What type of engine air bleed valves are installed on the CRJ-550?

• A. Manually operated valves
• B. ACSC controlled PRSOV
• C. Electrically actuated valve
• D. Pneumatic relief valve

Answer: (B)

The CRJ-550 uses a pressure regulating shutoff valve (PRSOV) that is commanded by the Air Conditioning System Controller (ACSC). The ACSC continuously monitors bleed-air demand and system pressures and moves the PRSOV to regulate the bleed air supplied to the environmental control system and anti-ice systems. This arrangement provides automatic, automatic-regulation of bleed pressure and secure isolation when needed, without manual intervention. It isn’t simply a manually operated valve, nor is it an electrically actuated valve in isolation, nor a separate pneumatic relief valve. The valve type and control method described—ACSC controlled PRSOV—best fits how the CRJ-550 manages engine bleed air.