Pressure drop at condenser

[GENERALCOOL]

Hi friends,

At Evapco documents regarding condensers I read that when a condenser works it has pressure drop during pipes and while it is idle , It has not any pressure drop and pressure of inlet would be same with pressure of outlet.

Would it be possible someone make it clear for me, Why when condenser does not work it has not pressure drop ?

Please see photo at below

14936

[hookster]

Friction pressure losses and changes in saturation temperature in the dynamic system (operating condenser)

[FaultCode]

Pressure drop is due to friction losses along the pipe length when the fluid is moving along the pipe.

When the flow stops the friction loss also stops leaving just the static pressure which is equal throughout the system.

[Segei]

We have pressure drop when someting (vapour, liquid) moving inside the pipe. Nothing is moving inside of idle condenser.