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What This Guide Helps With
Troubleshooting unexpected safety-valve discharge caused by overpressure, contamination, improper venting, unstable control, or a defective pressure-relief assembly.
Step-by-Step Troubleshooting
1. Protect Personnel From Steam Release
A safety valve may discharge hot steam without warning. Keep personnel clear of the valve outlet and door. Stop clinical use. Quarantine the load. Allow the chamber to cool and depressurize. Do not cap, block, adjust, or hold the valve closed.
Expected outcome: Personnel are protected and the pressure-relief path remains unobstructed.
2. Confirm the Reported Valve Behavior
Determine whether the valve:
- Drips when the unit is cold.
- Hisses continuously during heat-up.
- Releases steam before normal pressure is reached.
- Opens only when pressure appears excessive.
- Chatters or cycles repeatedly.
- Leaks after the cycle is complete.
- Was mistaken for normal exhaust discharge.
Expected outcome: The actual leak location and timing are identified.
3. Verify the Source of the Leak
After the sterilizer is cool:
- Inspect visually without disassembly.
- Distinguish the safety-valve area from the door gasket, exhaust tubing, and drain connections.
- Look for water tracks, mineral deposits, or staining.
- Do not touch or manipulate the valve while hot.
Expected outcome: The discharge is confirmed to originate from the safety-valve area.
4. Check Cycle Selection and Loading
Confirm that:
- The approved cycle was selected.
- The chamber was not overloaded.
- Packs did not block accessible chamber openings.
- The load type matched the cycle.
- No unauthorized settings were changed.
Expected outcome: Incorrect cycle selection or loading is ruled out. If correction prevents further discharge and testing passes, stop troubleshooting.
5. Inspect Drain and Exhaust Paths
Restricted exhaust can contribute to abnormal pressure behavior. Check accessible tubing for:
- Kinks.
- Pinching.
- Blockage.
- A full waste container.
- A submerged outlet.
- A backed-up facility drain.
Expected outcome: Drain and exhaust paths are open. If correcting a restriction resolves the valve release, stop troubleshooting.
6. Check the Pressure Indication
During a controlled test only when safe:
- Observe whether the displayed pressure rises smoothly.
- Compare the valve release timing with the displayed pressure.
- Stop the cycle if pressure appears uncontrolled.
- Do not assume the valve is defective when overpressure may be present.
Expected outcome: The relationship between displayed pressure and valve release is documented.
7. Inspect for External Contamination
With the unit cool:
- Look for mineral deposits or residue around the valve outlet.
- Check for contamination caused by water quality.
- Verify the reservoir contains the approved water.
- Do not scrape, lubricate, adjust, or disassemble the valve.
Expected outcome: External contamination is documented without altering the safety device.
8. Perform an Approved Pressure Verification
Qualified personnel may verify pressure behavior using approved test equipment and manufacturer procedures. Do not adjust the safety valve in the field unless explicitly authorized. Do not repeatedly trigger the valve for testing. Stop testing if pressure control is unstable.
Expected outcome: Pressure and valve behavior are confirmed as safe or the unit is removed from service.
9. Complete a Controlled Functional Cycle
Only when an external cause was corrected and no unsafe condition remains:
- Run the approved test cycle.
- Observe pressure rise and hold.
- Confirm no premature release occurs.
- Verify normal exhaust.
- Complete required sterilization-quality testing.
Expected outcome: The safety valve remains closed during normal operation and the cycle completes safely. Troubleshooting can stop.
10. Remove From Service for Any Continued Valve Leakage
Remove the sterilizer from service when:
- The safety valve leaks while cold.
- Steam releases prematurely.
- Pressure appears excessive.
- The valve chatters or repeatedly opens.
- The valve outlet is damaged.
- The pressure indication cannot be trusted.
Expected outcome: A questionable pressure-relief system is not used clinically.
If the Problem Persists
External loading, cycle selection, water quality, and exhaust restrictions have been ruled out. Remaining categories may include the safety valve itself, heater control, pressure or temperature sensing, vent control, mineral buildup, calibration, or internal pressure-control circuitry. The sterilizer should be:
- Removed from service.
- Labeled Out of Service.
- Sent for repair or bench evaluation.
- Evaluated using appropriate Tuttnauer documentation and approved pressure test equipment.
- Repaired, replaced, calibrated, or adjusted only by qualified personnel.
- Return to service requires documented verification of pressure control, safety-valve performance, complete cycle operation, and sterilization-quality testing. Knowing when to stop external troubleshooting is proper troubleshooting.
Clinical Use Tip
Never obstruct a leaking safety valve; remove the sterilizer from service and keep personnel clear of the discharge path.
Work Order Documentation (CCR Method)
CCR = Complaint, Cause, Resolution
Complaint
What was reported by the clinical staff.
Example:
"Sterile Processing reported steam releasing from the safety-valve area before the cycle reached sterilization."
Cause
What was observed during troubleshooting.
Example:
"Clinical Engineering found the exhaust hose obstructed by a full collection container, causing abnormal pressure behavior."
Resolution
What action was taken.
Example:
"Emptied the container, corrected the hose position, completed an approved cycle without valve release, and returned the sterilizer after pressure and quality checks passed."
Helpful Details to Include (If Known)
- Leak or discharge location.
- Cold leak or cycle-only release.
- Cycle phase at release.
- Displayed pressure.
- Valve chattering or continuous hissing.
- Drain and exhaust condition.
- Water type and visible scale.
- Load type and arrangement.
- Pressure-verification result.
- Full-cycle result.
- Final quality-control results.
- Final device status.
Final Thought
A safety-valve concern is a pressure-safety issue, not a nuisance leak. Verify the discharge source, cycle, loading, exhaust path, water quality, and pressure behavior without adjusting the valve, then escalate any continued release. That is successful troubleshooting.