Siemens Maxum II PD PA AP Service Manual page 43

5. Insert the sample flow unit (15) into the valve body (7) over the stem (6). See the Liquid
Injection Valve Body (Page 39) illustration.
Note that the stem hole through the sample flow unit is tapered. This tapering is not readily
apparent when looking at the uninstalled sample flow unit, but it will be visible when it is
installed on the stem. The narrowest side of the hole in the valve body should face outward
(toward the vaporizer). The narrowest side of the hole will be apparent because it will have
the least spacing between the stem and the side of the hole. Newer sample flow units have
this orientation marked with an arrow.
6. Move stem (6) into filling position. This means that the stem should be "pushed in" towards
the control cylinder (1)
7. If you have completely removed the liquid injection valve, fit the flange (17) over the
vaporizer (16), and screw the valve body (7) and the flange together.
8. If the the flange plate (17) and vaporizer (16) were not removed from the analyzer, screw
the partially reassembled valve onto the already installed flange plate.
Figure 4-8
Belleville Washer Spring Adjustment
It may be necessary to adjust the amount that the Belleville washer springs are being
compressed. These washers should compress about 2 mm when adjusted appropriately.
This compression distance is called "spring travel" and it is adjusted using the following
procedure.
● Standard setting with 7 Belleville Washers: smooth round nut (11) extending about 0.5 mm
past end of the threads on the adjustment assembly (13).
● Standard setting with 8 Belleville Washers; about 0.5 mm of threads showing below the
round nut on the adjustment assembly (13).
The spring travel is not critical, but more compression distance should be used for higher
pressures (greater than 20 bars) and less should be used for low pressures (less than 2 bars).
Adjust accordingly.
Maxum II Valves and Oven Components
Service Manual, 10/2018, A5E42019844001
Orientation of Sample Flow Unit Hole
Valves
4.2 Liquid Injection Valve
43