Yes it will be when the valve initially opens. But the pressure in the bag (P1) then decreases, the mass flow through the poppet will decrease, so the force on the poppet will decrease. Thats what I'm trying to work out. I need to know the force on the poppet to work out when the valve closes again.
I need help with the following problem. I have attached a rough sketch showing what I'm looking at. Basically a popppet valve is closed over a vent. It is then pushed open by a force applied to the valve by the pushing rod. Their is a spring on the rod resisting this and providing a force...