Ametek 933S, Operator'S Manual

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Maintenance and Troubleshooting
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6-57
Examining and Caring for the Flamepaths
The analyzer is designed with flamepaths that will prevent flame propa-
gation from within the analyzer’s Ex d Electronics Enclosures to the
outside, should an internal explosion occur. For other flamepaths not
mentioned here, contact AMETEK.
The flamepaths on the analyzer consist of:
• The Ex d Upper and Lower Enclosure flanges, cable entry ports, and
the Digital Communications Port Body-Cover joining surfaces.
During each analyzer maintenance, use a feeler gauge to check the
flamepath gap of the Upper and Lower Enclosure flanges (enclosure
doors and housing joining surfaces). The surfaces of the flanges must
be flat (0.05 mm or better) and the minimum flamepath must be at
least 38 mm. When the bolts are tightened, the gap must not exceed
0.1 mm (Group IIB) or 0.04 mm (Group IIB+H2).
Check the Cell Heater Block and Cell Heater Block Lid (if used, option-
al) joining surfaces. The flamepath gap must not exceed 0.1 mm (Group
IIB) or 0.04 mm (Group IIB+H2).
Also, check the Communications Port Body-Cover joining surfaces.
These joining surfaces must be flat (0.05 mm or better) and the mini-
mum flamepath must be at least 7 mm. When the bolt is tightened, the
gap must not exceed 0.1 mm (Group IIB) or 0.04 mm (Group IIB+H2).
If any gap exceeds its maximum flamepath gap value, contact
AMETEK for advice. See Warning below. In all locations, use
stainless steel fasteners with yield strength ≥450 MPa (65,300 psi).
• All separable joints in the Heated Column Block Assembly. These parts
include the joining surfaces of the Column Block Assembly housing
and its cover, and the connecting tube to the analyzer.
During each analyzer maintenance, use a feeler gauge to check the
flamepath gap of the Heated Column Block flange (Column Block
and Column Block Flange joining surfaces). The gap must not exceed
0.05 mm (Group IIB) or 0.04 mm (Group IIB+H2); if the gap exceeds
this value, contact AMETEK for advice. See Warning below.
• Enclosure (Electrical) Connection Seal, Cell Window Housing, and
Solenoid Junction Box.
These areas are not typically disassembled for general or preventive
maintenance and therefore should remain intact. However, if there
is ever any indication of damage or wear to these flamepaths, use a
feeler gauge to check the flamepath gap.
The flamepath gap must not exceed 0.1 mm (Group IIB) or 0.04 mm
(Group IIB+H2); if the gap exceeds this value, contact AMETEK for
advice. See Warning below. For the dimensions of other flamepaths
not mentioned here, contact AMETEK.