Baseline Systems BHM Series Hydrometer - Manual (Page 35)

Hydrometers Operation and Maintenance Manual •
35
Maintenance 8” Models
HYDROMETER DIS-ASSEMBLY AND RE-ASSEMBLY
The dis-assembly of the 8” hydrometer is divided into the following logical assemblies:
• Register
• Hydrometer Cover
• Diaphragm Sub-assembly
• Lower Chamber Disc Sub-assembly
• Stem and Valve Cover Sub-assemblies
• Impeller and Flow Tube Assemblies
• Inlet Spider Assembly
Perform only those procedures necessary to inspect and replace parts as directed by the
troubleshooting procedures. It is recommended to replace the various o-rings and gaskets
during dis-assembly as well as to inspect certain other parts. All gaskets and o-rings must be
covered with grease prior to installation.
REGISTER
Dis-assembly
• Remove the register assembly as detailed on page 24.
• Using a large box wrench, loosen and remove the upper bearing bolt (8).
• Remove upper bearing o-ring (9). Inspect and replace as necessary.
• Using a screwdriver or a special key, loosen the guide tube nut (10). It is not necessary to
remove the nut.
Re-assembly
• Re-tighten the guide tube nut (10).
• Replace the upper bearing o-ring (9).
• Replace and tighten the upper bearing bolt (8).
• Replace the register assembly.
HYDROMETER COVER
Disassembly
• Loosen and remove the cover hex bolts (12) along with their nuts (61) and washers (14).
• Attach a hoist cable or chain to the rings on the hydrometer cover (14). Use the hoist to
lift the cover off of the hydrometer body. Be careful not to damage the impeller shaft.
• Lift out the guide tube (20).
• Inspect and replace as necessary.
• Inspect the cover o-ring (15) and replace as necessary. The o-ring is located on the
underside of the cover in the upper opening.
Re-assembly
• Replace the guide tube (20) over the impeller shaft.
• Replace the hydrometer cover (24) onto the body.
• Replace the cover hex bolts (12) along with their washers (14) and nuts (61).
• Tighten the nuts.
DIAPHRAGM SUB-ASSEMBLY
Removal of Diaphragm Assembly
• Remove all eight screws from the inner circle of screws on the lower diaphragm disc
(25). Four of the screws are ½” length (21) and four are 7 ∕
8
” length (24).
• Insert the four 7 ∕
8
” screws (24) into the holes from which you removed the four ½”
(21) screws and tighten. This will lift the entire diaphragm subassembly off of the stem
subassembly.
• Pull the diaphragm subassembly up and remove it from the hydrometer body.
• Inspect the diaphragm (23) for cracks or excessive wear. Continue with the following
steps to replace the diaphragm only if necessary.