ABB CK-MAG 10D1477 Instruction Manual page 23

10D1477 MAGNETIC FLOWMETER INSTRUCTION MANUAL
The CK-MAG magnetic flowmeter is supplied in one of two basic body designs, depending upon
meter size. For example, 25 - 40 mm (1 - 1-1/2 inch) size meters have clearance holes provided in
the meter body for through-bolt mounting, while 50 - 100 mm ( 2 - 4 inch) size meter bodies mount in
a cradle formed by the mounting studs and sleeves used for that particular 4-bolt or 8-bolt flange
pattern. Typical mounting arrangements are illustrated in Figures 2-7 and 2-8. Figure 2-9 illustrates
the use of sanitary end fittings (flanged adapter with ferrule). Line schedule 80 or lighter pipe is
recommended for system piping.
Installation of the CK-Mag magnetic flowmeter must provide a minimum of five pipe diameters of
conductive exterior pipeline (may be lined with insulating material) on each side of the meter. This
must be done to prevent stray electrical interference from coupling to the interior of the meter and
producing unacceptable zero offsets.
When placed in a lined pipeline, a pair of meter grounding rings is required (discussed under Section
2.4) to facilitate grounding of the process. Good grounding is effected by bonding to the process
liquid, both upstream and downstream of the meter, thereby preventing any stray electrical currents
that may be carried by the pipeline, or by the process, from passing through the magnetic flowmeter.
Improper grounding often results in unsatisfactory meter performance, therefore particular attention
should be paid to the meter grounding procedure.
The flange gaskets supplied with the installation kit are the proper size for the particular meter. These
gaskets fit inside the meter housing end rings, against the upstream and downstream spool faces, as
shown in Figures 2-7 and 2-8. When the meter is installed, the gaskets must be placed within the
housing end rings so that they will be between the spool face and the adjacent pipe flange. When
sanitary couplings are specified, the flanged adapters with the ferrule for Tri-Clamp coupling are
preassembled to the meter body (see Figure 2-8). Raised face type flanges are recommended for
meters with sanitary couplings.
When the CK-MAG is used in areas where the incidence of radio frequency transmission and
resulting interference (RFI) is known to be high, special metallic gaskets must be installed. These will
prevent the RFI generated by devices such as portable radio transceivers from entering the meter
bore, where it will generate unacceptable noise levels. These gaskets must be placed in contact with
either a grounded metallic pipeline or meter grounding rings, as previously discussed.
If special metallic gaskets were not specified when the meter was ordered or replacement gaskets
are required, refer to Section 7.0 Table 7-4 for ordering information.
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