Weir Plate / Nozzle Body

The weir plate or nozzle body is a critical flow-regulating element used in overflow weirs and nozzle systems. It defines the geometry and dimensions of the opening through which fluid passes, directly controlling flow rate, discharge pattern, and hydraulic characteristics. In a weir, it is the plate over which liquid flows; in a nozzle, it is the body that shapes and accelerates the fluid jet. This component is typically manufactured from materials such as stainless steel (e.g., 304, 316), carbon steel, specialty alloys, or engineering plastics like PTFE and PVDF, depending on the application and media compatibility. Key parameters include nominal diameter (DN15–DN600 per ISO 6708), face-to-face length (130–850 mm per ISO 5752), operating pressure (1.0–1.6 MPa), operating temperature (-40 to 85 °C), flow coefficient (20–1200 m³/h per ISO 5167), leakage rate (0.01–0.1%), surface roughness (Ra 0.8–3.2 µm per ISO 1302), material grade (304/316L per ASTM A240), hardness (150–220 HB per ISO 6506), and weight (5–150 kg). These values are reference ranges for directory purposes and must be confirmed for the specific model and application. The component operates by presenting a specific geometric profile to the fluid stream, and its performance is governed by the weir equation or orifice flow equations. Proper selection requires consideration of fluid properties, flow rate, pressure, temperature, and installation dimensions. Verification of standards and compliance should be done with the legal manufacturer or supplier. Maintenance signals include wear, erosion, or deformation of the flow surface, which can affect accuracy and efficiency. Failure boundaries include excessive pressure or temperature, which may cause structural damage or leakage.

The weir plate or nozzle body operates by presenting a specific geometric profile (e.g., sharp-crested, broad-crested, or a shaped orifice) to the fluid stream. The fluid's head (pressure or elevation) causes it to flow over the weir plate or through the nozzle body. The flow rate is governed by the geometry of this component (e.g., crest length for a weir, orifice diameter and shape for a nozzle) and the upstream fluid conditions, following principles like the weir equation or orifice flow equations. The component's dimensions and surface finish directly influence the discharge coefficient and flow characteristics. Proper installation and alignment are essential to achieve the designed performance.