Hydrant Flow Quick Disconnect Pitot Tube Kit (with Flow Nozzle). This Kit comes complete with Quick Disconnect Pitot tube with standard Blade, One Gauge with Rubber cover for protection and a. H-N501 Inspector’s Hydrant Flow Nozzle and stream straightener for more accurate reading from the Pitot Tube all fitted in a ABS waterproof ABS case. 2-1/2″ NST x 6″ NNI Flow Nozzle Model H-N25A straightens the stream of water at the hydrant port to get the most accurate pitot tube readings possible. This all-brass nozzle is nickel plated and. Has a 2 1/4 smooth bore ID tube delivering a constant. This kit will be furnished with a 2-1/2 liquid filled 0-160 PSI gauge. Gauges are dual read with Psi, kPa/Bar markings. Please specify if other range gauge or an extra gauge is required. Ble ranges are 60Psi 100Psi, 160Psi, 200Psi & 300Psi.