#Product Trends
Testing Fire Extinguisher Shell Linings
A brief introduction
Background
Fire extinguishers are vital safety devices that need to function reliably in emergency situations. The integrity of their shell linings is crucial for their continued effectiveness. Compromised linings will lead to failure, specifically, corrosion of the fire extinguisher body, which may leak as a result, and which in any case will require replacement.
To ensure that fire extinguishers are free from defects that could impair their lifetime, advanced testing methods are employed. One such method is high voltage holiday detection, specifically using the Buckleys mains-powered Lab Pro2 pinhole detector. This case study explores the application of this technology in testing fire extinguisher linings.
Objective
To demonstrate the application and effectiveness of the Buckleys Lab Pro2 high voltage holiday detector with a carbon-coated brush electrode for assessing the integrity of fire extinguisher shell linings.
Equipment overview
The Buckleys Lab Pro2 Pinhole Detector: A high voltage DC pinhole detector designed for rapid and effective testing of non-conductive coatings and linings.
A Carbon-coated drum brush electrode: Specifically designed for this application, it can easily be inserted through the neck of the extinguisher and expands to make reliable contact with the internal lining.
One or more extension rods may be used as required to enable access to the whole of the interior of the extinguisher tank.
Technical specifications of the Lab Pro2 pinhole detector
Mains supply voltage: 90-250V AC
Output voltage range: 0.9 kV - 40 kV, providing flexibility for different coating thicknesses and material types.
Sensitivity threshold range: 10 μA - 450 μA (factory-set to 200 μA for standard applications)
Meter accuracy: <10kV: +/- 10V. >=10kV +/- 100V
Built-in test standards: NACE SP0274, NACE SP0490, NACE SP0188, BSI BS EN60060, BSI BS EN14901, ASTM D5162-08, ASTM G62-07
Testing procedure
The fire extinguishers are decommissioned and depressurised for safety.
Setting up: The instrument is switched on and set to the appropriate settings and output voltage. (For detailed instructions, please click here)
Electrode insertion: The carbon-coated drum brush electrode is inserted through the neck of the extinguisher cylinder and expands naturally to contact the internal lining.
Voltage application: The voltage is applied to the electrode.
Fault detection: The electrode is swept over the internal surface of the lining. Faults are detected if a spark arcs from the electrode through the coating to the earthed shell, which triggers an alarm. The Lab Pro2 has a visual and audible alarm, ensuring a fault is never missed.
Analysis and reporting: detected faults are recorded, and the extinguisher is evaluated for necessary maintenance or replacement.
Technical insights
High Voltage application: The Lab Pro2's wide voltage range allows testing of various coating thicknesses and materials, ensuring thorough assessment of the lining's integrity.
Enhanced sensitivity: The sensitivity threshold and accuracy of the Lab Pro2 allow for the detection of even minor defects, crucial for maintaining the high standards of fire extinguisher performance.
Conclusion
The use of the Buckleys Lab Pro2 high voltage holiday detector, with its carbon-coated brush electrode, has proven to be an advanced and effective method for assessing the integrity of fire extinguisher shell linings. The combination of high voltage capability, precise sensitivity, and user-friendly design makes the Lab Pro2 an invaluable tool in ensuring the reliability and safety of fire extinguishers.
