Abstract: A back pressure regulating device can be incorporated either into a fuel cell test station or into a fuel cell power module. For each of fuel can oxidant lines, it provides a gas pressure regulator. The pressure regulator is controlled by a pilot gas, supplied, preferably, through a pressure regulating valve and a three-way valve. Another port of the three-way valve provides a vent through a check valve and a needle or other flow control valve. The needle valve is connected to both check valves for the pilot gas lines for the fuel and oxidant. In normal operation, the pilot gas pressure, regulated by the pressure regulating valve, is supplied to the appropriate pressure regulator to control the respective fuel and oxidant gas pressures. On shut down or in case of power failure or the like, the three-way valve defaults to a condition in which it connects the pressure regulator through the respective check valve to the needle valve.