The inspection cycle of pressure pipelines varies according to different materials, use conditions and safety status levels. Here are some basic guidelines:
Steel pipe: According to relevant laws and regulations, steel pipes need to be comprehensively inspected every five years under normal use.
Copper pipe: The characteristics of copper pipe determine that its annual inspection cycle is usually once a decade.
Plastic tube: The annual inspection cycle of plastic pipes is generally once every eight years.
composite pipe: The annual inspection cycle of composite pipe is generally once every seven years.
Full inspection cycle: The comprehensive inspection cycle of pressure pipelines is generally carried out at least once every six years. If the safety level of the pipeline is Class 2 or Class 1, the inspection period generally does not exceed six years; If it is Level 3, the testing period shall not exceed three years.
On-line inspection: Online inspection is carried out at least once a year, by the operators of the pipeline user unit, or an inspection and testing institution with corresponding qualifications can be entrusted.
Special cases: If one of the following conditions is met, the inspection period shall be appropriately shortened:
First inspection of the new pipeline after commissioning.
Class A and B pipes with corrosion rates greater than 0.25 mm/year.
Pipes that are likely to suffer local corrosion such as stress corrosion, pitting corrosion, etc.
Pipes that have the potential to develop fatigue (possibly subject to repeated stresses due to vibration, pulsating pressure, temperature cycling, etc.).
Long-distance pipeline: The inspection of long-distance pipelines includes annual inspection, comprehensive inspection and qualified use evaluation, of which the annual inspection is at least once a year.
Overall, the inspection cycle of pressure pipelines is affected by a variety of factors, including the material of the pipeline, the service environment, the operating status, and the safety status level. In practice, the inspection cycle may be adjusted according to the specific situation and the latest regulatory requirements. Regular inspection is crucial to ensure the safe operation of pressure pipelines.