Pipeline performance is central to mining operations. Whether transporting water, slurry, chemicals or compressed air, mining pipelines operate under high pressure and harsh environmental conditions. Proper pressure testing is therefore essential before these systems are energised — and AS/NZS 2885.5 outlines how field pressure testing should be carried out.
Below is a practical, step-by-step breakdown of how mining pipelines are tested and certified.
Step 1: Pre-Test Planning
Before any field testing begins, teams develop a testing plan which includes:
- Test pressures and durations
- Safety controls
- Permit requirements
- Isolation boundaries
- Equipment setup locations
Clear planning reduces risk and ensures compliance with site and regulatory requirements.
Step 2: Pipeline Preparation
The pipeline must be prepared by:
- Completing welding and NDT
- Cleaning or flushing the line
- Installing temporary test ends
- Ensuring supports are secure
- Removing air pockets for hydrotests
Any foreign material left in the pipeline can cause inaccurate results or damage equipment.
Step 3: Filling & Pressurisation
For hydrostatic testing, the line is filled with water and pressurised using calibrated pumps. The pressure is gradually increased following controlled steps to reduce risk and ensure stable readings.
Step 4: Stabilisation Phase
Once pressurised, the system is held at a predetermined test pressure. Technicians monitor:
- Pressure drops
- Temperature effects
- Leak indications
- Joint or weld issues
This proves the pipeline’s strength and integrity.
Step 5: Leak Testing & Inspection
While under pressure, technicians inspect accessible areas, including:
- Welds
- Flanges
- Valves
- Connected fittings
Any visible seepage or pressure drop is a sign of leakage requiring repair.
Step 6: Depressurisation & Draining
After testing, pressure is released slowly. The line is drained or dried depending on process requirements.
Step 7: Documentation & Certification
A complete test pack is produced containing:
- Test charts
- Calibration certificates
- Procedures
- Inspection reports
Mining operators rely on these documents for commissioning and regulatory audits.