Oval EX DELTA, EX DELTA-DIA, Руководство пользователя

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12
D-546-9-E
5. PIPING INSTRUCTIONS
For general considerations to be observed, see JIS Z 8766, “Flowrate
Measurement Methods with Vortex Flowmeters.”
5.1 Standard Piping Conditions
NOTE: A downstream straight pipe 5D or longer is required.
It is generally required that the flow pattern of a material moving into an inferential type meter be as uniform
as possible for precise metering. Accordingly, proper flow straightening measures must be taken when the
application engineer considers installation of a DELTA meter. In applications where OVAL straightening
devices (flow straightener, honey vane, and downstream pipe) are used, a straight pipe section is not required
unless otherwise specified. But if you plan to solve the flow pattern problem with a straight pipe section alone,
secure the length of a straight pipe conforming to the ISO standards given in Table 5.1 below, using a Sch. 40
pipe:
(1) OVAL flow straightener combined with downstream pipe (25mm and up in nom. dia.) D ＝ Nom. Dia.
No. Arrangement Remarks
1 Honey vane ⇒See Fig. 5.1 on page 12.
2
Flow
Straightener ⇒ See page 55 for face-to-face
dimension.
(2) Straight pipe alone without flow straightener
To match the meter diameter, use a Sch, 40 pipe for the straight pipe.
Table 5.1 Straight Pipe Lengths Recommended by ISO-5167 D ＝ Nom. Dia.
No. Arrangement Remarks
1 Reducer A concentric reducer is upstream of meter.
2 Elbow
An elbow is upstream of meter.
Two elbows are horizontally upstream of
meter.
Two elbows are vertically upstream of
meter.
3
Gate Valve
Fully Open
A full-open gate valve is upstream of meter.
4
Gate Valve,
Partially Open
A partially open gate valve, a narrow orifice,
or something that considerably disturbs the
flow pattern is upstream of meter.
➡ ➡
8D
Flow
Flow
Flow
Flow
Flow
Flow
Flow
Flow
12D
15D
23D
40D
50D
Partially open
Fully open
15D
25D