1. Preparation of equipment and personnel qualifications
Device compliance checks
Confirm that the testing equipment (e.g., hydrostatic testing machine, ultrasonic flaw detector) has passed the metrological certification, and the calibration is recorded within the validity period to ensure that the test accuracy meets the requirements of the national standard.
Check that the power supply, air source and hydraulic system of the equipment are in normal condition, and there is no leakage or pipeline blockage.
Operator qualifications
Operators are required to hold special equipment inspection qualification certificates and complete special training for CNG cylinder testing.
2. Confirm the status of the gas cylinder
Visual inspection of gas cylinders
Check whether there is bulging, denting, scratching or corrosion on the surface of the cylinder, and compare the damage level with the "Specification for Periodic Inspection of CNG Gas Cylinders for Vehicles" to confirm whether it meets the test conditions.
Check that the cylinder valves, connecting pipes, and seals are intact and free of leaks or looseness.
Residual pressure management of gas cylinders
Confirm that the remaining pressure in the cylinder ≤ 0.2MPa (if it is higher than this value, the pressure should be relieved first) to avoid the operation risk caused by high-pressure gas residue.
3. Preparation of testing environment
Ventilation and explosion protection requirements
The detection area shall be equipped with an explosion-proof ventilation system and an acetylene/methane concentration alarm device shall be installed, and the alarm threshold shall be set to 10% LEL.
Remove flammable and explosive materials at the testing site, demarcate warning areas and set up warning signs.
Security Device Configuration
Have fire extinguishers, explosion protection tools, and emergency sprinklers on hand to ensure a quick response in the event of an emergency.
4. Preparation of tools and consumables
Detection tool check
Equipped with a special wrench, pressure gauge, connecting hose and nitrogen replacement device, check that the tool is not aged or damaged.
Calibrate the gauge range (need to cover 0-30MPa) with an error of no more than ±1%.
Consumables presets
Prepare nitrogen cylinders for natural gas replacement in cylinders to ensure that nitrogen purity ≥ 99.9%.
5. Safety protection measures
Personal protective equipment
Operators need to wear anti-static clothing, protective masks, pressure-resistant gloves and anti-smashing shoes.
Confirmation of emergency procedures
Familiarize yourself with the leakage emergency response process in advance, including emergency pressure relief, personnel evacuation, and equipment isolation procedures.
