Mindray A7 Service Manual

A7™ Service Manual 046-006272-00 1 - 15
Theory of Operation Gas Flow
1.3.4.2 Gas Supplies
The A7 anesthesia machine supports three gas supplies: O2, N2O and AIR. All the gas supply
interfaces are designed based on IEC 60601-2-13, which prevents misconnection between different
gases. The A7 gas supply inlet assemblies comprise the pipeline gas supply inlet assembly and
cylinder gas supply inlet assembly.
The following describes the O2 gas flow. The difference between the O2 and the AIR/N2O limbs lies
in that the drive gas output and high-pressure O2 output are available at the upstream end of the
regulator (15) on the O2 limb. The configurations of other components are the same. The O2 pipeline
supply inlet assembly includes filter 10, pressure gauge 11, pressure relief valve 8, check valve 13,
pressure switch 14 and regulator 15. The cylinder gas supply inlet assembly includes the filter (10),
pressure gauge (12), pressure reducing valve (7), pressure relief value (9), check valve (13), pressure
switch (14) and regulator (15). Where, the pressure switch (14) and regulator (15) are shared by the
pipeline and cylinder gas supply limbs. The following figure is the block diagram.
The following table lists parameters of key components.
Name Supplier Description of Functions Key Index
Regulator Camozzi
Adjusts pressure and ensures
constant output pressure at the
regulator outlet.
Applied to compressed air, O2 and N2O .
Pressure range: 0.05 to 1 MPa (7 to 145 psi)
Flow: 160 L/min (At 10 bar (145 psi) inlet
pressure, 4bar (58 psi) outlet pressure, with
0.5bar (7 psi) drop)
Pressure
switch
AIR LOGIC
Reports an alarm when the gas
supply is insufficient. Pressure
switches are configured on the
O2, N2O and air limbs.
Precision: 0.5 to 100 PSI, +/- 0.5 tolerance on
the initial starting pressure
Alarm type: an alarm will be reported when
the gas supply pressure reduces to 32 PSI.
Pressure resistance: 300 PSI
Pressure
relief valve
Mindray Prevents gas pressure too high.
Startup pressure: 758 kPa±20 kPa (110 psi ±
2.9 psi)
Leakage volume requirement: The leakage
volume should be smaller than 5 ml/min for
a 600 kPa pressure relief valve.

Mindray A7 Specifications

General

Brand	Mindray
Model	A7
Category	Medical Equipment
Language	English