SUGGESTED FLANGE BOLT TORQUE
Liner
Pipe Size
ft-lb
Nm
2”
18
25
3”
25
34
4”
20
27
6”
42
57
8”
65
88
10”
73
99
12”
97
132
Page 10
omega
.com
Equalization and Grounding
Metal Pipe Installations.
To equalize the electrical
potential of the fluid, the meter, and the surrounding
pipe, secure the flange plates (factory-installed on the
equalization wire) to both pipe flanges at one of the
bolt holes, as shown below. Be sure the lock washer fits
between the pipe flange and the flange plate. For the best
electrical bonding, remove rust and paint to expose clean,
bare metal where the equalization flange plate lock washer
contacts the pipe flange. Connection must be inspected
periodically for corrosion to maintain the necessary low
resistance connection.
Plastic Pipe and Electronically Noisy Installations.
When
installed in plastic pipe or in an electrically noisy system (near
a VFD etc.), grounding rings are recommended. As shown in
the diagram below, the equalization wires should be solidly
connected to the grounding ring tabs instead of the
flange
bolts as in metal piping installations. Where lightning
is a
threat, or in severe electrical environments, an optional
connection to a nearby equipment ground or ground rod may
be advisable.
WARNING: ELECTRICAL SHOCK HAZARD
When installed in a plastic piping system,
or when externally powered, the piping
system must be grounded to meet national
and local electrical safety codes. Failure to
do so can result in electrocution.
Equalization Lug
Meter
Flange
Pipe
Flange
Gasket
Pipe Flange
Flange Plate
Lockwasher
Metal Pipe
Metal Pipe
Meter Flange
Gaskets
Equalization Lug
Ground Clamp
(Exothermically weld when
corrosion is a concern)
8’ Ground Rod
Earth
Grounding Ring
Gaskets
Grounding Ring
Gaskets
#6, #8, or #12 AWG Stranded
Copper Ground Wire
Plastic
Pipe
Plastic
Pipe
INSTALLATION
Tightening Flange Bolts
NOTE: Mating pipe flanges must be ANSI 150# full face (FF)
and/or raised face (RF).
1.
Tighten flange bolts in an alternating pattern.
•
Tighten left flange bolt-1 to 20% recommended
torque.
•
Tighten right flange bolt-1 to 20% of
recommended torque.
• Repeat steps a and b for each bolt in an
alternating order, such as shown at right,
tightening to 40%, then 60%, then 80%, and
then 100%.
2.
Test for leaks.
3.
If needed, tighten further in 10% increments
until leaking stops.
DO NOT over-tighten.
Over-tightening can cause serious damage to
the flow
meter.
4.
Recheck after 24 hours, adjusting if needed.
Suggested Tightening Sequence
Caution:
Improper tightening sequence
can cause serious damage to the flow
meter.
•
Do not tighten one side at a time.
•
Do not tighten each bolt completely
at one time.
1
2
3
4
5
6
7
8
Grounding Ring Part Numbers:
2” = 104124 6” = 100877
3” = 102157 8” = 100878
4” = 100876 10” = 100879
12” = 103288
FMG470 Series
