Published 24 July 2026 · 6 min read · Case Study
Customer identity confidential. Component shown is a generic engineering representation, not the customer’s drawing.
1. The Component
A generic engineering representation of the component family — an aluminium HPDC valve housing with a threaded process port and a machined, pressure-critical bore.
Pressure Critical Feature
Ø43 +0.05 / 0 mm
2. Failure Mechanism
Machining exposes subsurface gas porosity
Pressure leakage
Rejected component
3. Root Cause Analysis
Metal Flow
Gas Entrapment
Insufficient Overflow
Poor Venting
Localized Porosity
Leak Test Failure
Root Cause
Localized gas entrapment around the machined pressure cavity — not random casting porosity.
4. SAPL Engineering Improvements
Tooling
- Gate redesign
- Runner balancing
- Overflow relocation
- Vent optimisation
Metal Flow
Before
After
Process
- Controlled injection profile
- Melt temperature optimisation
- Stable process window
Validation & Assurance
- Dimensional & machining inspection
- Air leak & pressure testing
- Repeatability across trials
- PPAP-level documentation
5. Metal Flow Simulation (Conceptual)
Before Optimisation
- • Turbulent, high-velocity flow
- • Air entrapment at cavity corners
- • Higher risk of porosity
After Optimisation
- • Laminar, directional flow
- • Efficient gas evacuation
- • Minimal porosity risk
6. Engineering Timeline
Problem Identified
Failure Mapping
Tool Review
Metal Flow Analysis
Tool Modification
Production Trial
Leak Validation
Production Approval
7. Results
Pressure Leakage
Controlled
Leakage eliminated in validated production
Machining Scrap
Reduced
Significant reduction in machining rejects
Production Stability
Improved
Consistent, repeatable process capability
Pressure Test Performance
Stable & Repeatable
Consistently meets customer pressure test requirements
Pressure-tight die castings are not achieved through machine parameter optimisation alone. Stable production begins with intelligent tooling design and controlled metal flow.— SAPL Engineering
Engineered • Validated • Manufactured
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