What is hydrostatic testing?
Hydrostatic testing is a controlled pressure test that fills the extinguisher cylinder with water (not the agent) and pressurizes it to a level above its normal operating pressure. The test confirms the steel or aluminum shell can still safely contain its working charge — that years of corrosion, dents, or metal fatigue haven't compromised the cylinder. NFPA 10 mandates the test on a defined schedule for every type of portable extinguisher.
Hydrostatic test intervals (NFPA 10)
Every 5 years
- Stored-pressure water and water-mist extinguishers
- Wet chemical (Class K) extinguishers
- AFFF / FFFP foam extinguishers
- Carbon dioxide (CO₂) extinguishers
Every 12 years
- Stored-pressure dry chemical extinguishers (ABC, BC)
- Halon & clean-agent extinguishers
- Dry powder (Class D) extinguishers
The clock starts at the manufacture date stamped on the cylinder — not the date you bought it or first inspected it. We pull the date and tell you exactly when each unit is due.
What our hydrostatic testing service includes
- Verification of manufacture date and last hydro test date stamped on the cylinder
- Full discharge of agent and disassembly of valve, hose, and components
- External and internal inspection of the cylinder for corrosion, pitting, or damage
- Hydrostatic pressure test in a certified test bay to NFPA 10 / DOT specification
- Re-stamping of the cylinder with the new test date and our test facility ID
- Recharge with manufacturer-spec agent, new seal, new pin, and a fresh annual tag
- Updated maintenance record so you have a clean compliance trail
What happens if a cylinder fails the test?
Cylinders that fail hydrostatic testing — show pitting, leak, or expand beyond allowed limits — are condemned and destroyed. They cannot be returned to service under any circumstance. We'll quote you a replacement on the spot so your coverage stays intact.
How do I know if my extinguishers are due?
Check the small metal collar around the neck of each extinguisher — it's stamped with the manufacture date and any subsequent hydro test dates. If the most recent date is more than 5 years ago (for water/CO₂/Class K) or 12 years ago (for dry chemical), the unit is overdue.
Or, just call us. We'll do a free walkthrough of your property and tell you exactly which units need testing now and which can wait.
Schedule hydrostatic testing
Call 516-324-8078 or request a quote online. We can also enroll you in our reminder service so you never miss the next test date.