A powerful fan system moves air past the object; the fan must have straightening vanes
to smooth the airflow.
Additionally, content was added for launchers and receivers, strainers, orifice plates, straightening vanes
, valve extensions and operators, and various coatings, linings, and weightings.
These special lances are designed to negotiate the internal straightening vanes
all the way to the orifice plate (measuring device) at the meter's center.
Tube bundle straightening vanes have been around for a long time.
These options were the choice whether to use straightening vanes or not.
This can be accomplished by using straightening vanes
and filters/strainers in the upstream piping.
Also included on the meter run were the temperature and pressure transmitters, a strainer with Dp switch, straightening vanes
, an on-line meter lubricator, a load-limiting orifice and a welded double-valve bypass.
Straightening vanes are to be set ahead of five nominal pipe diameters upstream of the meter inlet.
For those meters having internal straightening vanes, swirl direction at the rotor inlet can be different from swift direction at the meter inlet.
Sources of jetting include a partially-open valve, a closed upstream regulator, a partially blocked strainer or filter, or an obstruction at the meter inlet or upstream straightening vanes.