how can we reduce the flash steam in condensate tank?

Hi,
how about installing one or more sprinklers inside your tank (prefarably on the top) and feed them with (de-mineralized) water (you can find water from the discharge line of any water feed pump nearby). In this way you can achieve to capture the majority of your flashing steam without losing its energy.

Add a short packed column section to the vent of the Condensate tank. Circulate condensate from the condensate tank through a heat exchanger to cool it slightly and pass it over the packing to condense the flash steam.

You will also need to protect the condensate tank from overpressure and vacuum with a weighted conservation vent or a manway vent.

Is it the lowest steam pressure you use?
If you have a lower pressure system you can use this flash to save some low pressure steam.

for maximum energy conservation pass the steam through bottom of condensate tank as by this method you can avoid energy loss second you can also use the jet flasher to get rid of steam.

instal a spiral flash steam pipe distributor at the bottom of the condensate tank. the spiral should have as many orifices as possible along the enitre spiral length and also the circumferunce of the pipe. this will ensure complete condensation of flash steam and also reduce the effect of water hammer resulting in the vibrations noticed in the walls of the condensate tank

Try to submerge inlet pipe ( no use of energy).

Also, what Ray mentioned.

Before doing any of the above, I'd make sure the steam in your condensate tank is actually caused by flashing condensate and not one of your upstream steam traps passing. A small amount of flashing from condensate is expected, but if you have enough there that it's causing an issue, it might be high pressure steam getting through.

Check Spirax-Sarco and Gestra catalogues or guides for standard parts and set up for condensate and make-up tank systems. Quantify the amount of losses - are they continuous or variable? Is condensate recovery/flash tank separate from make up incoming water tank or combined? For a combined flash/make up deaerator vessel you need some steam out to sweep out the incoming dissolved CO2/O2, normally requiring steam injection here. Is there unusual noise from any of the incoming condensate lines - could be steam blowing through a stuck or failed trap?

reduce pressure drop going to the condensate tank if tank can take a higher pressure.

Hi Sanket
Where are you based? Would you like a local Gestra engineer to visit?