Galvanic Applied Sciences AccuChrome MA2963, Operation Manual

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Revision 4 98 12/15/2018
The oven is set to 70
o
C. Take care that the user does not touch the heater
elements. It is suggested that the system be powered down for 20-30 min
before opening the compartment containing the valve, columns and
detector.
Substitution of components may impair suitability for the Class I, Division 1
Classification. All replacement components should be obtained from
Galvanic Applied Sciences to ensure compatibility.
9.6.1 Replacing the Valve
The most common cause of failure of a chromatograph valve is particulate
contamination in the sample or actuation gas. It is imperative that the
sample is clean and dry.
The chromatograph valve must be cleaned or replaced if it is found to leak. A leak in the
injection valve will typically be characterized by any of the following symptoms:
•
Elevated baseline,
•
Poor analyzer repeatability
• Poor back flush peak shape,
•
Shifted retention time of the back flush peak,
•
The presence of a second peak immediately following any valve actuation.
A model of a Valco 10-port valve is shown in Figure 9-3.
To change a valve:
a) Turn the analyzer to the ‘Halt’ mode.
b) Turn off the sample gas flow to the analyzer.
c) Turn off the helium gas flow to the analyzer.
d) Undo all fittings that go into the ports of the valve, including the valve actuation line.
Remember which connections were made to which ports.