A pitot tube is considered to be an economical alternative to an orifice plate. Accuracy of a pitot tube varies from 0.5% to 5% FS, which is almost equivalent to that of an orifice meter. The flow rangeability of a pitot tube which is 3:1 (in a few cases it is 4:1) is also analogous to the competence of an orifice plate.
An orifice meter used to measure the full flowstream whereas the pitot tube generally detects the liquid flow velocity at only a single point in the cross-section of a flowstream. This is the major point of distinction between the two types of flowmeters.
An extra advantage offered by a slender designed pitot tube is that it can be inserted into existing and pressurized pipelines (usually referred to as hot-tapping) exclusive of any shutdown.