Pulsair Valve: Description and Operation

Fig. 75a Pulse Air Injection Reactor System. (typical):

This system uses exhaust pressure pulsations to draw fresh air into the exhaust manifold, through a series of pipes and check valves.

Engine operation causes positive and negative pressure pulsations in the exhaust flow which depend on exhaust valve position--is seated or not.
- If pressure is positive, the disc is forced to the closed position--allowing no air flow into the exhaust system.
- If pressure is negative, the disc will open allowing fresh air flow into the exhaust system.
- Due to inertia--at high engine rpm--the disc cannot respond to pressure pulsations and air flow into the exhaust system ceases.
- Throttle closure--during deceleration--momentarily causes air fuel mixtures too rich to burn which combines with air from the pulse air system becomes combustible and burns.