A flow straightener (or conditioner) may be necessary to stabilize a flow that would have crossed various fittings located upstream of the measuring element and close to it.
Required straight lengths (lengths without any fiitings or obstruction) on the upstream side of the differential pressure flow element are specified in the ISO5167 standard. These values must be observed to get an accurate flow measurement.
However, space restrictions can impose reducing upstream straight lengths. It is then necessary to install a flow conditioner.
All the characteristics of these devices are described in the ISO5167 standard.
OTHER PRODUCTS FLOW MEASUREMENT ACCESSORIES FROM DELTAFLUID