Yokogawa digitalYEWFLO (DY) - Manual (Page 13)

<3. INSTALLATION>
3-3
IM 01F06A00-01EN
Table 3.1 (b) Straight pipe length and recommendations (2)
D: Nominal diameter (mm)
Description Figure
Fluid vibration:
For a gas line which uses a position-type or roots-type blower
compressor or a high-pressure liquid line (about 1MPa or more)
which uses piston-type or plunger-type pump, fluid vibrations may
be produced.
In these case, install valve on the upstream side of digitalYEWFLO.
For inevitable fluid vibration, put a vibration damping device such
as throttling plate or expansion section in the upstream side of
digitalYEWFLO.
digitalYEWFLO
digitalYEWFLO
Piston-type or plunger pump:
Install the accumulator on the upstream side of digitalYEWFLO to
reduce fl uid vibrations.
digitalYEWFLO
Valve positon (T-type piping exist):
When pulsation causes by a T-type piping exist, install the valve on
the upstream of the fl owmeter.
Example: As shown in the figure, when the valve V1 is turned off,
the fluid flow throught B as to meter A the flow is zero. But due to
the pulsating pressure is detected, the meter is zero point become
fl uctuating. To avoid this, change the valve V1 location to V1'.
Note: In case of the Reduced Bore Type, moisture may be
remained upstream of the fl owmeter. Drain it appropriately.
Relocating
Valve (Off)
A
B
Flow
V1’ V1
digitalYEWFLO
Pressure and Temperature Taps:
Pressure tap outlet: install this tap between 2D and 7D on the
downstream side of a fl owmeter.
Temperature tap outlet: install this on the downstream side 1D to
2D away from a pressure tap.
Pressure tap
Temperature tap
Upstream
Flow
downstream
2 to 7D 1 to 2D
digitalYEWFLO
Mounting Gasket:
Avoid mounting gaskets which protrude into the pipe line. This may
cause inaccurate readings.
Use the gaskets with bolt holes, even if digitalYEWFLO is the wafer
type.
When using a spiral gasket (without bolt holes), confirm the size
with the gasket -manufacturer, as standard items may not be used
for certain fl ange ratings.
Pipeline Flange
Pipeline
No good
digitalYEWFLO