2-4
IM 01F06A00-01E
2. INSTALLATION
• Piping for Avoiding Bubbles
Flows containing both gas and liquid cause problems.
Avoid gas bubbles in a liquid flow. Piping should be
carried out to avoid bubble generation.
Install the valve on the downstream side of the flowme-
ter because pressure drop across the control valve may
cause gas to come out of the solution.
F020303.EPS
Flow
Flow
Flow
(Good)
(Good)
(No Good)
Control
Value
Figure 2.4
(3) Multi-Phase Flow
digitalYEWFLO can measure gas, liquid and steam
when there is no change in state. However, accurate
measurement of mixed flows (e.g. gas and liquid) is not
possible.
F020304.EPS
(No Good)
(No Good)
Mist flow
(No Good)
Stratified flow
Bubble flow
Liquid
Flow
Gas Flow
Figure 2.5
2.3 Precautions Regarding In-
stallation
WARNING
In case of high process temperature, care should be
taken not to burn yourself because the surface of
body and case reach a high temperature.
(1) Gas or Steam Measuring Precautions
• Piping to Prevent Standing Liquid
Mount digitalYEWFLO in a vertical pipeline to avoid
liquid traps. When digitalYEWFLO is installed horizon-
tally, raise that part of the pipeline in which the
digitalYEWFLO is installed.
F020301.EPS
(Good)
(Good)
(No Good)
Flow
Flow
Flow
Figure 2.2
(2) Liquid Measurement Precautions
To insure accurate measurement, the digitalYEWFLO
must always have a full pipe.
• Piping Requirements for Proper Operation
Allow the flow to flow against gravity. When the flow is
moving with gravity, lift the down-stream pipe length
above the digitalYEWFLO installation level to maintain
full pipeline.
Flow
Flow
Flow
Flow
(No Good)
(No Good)
(Good)
(Good)
h h>0
h
h>0
F020302.EPS
Figure 2.3
