Long radius nozzles are used as flow elements for flow measurement of aggressive and non-aggressive gases, steam and liquids.
Long radius nozzles consist of a rounded inlet section and a cylindrical throat. The rounded inlet section has the shape of a quarter ellipse. The pressure tappings are situated in the pipe at 1D in front of and 0,5D behind the nozzle (D=pipe inner diameter). Usually, they are manufactured on site. This long radius nozzle type is designed to be mountable between flanges.
The ISA 1932 Nozzle is used for high velocity, non-viscous, erosive flows which would wear or damage an orifice plate. Typically nozzles have a larg capacity and well accuracy with high velocity flows.The required straight inlet section is much less than an orifice and the discharge coefficient of the nozzle is such that a nozzle can measure approximately 55% higher flow rates than an orifice plate with a similar beta ratio and design differential pressure. ISA 1932 Nozzles have a smooth centrical inlet leading to a throat section with sharp outlet. The length of the ISA Nozzle depends on the Beta-Ratio. The lower the ratio the less the length. The ISA 1932 Nozzle can also be clamped between flanges (within the bolt circle). Also the opportunity of a complete meterrun with a weld-in ISA 1932 Nozzle is possible. All design alternatives can be achieved with annular-chambers.