Straight length of piping

The term "straight length of piping" is primarily used in metrology, i.e. when measuring flow rates by means of throttling devices (e.g. standard orifice, standard nozzle, standard Venturi tube).

As a rule, a straight length of piping must be available upstream and often also downstream of each pressure or velocity measurement point, if a defined measurement accuracy (see Measurement uncertainty) needs to be achieved.

A straight length of piping is also required upstream of the pump suction nozzle to ensure the centrifugal pump's operating behaviour is optimal.

This holds particularly true for pumps with a high specific speed (see Inlet conditions).