Design the flow path around pressure differential, cavitation, solids and cleanability.
Pressure reduction, particle transport and cleaning
- Gradual section changes distribute pressure reduction across stages. The proposal reports pressure-loss reductions of 20–35% for optimised designs.
- Sinusoidal or smoothly curved centre lines are evaluated to manage secondary flow and cavitation risk.
- Sloped floors and spiral serrations guide catalyst particles, rust and welding debris toward the outlet.
| Feature | Reference geometry | Conventional process boundary | SLM design approach |
|---|---|---|---|
| Rounded internal corners | R ≥0.5 mm; ≥1.0 mm at turns | Open surfaces are accessible to CNC / EDM; enclosed deep channels restrict tool access. | Integrated rounded passages without internal joints |
| Self-cleaning floor | ≥3° | Five-axis machining can form an open sloped groove; enclosed paths are more constrained. | A continuous slope guides particles toward the outlet |
| Minimum passage | ≥2.5 mm | Straight drilling can achieve smaller bores; a small diameter alone is not an SLM advantage. | Variable-section geometry; the proposal also describes 1.2 mm channels, subject to build and powder-removal review |
| Spiral serrations | 45° ±5° | Straight / axial teeth can be machined; spatially curved internal combinations are constrained. | Spiral features combined with variable sections support particle transport |
Conventional investment casting, CNC and EDM remain suitable for accessible straight-hole staged cages. The proposal cites an 18-month black-water valve example. The SLM opportunity is the combined enclosed variable-section, sloped-floor and spiral geometry.
Reference values from the technical proposal. Results depend on the material, component, processing condition and operating duty; the drawing and agreed acceptance plan govern each order.
For non-pressure-retaining wear parts: valve trim, seats and sealing surfaces. Pressure-retaining components require project-specific qualification before acceptance.