Integral Backpressure Transducer Valve
This valve combines an exhaust gas backpressure transducer within the diaphragm housing of the EGR valve. The transducer modulates EGR flow by venting vacuum in relation to exhaust backpressure. Backpressure is sensed between the inlet and the poppet/tapered stem of the valve. Flow rate is dependent on source vacuum, exhaust pressure, control setting and orifice size.
Poppet type valves are rapid opening. The flow rate through the valve is limited by the size of the valve orifice or the opening in the carburetor spacer plate.
Internal tapered stem type valves use a pintle which moves the tapered portion of the valve up or down against the valve seat. Gas flow rate is determined by the amount of movement of the taper off the seat.