29/03/2026
Fire Extinguisher Hydro Testing Procedure
1. Pre-Inspection
Check extinguisher for:
Dents, corrosion, cracks
Damaged threads or valves
Verify:
Manufacturing date
Last hydro test date
Reject if severe damage is found
2. Depressurization & Discharge
Completely discharge the extinguisher
Ensure no residual pressure remains
Remove valve assembly carefully
3. Internal & External Cleaning
Clean inside using water or approved cleaning solution
Remove rust, scale, or residue
Dry thoroughly before testing
4. Filling with Water
Fill the cylinder completely with water
(Water is used because it is incompressible and safer than air)
5. Hydrostatic Pressure Testing
Connect cylinder to hydro testing machine
Apply test pressure (usually 1.5 times working pressure)
Typical Test Pressures:
CO₂ extinguisher: ~250 bar (as per standard)
Dry Chemical Powder: ~25–35 bar
Water/foam: ~20–25 bar
Hold pressure for 30 seconds to 1 minute
6. निरीक्षण (Inspection During Test)
Check for:
Leakage
Bulging (permanent deformation)
Pressure drop
👉 If any of the above occurs → FAIL
7. Pressure Release & Drying
Slowly release pressure
Drain water completely
Dry internally (using hot air or vacuum drying)
8. Reassembly
Refit valve, hose, and components
Replace defective parts if required
Refill with extinguishing agent
9. Marking & Certification
Stamp or label:
Hydro test date
Next due date
Issue test certificate
📅 Hydro Testing Frequency (General)
Water / Foam / DCP: Every 5 years
CO₂: Every 5 years
As per IS/NFPA or local regulations
