Patent ID: 8757197

Claim:
A combination of an automatic pressure regulator and a thermal type mass flow rate regulator, wherein the combination comprises: (a) an automatic pressure regulator that includes (i) a pressure regulating valve comprising a driving unit, wherein the pressure regulating valve has a range of control pressure of −0.07 MPaG to +0.7 MPaG; (ii) a control pressure detector disposed on an output side of the pressure regulating valve; (iii) a controller operably connected to receive as input a detected pressure value P 2 from the control pressure detector and a set value Pst as a control pressure; and (iv) a proportional control system, wherein the controller supplies a control signal to the driving unit of the pressure regulating valve using the proportional control system in order to perform opening regulation of the pressure regulating valve, wherein the proportional control system is a control provided with a proportional action that brings about a residual deviation in control pressure, and wherein the proportional action of the proportional control system brings about a residual deviation in the control pressure by disabling an integral control action from a state in which proportional-integral-derivative (PID) control is enabled; and (b) a thermal type mass flow rate regulator, wherein the automatic pressure regulator is operably connected to supply pressure of gas to an upstream side of the thermal type mass flow rate regulator, and wherein the automatic pressure regulator is disposed to regulate a flow rate of gas supplied to an apparatus for semiconductor manufacturing, chemical product manufacturing or pharmaceutical manufacturing, and the automatic pressure regulator is disposed to prevent an overshoot with respect to a temporal flow-in of gas supplied from the thermal type mass flow rate regulator from occurring when the flow rate of gas is changed or when the gas supplied from the thermal type mass flow regulator is switched to another type of gas.