© 2021 VPInstruments | MAN-VP-VP38-EN | Revision: 2100 | Date: 25-01-2021
9
Piping table
The following table provides a guideline for proper distances between upstream or downstream
objects and the flow meter. The upstream length is the length between the last non-straight object
and the flow meter. If the upstream length is straight, and the distortion is downstream of the flow
meter, you can use the column "downstream length" as a guideline. In very complex situations, with
multiple up- and downstream objects, you should consider another location. This table is a practical
guideline and is not exact science. Practical situations can have multiple sources of distortion,
therefore VPInstruments does not take any responsibility for the correctness.
Picture
Description
Upstream
length
2
Downstream
length
2
Effect
Single elbow
30 * D
1
10 * D
1
Distorted flow profile
Complex feed-in
situation (header)
40 * D
1
10 * D
1
Flow profile will be
distorted
Double elbow, multiple
elbows following each
other
40 * D
1
10 * D
1
Distorted p
swirl
Diameter change from
small to large (gradual or
instant)
40 * D
1
5 *D
1
Jet shaped flow
Diameter change from
large to small (gradual
change, between 7 and
15 degrees)
10 * D
1
5 * D
1
Flattened flow profile
1 = inner diameter; 2 = minimum length
