How to open the Maserati Geberi deflation valve?

A device used to protect turbines. Installed between the turbine and the throttle, when the throttle is increased, the rotor of the turbine rotates quickly and the pressurization pressure is also great. If the throttle valve is suddenly closed during gear shifting, the pressure in the intake manifold may be too high, resulting in pressure backflow and damage to turbine blades or bearings. At this time, the air leakage valve could not bear such a large pressure and began to discharge too high pressure. When the pressure drops to a certain level, it will close.