Patent attributes
A bleed air pressure regulation system for an aircraft anti-icing system comprises a first, upstream pressure regulating valve and a second, downstream pressure regulating valve arranged in series in a bleed airflow path. The respective pressure regulating valves each have a regulating pressure chamber in fluid communication with a respective pressure setting valve. Each pressure setting valve is in fluid communication with a bleed air inlet upstream of the first, upstream pressure regulating valve. The first, upstream pressure regulating valve is set to regulate the pressure of the bleed air to a first pressure and the second, downstream pressure regulating valve is set to regulate the pressure of the bleed air to a second pressure which is higher than the first pressure.