Exhaust gas vent valve device for exhaust gas driven turbocharger

In an exhaust gas driven turbocharger comprising a turbine wheel chamber of said turbocharger, a housing for said chamber, an exhaust gas induction passage formed in said housing for directing the exhaust gases to the turbine wheel chamber, a turbine exhaust passage formed in said housing for discharging the exhaust gases from said turbine wheel chamber, a first bypass passage extending through the housing from said exhaust gas induction passage, a second bypass passage extending through the housing from said turbine exhaust passage, the improvement comprising an exhaust gas vent valve comprising a third U-shaped bypass passage with the ends thereof aligned with said first and second bypass passages for directly interconnecting said first and second bypass passages to form a compact structure, and a valve body disposed in said third bypass passage and responsive to variations in pressure of the air delivered from a compressor of said turbocharger so as to open and close said third bypass passage, said exhaust vent valve being directly mounted on said turbocharger and being an integral structure that can be removed from said turbocharger without affecting the operation thereof.