Baseline Systems BHM Series Hydrometer - Manual (Page 27)

Hydrometers Operation and Maintenance Manual •
27
Maintenance 1½” and 2” Models, Cont.
DIAPHRAGM/STEM DIS-ASSEMBLY
• Separate the base assembly from the cover (12).
• Visually inspect the diaphragm (37), valve cover (32) and stem
assembly (36) for damage or excessive wear. If replacement is
needed, continue with the following steps.
• Remove the six screws (39) from the diaphragm retaining ring (38).
• Lift the ring off of the diaphragm (37).
• Lift the diaphragm (37) off of the stem (36).
BASE AND STEM DIS-ASSEMBLY
• Place the base and stem assemblies upside down on a flat surface.
• Use the extraction tool to remove the valve cover (32) as follows:
- Slide the lower prongs of the extraction tool under the cover.
- Turn the bolt on the extraction tool clockwise until the
extractor seat fits securely into the stem.
- Continue turning the bolt until the valve cover slides off
of the stem (36).
• Invert the base and pull the stem (36) out of the base (33).
• Remove the base o-ring (23) from the underside of the base. Inspect
and replace as necessary.
• Remove the stem o-ring (34) from the groove in the hole in the
center of the base. Inspect and replace as necessary.
• Remove the diaphragm support ring (35) from the base (33).
• Inspect the base (33) for cracks or excessive wear. Replace as
necessary.
WARNING
You must use the extraction tool to remove the valve cover. Use
of any other tool may damage the valve cover and the stem.
Re-assembly
• Insert the diaphragm (37) into the grooves on the top of the stem
(36).
• Place the diaphragm retaining ring (38) over the diaphragm. Secure
the ring with the six screws (39). Apply Loctite 270 or similar glue
to the screws.
• Set the lower diaphragm support ring (35) inside the base (33).
• Insert the re-assembled diaphragm and stem assembly into the base.
• Push the valve cover (32) up onto the bottom of the diaphragm/stem
subassembly. It should easily snap into place.
• Remove and replace the central bushing o-ring (15) at the bottom of
the central bushing (14 not shown), located in the underside of the
cover (12).
• Set the cover (12) onto the re-assembled base subassembly. These
subassemblies are now ready for reinstallation onto the hydrometer
body.
Extraction Tool
Model Number:
00360-000072