Hammering in condensate flash tank.

[abutt116]

Hi,

We have condensate flash tank at our plant. Condensate inlet pressure to the tank is about 75 psi. By flashing we are getting 55 psi steam. Problem we are facing is the hammering in the tank. There is vibration in the tank and the attached piping all the time.
Help in this regard will be appriciated.

Thanks.

 

[rmw]

You are probably beginning to flash the condensate well before it enters the flash tank. It may begin somewhere at 75 psig, but it is down to 55 by the time it enters the tank. Complete with the two phase flow and hammering associated with all that.

Can you put an orifice or restriction right at the flash tank entrance such that it would force the condensate to stay at an elevated pressure until just as it enters the tank?

I built some flash tanks many years ago and brought the condensate inlet in at the top and extended the inlet piping down into the tank pointed down and put a pair of concentric reducers welded back to back small side together to make a "flash device."

It worked well, and there was no hammer at the tank. I don't remember, however, how I sized the reducers. I think it was just like one or two pipe sizes smaller than the inlet pipe. In other words, if the condensate inlet was 6", then the reducers were 4 X 6.

rmw