presure relieve valve
Join Date: Nov 2000
Posts: 28
Likes: 0
Received 0 Likes
on
0 Posts
Over pressure
The B747 overpressure valves have clam shell outer doors that can be seen on the left forward fusalage below L2 door.
The valve its self will open at a diff. of 9.4 psid. and close as the diff.pressure falls, but the doors will remain open. They will have to be closed manually on the ground.
The rubber jungle will not happen with a high diff. which will give a low cabin altitude, but with a very low diff. which will give a high cabin alt.
The valve its self will open at a diff. of 9.4 psid. and close as the diff.pressure falls, but the doors will remain open. They will have to be closed manually on the ground.
The rubber jungle will not happen with a high diff. which will give a low cabin altitude, but with a very low diff. which will give a high cabin alt.
Join Date: Jan 2004
Location: Hopewell, Nova Scotia Canada
Posts: 29
Likes: 0
Received 0 Likes
on
0 Posts
B737-200.You cannot detect if a valve opened in flight visually. If the crew reported a sudden psi drop then it probably opened then closes when psi drops. I have seen pieces of insulation trapped by the valve when this happens. Also the valves are supposed to be function checked during a C check.
