Pneumatics 101
WHY DO ROSS POPPETS POP?

ROSS poppet valves pop open and closed almost instantly. The unbalanced design of ROSS poppet valves makes them shift positively and seal well. Surface areas of the piston poppet and the inlet poppet are carefully calculated to produce strong shifting and sealing forces in each direction.

The following illustrations show the forces acting on the valve in both actuated and deactuated states. The forces shown are for a Series 27 valve with 1/2" to 1" ports. Other valves have similarly proportioned forces.

The only friction to be overcome in the movement of the valve is the U-cup seal on the piston poppet, and the spindle in its guide at the bottom of the valve. The frictional forces at both these points are insignificant in relation to the forces acting on the valve.

NET UPWARD FORCE: 85 lbs.
This force keeps the inlet poppet well sealed.

2 - VALVE ACTUATED

NET DOWNWARD FORCE: 75 lbs.
This force moves the valve element downward once pilot pressure is on the piston poppet. When the inlet poppet opens, the full force of 160 lbs. on the piston poppet moves the valve element downward.

3 - VALVE ACTUATED

NET DOWNWARD FORCE: 52 lbs.
This force seals the exhaust poppet and holds the valve element open.

4 - VALVE NOT ACTUATED

NET UPWARD FORCE: 108 lbs.
This force initiates the return of the valve element to the closed position. When the valve closes, the cycle is complete and the valve is again in position 1.

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