Dräger Narkomed 2B - Flowmeters

NM2B REPLACEMENT PROCEDURES (continued)
4.5 Flowmeters
The flowmeter tubes are held by compression in gaskets at the top and bottom
of each tube. Each upper gasket is seated in an adjustable retainer that allows
removal of the tube as shown in Figure 4-5. Access to the flow tubes and their
retainers requires removal of the plexiglass cover on the gas instrumentation
panel.
4.5.1 Disconnect all pipeline hoses and set the System Power switch to ON.
4.5.2 Close all cylinder valves except the O
2
valve.
4.5.3 Set the oxygen flow to 5 liters per min.
4.5.4 Open the other gas flow control valves to drain pressure from the
system.
4.5.5 Close the O
2
cylinder valve, and close the flow control valves. Press
the O
2
Flush valve to drain oxygen pressure from the system.
4.5.6 Set the System Power switch to STANDBY.
4.5.7 Remove the screws holding the table top to the machine and lift out
the table top.
4.5.8 Early models: Remove the flowmeter housing rear cover.
4.5.9A Early models: Remove the two screws (from the back) holding the
front plate at the top of the plexiglass cover. Hold the front plate as
the screws are removed from the back.
4.4.9B Later models (without the O
2
/N
2
O ratio alarm lamp): Remove the six
screws holding the flowmeter shield and vapor box cover panel, and
remove the panel.
4.5.10 Remove the O
2
flow control knob. The knob has two setscrews.
NOTE: If the knob must be rotated to allow access to a setscrew,
carefully note its position so that it can be re-assembled
in the same position with the "Off Stop" properly set.
4.5.11 Remove the two screws holding the knob guard in place, and remove
the knob guard. (For earlier machines with the bar-type knob guard,
the screws holding the guard assembly are accessible through the
back of the flowmeter housing.)
4.5.12 Remove the screws holding the plexiglass cover over the flow tubes
and gauges, and carefully remove the cover.
Rev. A
4-15
RETURN TO THIS MANUAL'S TABLE OF CONTENTS
RETURN TO CD-ROM TABLE OF CONTENTS