Datex-Ohmeda 7900 - Page 25

2/Theory of Operation
1503-0151-000 3/27/97 2-7
Figure 2-9
MOBO (Mechanical Over pressure Bleed Off)
The Mechanical Over pressure Bleed Off Valve is a mechanical valve operating
even if there is no electrical power. The MOBO has two functions. First, it serves
as a third level of redundancy to the ventilator's pressure limit control functions,
providing pressure relief at approximately 110 cmH
2
O. Second, the MOBO serves
as a backup in the event of a complete blockage of the exhalation valve system,
relieving circuit pressure at approximately 30 cmH
2
O under such failure conditions.
M
ec
h
an
i
ca
l
Overpressure
Bleed Off
(MOBO)
Drive Gas Check Valve
(DGCV)
S
upply
Gas
Hose
Manifold
Pressure
Transducer
Flow
Valve
P
ressure
R
egulator
Inlet
Filter
Gas
Inlet
Valve
(GIV)
2
5 psi
25 mm por
t
17 mm por
t
Exhaust
to Scavenging
System
Exhaust to
Ambient
E
xhalation Manifold
35 - 100 psi
Supply inlet