What is the pipe on the turbocharger bypass valve for?

Function: When the pressure is too high, the waste entering the volute will be discharged by-pass to reduce the working intensity of the supercharger.

The pipeline is an intake bypass valve, which is also commonly called an intake pressure reducing valve. Installed on the intake pipe near the throttle, it is the original pressure relief device for most turbocharged engines when they leave the factory. ?

Because the turbine is driven by the power of exhaust gas, the throttle is closed when it is closed during driving (such as shifting gears and braking suddenly). Turbine blades (compressor wheels) still keep rotating under the action of inertia. At this time, due to the truncation of the throttle and the continuous pressurization of the blades, the air pressure in the intake pipe (between the throttle and the turbine) will rise rapidly.

In order to protect the supercharging system, when the pressure reaches a certain limit value, the intake bypass valve is opened to guide excess air (pressure) back between the filter and the turbine to realize the function of depressurization protection.

Extended data

Air intake and pressure relief valves are divided into two types: internal and external, which are installed between intercooler and throttle.

1, internal line type:

Most of the original turbocharged cars used internal pressure relief valves. Because the boost value of the original car is generally low, the internal pressure relief valve is generally small and not too eye-catching. Because the gas discharged from the internal pressure relief valve will eventually flow back to the intake pipe, it will cause partial pressure relief and have a great negative impact on the working efficiency of the turbocharger. Moreover, plastic materials are easy to age and deform in the high-temperature engine compartment, and the service life is greatly reduced.

2. Outflow type:

The external circulation air inlet and pressure relief valve came into being to solve this problem. Because the external circulation air inlet pressure reducing valve directly discharges the returned excess gas into the atmosphere, there is no problem of incomplete pressure relief, which can effectively improve the working efficiency of the turbocharger and thus improve the power output performance of the engine.

References:

Baidu encyclopedia-air inlet and pressure reducing valve