Inspection of the heater
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For the heaters used in the aqueous solution full-circulation urea production process, during normal operation steam condensate is usually analyzed to determine whether it contains ammonia. Therefore, when the system is shut down for maintenance, it is necessary to perform pressure testing on the steam entering each heater to check for leaks; what is the appropriate pressure level for such testing? Will such unilateral compression have an impact on the equipment? Welcome everyone to discuss.
Pressure testing is possible; the test pressure shall be in accordance with the product quality certificate.
This post was last edited by fjhuyuyang on 2012-3-24 09:04. If the steam condensate contains ammonia, a non-destructive inspection can be carried out first, after which it can be decided whether pressure testing is necessary based on the findings.
A comprehensive inspection must be carried out every six years. During regular major repairs, a hydrostatic test can be conducted. It is generally 1 times the design pressure. 25 times, or it can also be 1 times the working pressure. 25 times. Maintain the pressure at a minimum of 5–10 minutes, then reduce it to the operating pressure and inspect the container. Wait.
It is necessary to perform a pressure test for leak detection during major repairs. Normally, it is also possible to decide whether to apply water pressure during major repairs based on the analysis results. The suppression pressure is lower than the design pressure of each device. Pressuring indeed helps to identify problems. Implementation is recommended.
One more thing: inspection after suppression is crucial.
It is not recommended, and the reason is simple； Based on the management philosophy and operational principles of RBI, for risks that can be monitored and controlled, conducting strategy stress tests is at most an optional measure. Take a look; if you conduct a pressure test on one of the heaters in your company, how much work does that require? ； What other reasons can you give besides those explicitly specified by the regulations?
2. Comparison of inspection cycles: China – Annual inspections: once a year; Comprehensive inspections: determined based on the safety level (containers of grades 1 and 2 require inspections every 6 years, while those of grade 3 require inspections every 3 to 6 years). Pressure resistance tests: conducted every 2 inspection cycles. China’s inspection regulations set fairly fixed rules regarding inspection cycles; for pressure vessels, except in certain cases, any extension of the inspection cycle requires going through strict procedures. Moreover, China’s regulatory documents do not stipulate that online testing can replace internal testing. API: External inspection – to be carried out at least once every 5 years. Internal inspection and online inspection (where such online inspection refers to an online assessment that can replace internal inspection) – the inspection interval shall not exceed half of the remaining service life determined based on the corrosion rate, or 10 years. If the assessment indicates that its safe operating life is less than 4 years, the inspection interval shall be the remaining lifespan of its safe operation, with a maximum of 2 years. Pressure test — It is not mandatory, but pressure tests should be conducted when the test results indicate it is necessary, as well as on pressure vessels that have been repaired or modified. The API specifications are fairly flexible regarding inspection intervals; under certain conditions, online inspection can be used as a substitute for internal inspection, and the minimum inspection period required by the specifications can also be extended based on the results of risk assessment.