Typical stand-pipe installation with 2" coupling. When to Use a Stand-Pipe? Foam and vapor absorb ultrasonic energy, and turbulence deflects it. For robust measurement in applications with surface foam, turbulence or vapor, simply install your Flowline ultrasonic level sensor in a stand-pipe. Stand-pipe installations isolate surface foam, eliminate turbulence and minimize vapor at the sensor's point of measurement. The basic stand-pipe assembly includes a pipe & female threaded adapter. The pipe must run the entire measurement span in length with no couplings or holes. It's that easy. For complete instructions on installing your sensor in a stand-pipe, click here.