Yokogawa digitalYEWFLO (DY) - Manual (Page 12)

<3. INSTALLATION>
3-2
IM 01F06A00-01EN
Table 3.1 (a) Straight pipe length and recommendations (1)
D: Nominal diameter (mm)
Description Figure
Reducer pipe:
Ensure the upstream straight pipe length to be 5D or more, and the
downstream straight pipe length to be 5D or more for per reducer
pipe.
digitalYEWFLO
Flow
5D or more
Reducer
5D or more
Expander pipe:
Ensure the upstream straight pipe length to be 10D or more, and
the downstream straight pipe length to be 5D or more for per
expander pipe.
digitalYEWFLO
Flow
10D or more
Expander
5D or more
Bent pipe and straight pipe length:
1. Single bent pipe
2. Double bent pipe; coplanar
3. Double bent pipe; non coplanar
1.
2.
3.
digitalYEWFLO
Flow
10D or more 5D or more
digitalYEWFLO
Flow
10D or more 5D or more
digitalYEWFLO
Flow
20D or more 5D or more
Valve position and straight pipe length:
 Install the valve on the downstream side of the flowmeter.
The upstream straight pipe length dependent on the element
located on the upstream such as reducer/expander, bent and etc.,
refer to description as above. Keep 5D or more for downstream
straight pipe length.
 In case the valve has to be installed on the upstream of the
fl owmeter, ensure the upstream straight pipe length to be 20D or
more, and the downstream straight pipe length be 5D or more.
Refer to each element above for
straight pipe run.
digitalYEWFLO
Flow
digitalYEWFLO
Valve
5D or more 20D or more