ASME MFC-12M pdf download Measurement of Fluid Flow in Closed Conduits Using Multiport Averaging Pitot Primary Elements 4 OPERATING PRINCIPLES 4.1 Description of Operation The multiport averaging Pitot primary flow element or averaging Pitot tube (APT) is similar to the conven- tional single point Pitot tube in operation, but differs in construction. It is typically designed as a strut, or...