Had the above fault and associated pack was locked out by Maint.
On the bleed page the associated bleed valve on the same side was showing closed, however it indicated bleed pressure of approx 40 psi and precooler outlet temp of 100 degrees.
If the valve is closed why are these indications present?
The pack valve was locked closed, you still had bleed air available up to the valve , the pack valve controls bleed air flowing into the pack it doesnt control bleed air from the engine, thats regulated by the PRV and the HPV.
But pack valve was closed and bleed valve closed, but still bleed air pressure and precooler outlet temp was displayed in green, approx 40 psi and 100 degrees.
The engine bleed valve opens and fills the pneumatic duct with hot air at 40psi. There are no leaks, and the pack is off. The bleed valve will modulate towards closed to maintain the pressure, and may close completely.
If you opened the Xfeed valve, the bleed valve would immediately open again.
Not unusual. On the B767 there is a statement in the MEL that this will happen.
Linear Mode
