ABB Endura AZ20 series

Combustion Oxygen Monitor
Endura AZ20 Series Probe 5 Dismantling and Reassembly – Probe
34 IM/AZ20M–EN Rev. B
5.11 Replacing / Fitting Restrictors
Before proceeding:
 Ensure a restrictor kit is available – refer to Section 7.8,
page 44.
 Remove the probe from its mounting as detailed in
Section 5.4, page 14 (integral probe) or Section 5.5, page
14 (remote probe).
Referring to Fig. 5.19:
1. Remove the reference air (Ref. Air) fitting A and external
test gas (TG1, TG2) fittings B from the probe body inlets
C using a 14 mm A/F spanner (not supplied).
2. If fitted, remove existing filter pads
D from the probe
body TG1, TG2 and Ref. Air inlets.
3. If fitted, remove existing test gas restrictors E from the
probe body TG1 and TG2 inlets using the 3 mm A/F
hexagon key supplied in the toolkit with the probe.
4. If fitted, remove the reference air restrictor
F from the
probe body (Ref. Air) inlet using the 2.5 mm A/F hexagon
key supplied with the restrictor kit.
5. Remove any O-rings from the new restrictors and discard
(the seal between the restrictors and probe body inlets is
made by the metal-to-metal faces of the restrictors /
inlets).
6. Fit the 2 new (larger) test gas restrictors
G into the TG1
and TG2 inlets on the casting and tighten fully using the
3 mm A/F hexagon key.
Do not use thread sealant (the metal to metal seal is
sufficient).
7. Fit the new (smaller) reference air restrictor H into the
Ref. Air inlet and tighten fully using the 2.5 mm A/F wrench
supplied.
Do not use thread sealant (the metal to metal seal is
sufficient).
8. Fit new filter pads
I in front of each restrictor.
9. Refit the reference air (Ref. Air) fitting
A and external test
gas (TG1, TG2) fittings
B fitting using a 14 mm A/F
spanner.
Ensure fittings are leak-tight, use PTFE tape on the
threads if necessary.
10. Mark the Commissioning label
J on the probe to show
that restrictors are fitted.
11. Re-install the probe as detailed in the probe User Guide
(IM/AZ20P–EN).
12. Make gas supplies to the probe and electrical supplies to
the transmitter – refer to the transmitter User Guide
(IM/AZ20E–EN) for electrical supplies and the probe User
Guide (IM/AZ20P–EN) for gas and reference air supplies.
Note. The restrictors have extremely small orifices so
ensure this procedure is performed in a clean area.
Fig. 5.19 Replacing / Fitting Restrictors
B
A
C
B
I
G
H
F
E
TG2
Ven t
D
J