INSTALLED on the outflow port of the Valve Body ( or in meter assemblies ), and I've seen them pointed both in or out.
It should be ( will work best ) if pointed outward ( nozzle pointed towards the impeller of the meter ).
Theï¿½PURPOSEï¿½of the flow straightener is to help the meter turbine / impeller "Move" when the water flow rate is low.
Straightening the flow = concentrating the flow.
The system will "work" without a straightener, but will not be as accurate ( counts all the water used at lower flow rates ).