Steam Turbine Condenser Make Up

Put a restriction in the discharge piping from the pump into the condenser, such as a "Q-max orifice."

Correct! (as you already know...just an effort to convince the OP)

Is the valve controlled by computer or is it an air operated control? You should be able to get your technician to create setpoints for the valve to operate at.

If you provide absolute pressures, desired flow rates, pump and piping details I am sure some of us would have fun playing with the numbers to help.

<Tornado> I am not familiar with a Q-max, is it an ordinary remote operated valve or something for power plants I haven't seen yet?

Drew K

These are simply an orifice placed in the discharge piping to ensure that the pump runs enough to the left on its curve to avoid cavitation. Refrigerant pumps often feature this. It also prevents motor overloading, which usually isn't as much a concern. Q is just the term for flow.

Sounds like it would be good in conjunction with a control valve. It is often important to regulate your rate of flow of the makeup water.

Not sure what else to think for the O.P. Perhaps we need to know more about the problem.

Drew K

I think using an orifice can not solve the problem because i simulated it with closing the pump discharge valve but it was not successful. In addition , as i sad before , elektromotor overload is one of the several problems witch that vacuum makes.

the motorized valve here operate as on/off valve and is not a control valve.

really I'm looking for an experimental or innovative general solution to block this vacuum in the condenser during make up.

BR!

Try bypassing the pump when the condenser is operating (under vacuum). The pump should only be needed to provide make up water during shut down conditions (no vacuum).