Required Lengths of Straight Runs
Flow altering devices such as elbows, valves, and reducers can affect accuracy. See the diagram below for typical flow meter system installation.
The recommended guidelines are given to enhance accuracy and maximize performance. The distance given here are minimum requirements; double them for desired straight pipe lengths.
- Upstream: allow a minimum straight pipe length at least 10 times the internal diameter of the pipe. For example, with the 50mm pipe, there should be 500mm of straight pipe immediately upstream. The desired upstream straight pipe length is 1000mm.
- Downstream: allow a minimum straight pipe length at least 5 times the internal diameter of the pipe. For example, with the 50mm pipe, there should be 250mm of straight pipe immediately upstream. The desired upstream straight pipe length is 500mm.