensate .
Regards
ASA-KUWAIT
RE: Steam Trap on Condensate Line
Alternatively, if there is no use for the LP steam, then the heat exchanger trap should discharge directly to the atmospheric condensate tank.
RE: Steam Trap on Condensate Line