Taking a high pressue condensate line directly to a condensate pump receiver instead of a flash tank

Zoso

Is there a reason why it would be a bad idea to take high pressure condensate into a vented receiver of a condensate pump instead of a vented flash tank? This is an application where high pressure steam will be going to a modulating control valve on a coil. Due to modulation of the valve, condensate may not have enough pressure to gravity drain back to the deaerator, so I was going to take it to the receiver of a condensate pump. Obviously, it will flash in the receiver.

Now, I fully understand how it may be a "bad idea" to use high pressure steam in a heating coil application due to potential problems modulating such a large pressure difference. That aside, is there any reason why I can't just let the condensate pump receiver act as my flash tank? I won't be recovering flash either way, so why would I need a separate vessel to flash the condensate?

Pumpguy

Can't comment on the flash aspect of your question, but as stated in earlier post about high and low pressure steam systems and traps, condensate temperature could have an effect on pump performance and life.

Depending on actual condensate temperature, you may need to use a 2'NPSH type pump. These have a conventional single suction centrifugal impeller, and in front of that is an axial flow prop.

Another idea to consider is a Pressure Operated Transfer Pump. These devices use steam or air pressure as the displacement medium inside a chamber with inlet and outlet check valves and a float valve. They fill by gravity, and when filled the float valve opens to admit steam or air to displace the condensate out the outlet check valve.