9100c
2-26
M1207026
2.8.5 Reservoir and
bleed resistor
The reservoir (
10
) is a 200 mL chamber that dampens the manifold
(pilot) pressure pulses to the exhalation valve.
The bleed resistor (
11
) is a “controlled leak” from 0 to 10 L/min in
response to circuit pressures from 0 to 100 cm H
2
O. The small
quantity of pneumatic flow exhausting through the bleed resistor
permits control of the exhalation valve's pilot pressure by modulation
of the valve output. The bleed resistor exhausts only clean drive gas
and must not be connected to a waste gas scavenging circuit. The
output is routed away from the electrical components to make sure
that systems using oxygen drive gas meet the 10VA limitation
requirement for oxygen enrichment.
2.8.6 Bellows
pressure
relief valve
The Bellows assembly is the interface between drive gas and the
patient circuit in the breathing system. The pressure relief valve (or
pop-off valve) (
12
) in the bellows assembly limits pressure in the
patient circuit. Excess fresh gas is discharged through the exhalation
valve into the gas scavenging system.
The pressure relief valve is normally closed, maintaining
approximately 1.5 cm H
2
O in the breathing circuit in a no flow
condition, enough to keep the bellows inflated. It is piloted closed
during inspiration and remains closed until the bellows is refilled
during exhalation. If the pressure in the patient circuit exceeds 4 cm
H
2
O, the pop-off valve opens to exhaust excess fresh gas flow at a
rate up to 4 L/min.
11
10
M1207027
004
MANUAL−DOC, Technical Reference Manual, Technical Reference Manual for 9100c, English−default
Reproduced from the electronic master in MATRIX
