Dynasonics MFX Series Insertion MagProbe Flow Meter - Manual (Page 30)

Rev. 01/11 -2.5- MFX
PROBE INSERTION
Before inserting the MagProbe into the piping system, it is
necessary to calculate the probe insertion depth that will place the
measuring electrodes at the proper position in the pipe. In order to
complete this calculation, some knowledge of the piping system
must be known. Refer to the paragraphs that follow and Figure 2.3
for information regarding this process. The variables required are:
x The overall probe length
x Pipe internal diameter
x Pipe wall thickness (including liners)
x The length of the valve stack
x Amount of straight pipe diameters in the system
Using this information and referring to Figure 2.3 proper insertion
depth can be determined.
Measurement A — the typical depth that the MagProbe tip is
inserted into the piping system is ǩ (12.5%) of the pipe internal
diameter. Assume ǩ of the pipe internal diameter unless a system
piping configuration does not have at least 15 pipe diameters of
straight pipe in the installation area.
Measurement B — Pipe wall thickness. This information can be
obtained from standard pipe wall charts (see the Appendix of this
manual) or ideally can be measured using an ultrasonic wall
thickness gauge. If the pipe is lined, include the liner thickness in
this measurement.
Measurement C — Measure the distance that is going to be taken
up by the pipe tap, nipple, full-flow ball valve and the insertion fitting.
NOTE: DMP1 through DMP6 probes utilize 1-½" NPT hardware.
The insertion fitting for the DMP1 through DMP6 probes is
approximately 2.5 inches long once completely torqued into
position.
Measurement E — This is the overall length of the probe measured
from the black measurement tip to the top flange on the probe.
Measurement D — This is the length of MagProbe that will be
protruding from the insertion fitting after it is inserted to the proper
depth in the fluid stream.
Step D -
Probe Insertion
Distances
PART 2 - MAGPROBE INSTALLATION