Spray Bar Flat-Fan Nozzle Set

Function

Each nozzle converts pressurised bitumen flow into a controlled fan pattern at a defined spray angle — typically 65° or 80°. Adjacent nozzle fans are engineered to overlap so that combined coverage uniformity is within ±5% across the mat width. Clogged, worn or incorrect-orifice nozzles immediately produce striping, over-dosing and under-dosing, which translate into surface texture defects and binder waste. Matching the orifice diameter to the target application rate and bitumen viscosity at working temperature is essential to achieving the specified L/m² without manual pump-speed correction mid-run.

Construction & quality

Bodies are precision-machined from 316L stainless steel, with chrome-nitride coated ductile iron available for high-abrasion applications. Orifice geometries are EDM-cut or sinker-eroded for dimensional accuracy within ±0.03 mm. Thread form is BSP 3/8" or NPT 3/8" to customer specification. The integral hex body allows torque application without body distortion. Nozzle seats are lapped to bubble-tight shutoff standard, preventing post-spray drip when the section valve closes. All nozzles in a set are orifice-matched and supplied as a numbered matched array to maintain overlap geometry.

When to replace

• Visible striping or skip patterns in the laid bitumen film after a run
• Uneven spray fan or post-pressure drip from individual nozzle positions
• Flow rate deviates more than 5% from target at constant pump pressure
• Physical orifice erosion or enlargement visible under lamp and loupe inspection
• Nozzle body thread weeps bitumen or cross-threads during routine removal