6-Monthly; Replacing The Microporous Disc - ABB Navigator 550 Operating Instructions Manual

Navigator 500
Hydrazine analyzer

8.2.2 6-monthly

1. Replace the microporous disc in the dosing chamber –
see Section 8.2.4.
2. Replace tubing if stained or age hardened – see Section
8.2.5, page 55.
8.2.3 12-monthly
1. Replace all the tubing in the wet-section using the internal
re-tubing kit – refer to Section 8.2.5, page 55.
2. Empty both the standard solution and reagent containers
and replace the O-rings on each filler cap.

8.2.4 Replacing the microporous disc

Referring to Fig. 8.2:
1. Close the external sample isolation valve to the
wet-section.
Warning. The reagent is extremely caustic and must
be handled with great care. Wear gloves and eye
protection.
2. Remove the special tool
3. Disconnect the QD coupling
container and remove the reagent tube
D
membrane clamp , located on the top of the reagent
E
dosing chamber .
4. Remove the two sample tubes
reagent dosing chamber
5. Unscrew the 2 x reagent dosing chamber bracket
H
retaining screws
chamber from the panel.
6. Locate the lugs of the special tool provided in the
recesses in the membrane clamp
reagent dosing chamber
clamp.
Remove the O-ring located in the recess of the membrane
clamp.
7. Carefully remove the old microporous disc with the end of
a screwdriver and dispose of it safely. Rinse the chamber
and fit a new (large) O-ring and microporous disc – part
number AW503 061 see page 70.
8. Fit the second new (small) O-ring securely into the recess
of the membrane clamp and refit the membrane clamp
D
using the special tool.
9. Refit the reagent dosing chamber
connect the sample inlet tube
54
A
from the holder.
B
on the reagent solution
C
from the
F G
and from the
E
.
and remove the reagent dosing
D
on top of the
E
and unscrew the membrane
E
to the panel and
G
.
10. Hold the reagent tube
beaker and reconnect the reagent QD coupling
enable the reagent to flow through the tube to displace
any air bubbles.
11. Connect the reagent tube
E
dosing chamber .
12. Establish flow through the new disc by clamping the
G
sample inlet tube
syringe to the reagent dosing chamber outlet
13. Connect the reagent dosing chamber outlet tube
the reagent dosing chamber
14. Allow approximately 1 hour for caustic dosage to be
established (the pH of the effluent at the sensor outlet
must be at least 10.5).
15. Calibrate as described in Section 5, page 23.
Fig. 8.2 Replacing the microporous disc
C
over a suitably positioned
C
to the top of the reagent
and applying suction from a plastic
I
.
E
.
OI/AHM550–EN Rev. A
B
to
F
to