Ideally, this is the pressure difference, which should be available between the pump’s head-flow curve and the system resistance curve (exclusive of the control valve pressure drop) at the ...

This is the minimum acceptable pressure head at the pump suction. The black curve shows the actual pressure head at the pump suction (H P + H ST – H FS).

The actual pressure at pump suction then corresponds to deaerator pressure of 59.45 psi + 34 psi (where 34 psi equals the static head minus friction loss) = 93.45 psi.

This would typically cause a low suction pressure and a low superheat. In heat mode, a dirty air filter causes low airflow across the condenser. This can cause extremely high head pressure. In heat ...

The more pressure a pump can deliver, the higher the head will be. “Of course, pump manufacturers cannot know your suction level parameters, so they calculate the pump’s total head,” he says.