Siemens Maxum II PD PA AP Service Manual page 41

5. Unscrew the sample line and pneumatic actuation control lines from the liquid injection
valve.
6. (If removing entire valve) Disconnect the carrier gas inlet line from the carrier inlet tube (18),
and disconnect the column from the vaporizer (16) outlet inside the oven and then remove
the valve.
7. (If not removing vaporizer and flange) Do not disconnect carrier gas or column. Unscrew
the valve body (7) from the flange (17) and pull out.
Disassembling the Valve
NOTICE
Clean Work Area Required
Perform all work on a clean dry surface to avoid contamination. Parts should be placed on a
clean lint free cloth and hands should be clean.
1. If vaporizer (7) and flange (8) were not removed from the analyzer, then skip this step.
2. Unscrew the valve body (7) from the flange (17) and vaporizer (16) and separate the
components.
3. Remove the 2 hex set screws (2) and remove the control cylinder (1).
4. Lift off the sample flow unit (15) and adjustment assembly (13) from the injection stem (6).
5. Remove the sample flow unit and the lens shaped gasket (if the gasket is not present it is
stuck in the vaporizer) to allow the Belleville washer plate springs (10) to drop out.
6. Pull the control piston (3) with stem (6) out of the valve body (7). Do NOT use any tools
such as a screwdriver as a wedge between the piston and the valve body. This would
damage the valve body and control piston.
Replacing the Teflon Gasket
Replace the Teflon gaskets if they show any signs of wear or contamination.
Procedure
1. Remove the gaskets (14) from the adjustment assembly (13) and vaporizer (16). To do this,
gently insert the tip of the stem (6) approx. 5 mm into the gasket and then tip to the side
until the gasket is loose and can be pulled out with the stem.
2. Insert new gaskets (14) into the adjustment assembly (13) and vaporizer (16). Use the
correct type gasket according to the application and temperature class.
3. There should be no play between the new gasket and the injection stem. It should be
extremely difficult to move the gasket.
Maxum II Valves and Oven Components
Service Manual, 10/2018, A5E42019844001
Valves
4.2 Liquid Injection Valve
41