A flow regulator includes a flow regulating part configured to receive at an inlet a working fluid at a first pressure and to release the working fluid at an outlet at a second pressure; a slide provided inside the flow regulating part and configured to move along an axis to reduce the pressure of the working fluid; a control part attached to the flow regulating part, the control part including a chamber; a spring housing provided in the chamber and connected to the slide though a shaft, the spring housing configured to move the slide along the axis; a cap provided in the chamber and facing the spring housing, the cap being configured to have plural blind holes; and plural pins extending along the axis and attached to the spring housing, the plural pins being configured to enter the plural blind holes.