Non-Conductive Or Insulated Pipeline - ABB K-MAG 10D1476 Instruction Manual

10D1476 K-MAG MAGNETIC FLOWMETER INSTRUCTION MANUAL

2.4.3 Non-Conductive or Insulated Pipeline

For the magnetic flowmeter mounted in a non-conductive or liquid insulated pipeline (such as totally
plastic pipe, ceramic lined iron pipe, or cast pipe with internal bitumastic coating), perform the
grounding procedure outlined below. Refer to Figures 2-11 and 2-12 to supplement this discussion.
1. Grounding rings are mounted between
the meter, and the upstream and down-
stream pipe flanges. These metal ground-
i n g r i n g s a r e a v a i l a b l e i n v a r i o u s
corrosion resistant materials and should
be selected to be compatible with the
process liquid. When installed, these
rings are centered by the flange bolts and
therefore must be selected according to
the flange rating. If grounding rings were
not specified when the meter was or-
dered, refer to Section 7.0 Tables 7-2 and
7-3 for ordering information. Refer to Fig-
ure 2-10 for the outline dimensions of the
grounding rings.
2. When installing the meter in the pipe-
line, place a grounding ring at both the
inlet and outlet connections of the mag-
netic flowmeter. Provide gasketing be-
tween the face of the meter (see Figure
2-12) and the grounding ring and between
the grounding ring and the adjacent pipe
flange; i.e., four gaskets required. (Note
that the gasket at the meter face must fit
inside the end ring.) Position the ground-
ing rings in the pipeline so that the meter
grounding straps (2) attached to the me-
ter ground post will easily reach the
ground strap connection bolt on the re-
spective grounding ring.
3. The user must supply two bonding wires which will connect the flanges adjacent to the
meter to the meter grounding rings. These should be made with ring lugs and #12 AWG,
or heavier, copper wire. They should be secured, along with the free end of each stainless
steel bonding strap from the meter, to the upstream and downstream grounding rings,
using 1/4" hex head bolts and external tooth lockwashers (supplied with the grounding
rings when the rings are supplied by the manufacturer).
4. The flanges adjacent to the meter must be drilled and tapped for 1/4" threads. A bright
metal surface around the area of the tapped hole must be obtained using a file or emery
cloth. The bonding wires from the grounding rings are to be attached to the flanges with
1/4" bolts and external tooth lockwashers.
5. The user must supply a sufficient length of wire for connecting the meter grounding
post (ring lug supplied) to a good electrical ground. (Number 12 AWG, or heavier, copper
wire may be used for this grounding wire.)
FIGURE 2-10. OUTLINE DIMENSIONS,
GROUNDING RINGS*
* F o r a p p l i c a t i o n s o t h e r t h a n A N S I
CLASS150, contact the manufacturer.
2-15