The Low-Pressure Leak Check
Phase 1: 10% of Operating Pressure
Submerge the manifold in a water tank or coat the exterior with soapy water. Apply very low pressure (approx. 5–10 PSI). Check for a steady stream of bubbles, which indicates a “path of least resistance” through the print layers or a slice-error in the manifold wall.
2
Hydrostatic Purge and Seal
Phase 2: Remove All Air
Fill the manifold completely with your test fluid (water or hydraulic oil). Ensure all air pockets are purged through the outlet before sealing it. Even a small bubble of trapped air can turn a structural failure into a dangerous “pop” rather than a simple crack.
3
The Proof Load
Phase 3: 1.5x Operating Pressure
Using a manual hydraulic pump, slowly increase the internal pressure to 1.5 times your intended working pressure. Hold this pressure for 15–30 minutes. Inspect for “weeping” (sweating of fluid through the walls) or visible bulging. If the pressure gauge drops even slightly, there is a structural leak.
| Observation | Result | Required Action |
| Visible Weeping | Fail | Increase wall loops in slicer or apply internal resin sealant. |
| Creaking/Cracking Sounds | Fail | Catastrophic failure imminent. Re-evaluate Z-axis orientation. |
| Pressure Drop > 2% | Fail | Check seals/fittings first. If seals are good, the part is porous. |
| Zero Leaks @ 15 min | Pass | Clean, dry, and clear for service. |