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PENBERTHY SERIES LC FLAT GLASS GAGES
INSTALLATION, OPERATION AND MAINTENANCE INSTRUCTIONS
8.2 Inspection of glass seating surfaces
Clean the glass seating surfaces on the liquid
chamber and cover with a soft metal scraper
(preferably brass) to remove all burrs, rust and
remnants of the previous gaskets and cushions.
Exercise extreme care to avoid gouging or
scarring gasket and cushion seating surfaces.
Use a known flat piece of metal the same
approximate length as the glass or a new
piece of glass and a thickness gage to check
flatness of each glass seating surface on liquid
chamber and under cover. Surface must be flat
within 0.002 inch (0.05 mm). If any one surface
is found to be beyond a tolerance of 0.002 inch
(0.05 mm), the entire gage must be disposed
of and replaced. Gasket seating surface must
have a final surface finish of 62 to 250 AARH.
WARNING
Flatness of glass seating surfaces outside
0.002 inch (0.05 mm) tolerance specified is an
indication of the gage having been overstressed
through repeated exposure to mechanical,
thermal or hydraulic shock during its previous
service. Operation of a liquid level gage which
has been overstressed will result in abnormal
stresses on the glass which may cause glass to
break. If surface finish is not in the 62-250 AARH
range, gasket may extrude under pressure with
resulting sudden release of pressure, leakage
of contained fluid, serious personal injury or
property damage.
Glass seating surfaces should NOT be
machined to achieve seating tolerance. The
chamber and cover are designed for a critical
thickness to achieve the pressure/temperature
ratings. Machining glass seating surfaces may
result in non-compliance to the necessary
critical thickness due to material removal.
8.3 Reassembly
If all glass seating surfaces are found to be
within the 0.002 inch (0.05 mm) tolerance
described in the previous section, proceed to
obtain new glass, gaskets, cushions and shields
(if used) and proceed to reassemble as follows
(refer to exploded parts views in Section 11
if needed):
1. Clean threads on bolts and nuts to remove
all paint, rust and scale. Apply a light coat of
oil to the threads.
2. For transparent gages, measure distance
between bolt heads of each section and
cut a 1 x 4 piece of wood for each section
as shown in Figure 5. Insert studs through
holes in half the covers, thread nuts flush
with ends of studs and place covers on cut
1 x 4 pieces of wood along bench, side by
side, with liquid chamber. Use chamber to
space covers and line them up with vision
slots.
3. For reflex style and belleville reflex style
gages, grip nipple on one end of liquid
chamber with vise and hold up the other
end with a 2 x 4 or suitable prop as shown
in Figure 3. Lay out covers side by side
with liquid chamber. Slide all U-bolts on
chamber to their approximate location,
using covers to space U-bolts.
4. For transparent belleville style gages, insert
studs through holes in half the covers,
place four Belleville washers under nut with
pointed end toward the nut (see Figure 2),
thread nuts on stud and lay out covers on
cut 1 x 4 pieces of wood along bench, side
by side, with liquid chamber. Use chamber
to space covers and line them up with vision
slots.
5. Install rubber band around each piece
of glass and cushion, then place glass
centered inside each cover.
WARNING
Separate installation instructions are supplied
with replacement glass. All instructions supplied
with the glass must be followed, as there are
precautions to be taken when handling gage
glass. Among the precautions is avoidance of
bumping or sliding glass against any surface and
inspection of individual pieces. Failure to follow
any of the replacement gage glass installation
instructions could result in glass breakage with
resulting sudden release of pressure, severe
personal injury or property damage.
FIGURE 5
Block of wood
8
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