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MN01047
Issue/Rev. 0.0 (10/18)
Section III – Disassembly and Inspection
Caution: Disconnect power, isolate the meter and
relieve pressure before working on the meter.
Ensure that safety glasses and steel-toe safety shoes
are worn at all times during meter maintenance. Ensure
that appropriate gloves are worn during the dispensing
of sealants and lubricants. Prior to working on the
meter, drain the meter of all process fluids. If the meter is
in-line, it must be isolated and the internal pressure
must be zero.
Note:
It may be helpful to reference the parts list when servicing the
meter (see reference literature).
To drain the meter, rest the meter on its bottom so that
the Lifting Lugs are facing up. Remove the two Drain
Plugs (at the bottom of the cover). Carefully tip the meter
so that the fluid flows from the Housing.
If the meter is in-line, assure that upstream and down-
stream valves are isolated prior to removing the Drain
Plugs.
The following clearance tables are used to judge the degree
of wear of various parts of the meter. It is essential to
measure and record the clearances of the meter as
found when disassembled.
Maximum
Viscosity
20 cSt
20 cSt
Maximum
Temperature
150° F
65° C
Units
Inches
Millimeters
Rotor to Block
(.002)/(.003)
(.050)/(.070)
Rotor to Shelf
(.001)/(.003)
(.050)/(.070)
Blade to Slot
(.0015)/(.0035)
(.038)/(.080)
Blade Top End
Below Rotor
(.000)/(.002)
(.000)/(.050)
Blade Bearing to
Cam Radius
(.0005)/(.003)
(.012)/(.070)
Blade Tip to
Housing
(.002)/(.004)
(.050)/(.100)
Maximum
Viscosity
20 cSt
20 cSt
Maximum
Temperature
150° F
65° C
Units
Inches
Millimeters
Rotor to Block
(.003)/(.004)
(.070)/(.100)
Rotor to Shelf
(.002)/(.003)
(.050)/(.070)
Blade to Slot
(.002)/(.004)
(.050)/(.100)
Blade Top End
Below Rotor
(.000)/(.003)
(.000)/(.070)
Blade Bearing to
Cam Radius
(.0005)/(.003)
(.012)/(.070)
Blade Tip to
Housing
(.002)/(.004)
(.050)/(.100)
Table 4A – Allowable Clearances – 2" Meter
Table 4B – Allowable Clearances – 3" Meter
Disconnect the terminal block from the HRE. The Ter-
minal Block is a plug connection to the board. You can
pull the plug from the board to better access the screw
terminals to remove the wiring. Removing the board will
be easier if the wiring is pulled away from the Junction
Box. Inspect the board, looking for any electrical burn
marks that could indicate a malfunction.
Remove the four 3 mm hex-bit socket screws. This will
allow HRE Board removal from the meter (Figure 7).
Note:
Ground yourself from static discharge by keeping one hand on
the meter when handling the HRE Board.
Figure 7 – HRE Removal
Hex-Bit Socket Screws
Terminal Block
