How to write the technical requirements for helium leak detection
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Both titanium and zirconium pressure vessels are now required to undergo helium leak testing. According to clause 3.2.13.4 of the Pressure Vessel Regulations, the vacuum level within the pressure vessel, the concentration of helium gas, the test pressure, the holding time, as well as the procedures for conducting the test must all be specified by the designer in the design documents. So, for pressure vessels with helium leak detection, how should the technical requirements specified in the drawings be formulated to meet the requirements of relevant regulations? Does anyone have a template available? Then, is a separate process document required for helium leak testing? Are there any reference templates available? Thank you so much:hug:
In the technical requirements of the design drawings, regarding the helium leak detection test, the following key parameters should be specified in detail to meet the requirements of relevant regulations: 1. **Vacuum level requirement**: It is necessary to specify the minimum vacuum level that must be achieved inside the pressure vessel during the helium leak detection test. 2. **Helium concentration**: Specify the helium concentration to be used during the test. 3. **Test pressure**: Specify the pressure that the pressure vessel should withstand during the test. 4. **Holding time**: The duration for which the pressure must be maintained after reaching the test pressure. 5. **Test Procedure**: Provide a detailed description of the specific steps for the helium leak detection test, including how to inject helium and how to locate the source of leaks. A template for drafting technical requirements can be as follows: [Helium leak detection test requirements] 1. Vacuum level: Before the test, the interior of the pressure vessel must be reduced to a vacuum level of not less than xx Pa. 2. Helium concentration: The helium concentration should be maintained at above xx%. 3. Test pressure: During testing, a pressure of not less than xx MPa should be applied. 4. Holding time: The holding time should be no less than xx minutes. 5. Operating procedure: Step 1: Evacuate the interior of the pressure vessel to the specified vacuum level. Step 2: Fill the container with helium at the specified concentration. Step 3: Apply pressure to the specified test pressure and maintain it for the prescribed time. Step 4: Perform leak detection using a helium mass spectrometer leak detector. Step 5: Record the test data and evaluate whether it meets the sealing standards. Process documents for helium leak detection do indeed need to be prepared separately to ensure the correctness and consistency of the operations. Process documents typically include detailed operating procedures, safety precautions, lists of equipment and tools, quality control points, etc. Although I don’t have ready-made templates available for download, you can use the technical requirement template provided above to develop specific process documents, or contact professional pressure vessel design and manufacturing firms for more detailed assistance and templates. .
Refer to NB/T47013.8 and HG/T20584