KROHNE CORIMASS G-MFM 4085 EN - Manual (Page 10)

10
1.2.6 Cross talk
Multiple instruments of the same size installed in the same structure may cause a problem with
cross talk between the operating frequencies of the instruments.
If this type of installation is envisaged, please contact your nearest Krohne office or
representative for assistance.
Instruments of different sizes are normally not a problem. As a guide the following table of
frequencies are provided for information ( +/- 5 Hz ) :
10 G+ 100 G+ 300 G+ 800 G+ 1500 G+ 3000 G+
Frequency in air (Hz) 230 223 253 250 290 295
Frequency in Water (Hz) 224 203 219 194 205 210
1.2.7 Inner Pipe diameters of the G-Series
Inner Diameter 10 G+ 100 G+ 300 G+ 800 G+ 1500 G+ 3000 G+
[mm] 4.93 14.46 23.58 37.60 47.96 68
[inch] 0.19 0.57 0.93 1.48 1.89 2.68
Tube thickness [mm] 0.71 0.71 0.91 1.20 1.42 2.00
1.2.8 Sanitary Connections
The installation guidelines are the same for sanitary connections as for flanges up to the
300 G.
The 800 G, 1500 and 3000 G has a different requirement due to the weight of the meter. The
standard sanitary connectors are not capable of carrying the weight of the meter. As a safety
precaution Krohne has decided to ship the 800 G to 3000 G with extended spool pieces with the
customer-requested sanitary connectors on the ends.
The installation length is thus increased with this extra set of spool pieces. This has the
advantage of having the correct length and outside diameter of the pipe to enable secure
clamping and a vastly improved installation. Supports must be used on the extra spool piece
close to the sanitary connection.
All G+ meters with sanitary connections have stainless steel adaptor, which screw on each end
of the meter using seals between the adaptor and the meter. The standard seal material is
PTFE on 10 G+ and 100 G+, and Viton for all other sizes. Other materials are available on
request. It is important that the adaptors are properly tightened to ensure crevice free seal (see
table on the next page for correct torque tightening valves.