The pwm is the butterfly valve, The difference is the PWM valve controls the hydraulic oil going to the pump so that the pump only spins as fast as slow as it needs to. Whereas in a electric butterfly valve situation, the pump is running a static speed and the butterfly valve is controlling the liquid product coming out of the pump . The PWM valve increases and decreases the hydraulic flow going to the pump so that the exact amount is always coming out of the pump, so no need for a butterfly valve downstream.

@FennigEquipment yup that's what I thought. Now if only we can get deere to code the software to tell the tractor to speed up or slow down the scv based on the gs rate controller needs. so then you don't need another electronic gizmo to go bad. With seedstar 4 that is already happening for vaccum control I think unless the valve is on the planter side

I run in furrow with a John Blue piston pump but don't have orifices? Just lines to each row with check valves to stop the dripping when lifted. I believe all lines are the same length.

@@LibTechsb is there a manifold present?

​@@FennigEquipmentright above the pump there's a John Blue CDS 'distributor' that splits into the 16 rows.