a blow off valve - Its purpose is to prevent compressor surge, and reduce wear on the turbocharger and engine. Blowoff valves relieve the damaging effects of compressor "surge loading" by allowing the compressed air to vent to the atmosphere, making a distinct hissing sound, or recirculated into the intake upstream of the compressor inlet.
-reference wikipedia
operation:
a BOV should open in 14.7 atmospheric pressure of 5hg of vacuum at manifold pressure. under Wide open throttle the valve plunger closes and creates a boosted environment depending on power added application(turbo or supercharged). when throttle plate is closed the valve opens and dumps the excess air.
most common break down illustration is:
here is the example of diaphram
adjustment screw plate & tensioned spring.
valve plunger with o-ring seal
adjustment screw
some valves have filters to help the valve with reliability. it prevent materials from damaging the diaphram.
-reference wikipedia
operation:
a BOV should open in 14.7 atmospheric pressure of 5hg of vacuum at manifold pressure. under Wide open throttle the valve plunger closes and creates a boosted environment depending on power added application(turbo or supercharged). when throttle plate is closed the valve opens and dumps the excess air.
most common break down illustration is:
here is the example of diaphram
adjustment screw plate & tensioned spring.
valve plunger with o-ring seal
adjustment screw
some valves have filters to help the valve with reliability. it prevent materials from damaging the diaphram.
