Teledyne 3060e - Ultra Trace oxygen analyzer - Manual (Page 19)

Teledyne Electronic Technologies
Analytical Instruments
2-9
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• Valves
The analyzer sampling system utilizes three different types of valves.
Each valve is selected to prevent O
2
contamination of the sample
depending on its position and purpose in the circuit.
Air-Actuated Bellows Valves
These valves are normally closed in the sample system. They are
used to control the delivery through the sample system of the
sample, span or zero gas. The valve bodies are orbitally welded
in the system and the valve bonnets make a metal-to-metal seal
to the body. This valve system eliminates inboard and outboard
gas leakage. The valves are activated (open/closed) by com-
puter-controlled solenoid valves.
The valves have the following basic functions:
PV1: Sample gas to the Ultra Trace sensor.
PV2: Zero gas to the Ultra Trace sensor.
PV3: Zero gas to the calibrator.
PV4: Span gas out of the calibrator.
PV5: External span gas to the Ultra Trace sensor.
PV6: Sample gas into the scrubber.
PV7: Zero gas out of the scrubber.
PV8: Sample bypass vent.
PV9: Water to the Ultra Trace sensor.
PV10: Calibration bypass.
Metering Valve
The metering valve (labeled MV1 on the flow schematic) is used
to manually control the sparge rate to the sensor. The body of
the metering valve is orbitally welded and the bonnet is sealed to
the body with metal O-rings. The manual control knob is lo-
cated in the sensor compartment.
Solenoid Valves
The solenoid valves control the air flow to the air-activated
bellows valves. The solenoid valves are controlled by the micro-
processor. When de-energized, the valve outlet is open to
ambient air, allowing the air-activated bellows valve to close.