ModMAG M1000 - Straight Pipe Requirements; Minimum Straight Pipe Lengths; Pipe Reducer Requirements; Custom Reducer Slope Angle

Straight Pipe Requirements
Sufficient straight-pipe runs are required at the
detector inlet and outlet for optimum meter accuracy
and performance. An equivalent of three diameters of
straight pipe is required on the inlet (upstream) side. Two
diameters are required on the outlet (downstream) side.
FORWARD FLOW
MINIMUM STRAIGHT PIPE
MINIMUM STRAIGHT PIPE
ELBOW
TEE
GATE VALVE
(FULLY OPEN)
MINIMUM STRAIGHT PIPE
CHECK VALVE
GLOBE VALVE
BUTTERFL
Y VALVE
PUMP
ELBOW
TEE
ANY VAL
VE
FLOWMETER
3 x D
7 x D
2 x D
D (Pipe Size) D (Pipe Size)
MINIMUM PIPING REQUIREMENT
STANDARD CONCENTRIC
REDUCERS
(NO DISTANCE REQUIRED)
Figure 12: Straight pipe requirements
Pipe Reducer Requirements
With pipe reducers, a smaller meter can be mounted in larger pipelines. This
arrangement may increase low-flow accuracy.
There are no special requirements for standard, concentric pipe reducers.
Custom fabricated pipe reducers must have an approximate slope angle of
8degrees to minimize flow disturbances and excessive loss of head. If this is not
possible, install the custom pipe reducers as if they were fittings and install the
required amount of straight pipe.
Figure 13: Pipe reducer requirements
You can determine the occurring pressure drop by using the shown nomogram
(only applicable to liquids with similar viscosity like water).
OTE: N In cases where flow velocities are very low, you can increment them by
reducing the size on the measuring point and hence obtain a better
measuring accuracy.
Define pressure loss:
1. Calculate diameter ratio d/D.
2. Read pressure loss depending on d/D ratio and ow velocity.
Diameter Ratio d/D
Pressure Drop in mbar
Figure 14: Pressure drop nomogram
ModMAG® M1000 Electromagnetic Flow Meter
Page 12 March 2020MAG-UM-00379-EN-07