Badger Meter Hydrometer - Manual (Page 8)

Section I
Paragraphs 1-38 to 1-44
2. Determine cause of excessive pressure surges
and correct if possible.
3. Replace ruptured blowout disc.
1-38. MAINTENANCE.
1-39. GENERAL. Periodic cleaning of tubes and floats is
necessary to remove all deposit of foreign matter. A regular
schedule of cleaning should be adhered to depending on nature
of liquid being used. Deposits on floats or tube walls which
restrict flow will result in high readings.
1-40. CLEANING TUBES AND FLOATS
a. Relieve pressure on instrument. Do not drain.
b. Remove fillister head screws holding end cap to upper end
castings.
c. Insert float extractor rod (fib. 7), thread it onto float, and
lift out float. Handle floats carefully to avoid damage.
d. With the proper size brush, clean tube thoroughly with
eight or ten strokes of brush for entire length of tube (fig. 8).
e. Drain and flush with clean fluid.
f. Wipe float with clean soft cloth to remove all dirt and gum
deposit. Do not polish float with any abrasive.
g. Attach extractor rod and carefully lower float until float
rests on lower stop. Detach rod.
h. Install end cap and tighten screws. Clean remaining stages
in order.
NOTE
Use extreme care at all times to avoid damage to
float. Any damage will affect calibration of any
tube and result in inaccurate readings. Also be
sure that floats are not interchanged.
1-41. ALIGNMENT OF SCALES. Check alignment of
scales when cleaning tubes. Red index line on scale should
align with red index line on tube. If out of line, loosen screws
holding scale support posts, align scale and tighten screws.
1-42. PARTS REPLACEMENT.
1-43. PERMISSIBLE OVERHAUL. Flowmeters
are assembled and calibrated by trained personnel
under exacting conditions and no general
disassembly is ever required or recommended. For
6
this reason the repairs and replacements considered
are limited to replacement tube gaskets, valve seals,
metering tubes, and repair of damaged copper tubing.
1-44. REPLACING TUBE GASKETS (fig. 9).
a. Relieve pressure on instrument.
b. Remove top end caps and floats.
c. Remove end caps from bottom end castings to
drain unit.
d. Remove bezel with window from front of
instrument.
e. Remove screw holding scale to lower support
post. Loosen screw holding upper support post and
pull down to remove scale and upper support post.
f. Remove socket head cap screws holding glands in
position. Slip glands toward center of tube, lift tube
slightly and remove from instrument. Notice
arrangement of tube gaskets when removing. Note
that one aluminum backing washer, then the four or
five Buna N gaskets (to make ½-inch thickness) go
on tube and are slipped into gland in that order, then
the second aluminum washer is placed on the gaskets.
The thin fairprene gasket is then placed in gland.