Questions regarding the measurement of pressure vessel wall thickness?
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While chatting with a colleague today, I was asked about a question regarding the measurement of wall thickness in pressure vessels and pipes. I’d like to discuss this in the following areas: 1. Are there any measurement standards? 2. Measurement methods: Nowadays, ultrasound is often used for measurement, as well as mechanical methods. Are there any other specific methods? 3. Measurement values: What range is considered acceptable? Within the negative tolerance range for plate thickness? Or something else? 4. Measurement location: Which area should be selected for measurement? Gas and liquid phase erosion areas? Stress concentration area? Corrosion-prone areas? 5. Number of measurement points: How many points need to be measured? 6. Rework after measurement? That’s about all I can think of for now. I hope more friends will join in the discussion; thank you!
Hasn’t anyone done it before? A friend who has done this before can help reply, thank you.
I’m not sure if you’re referring to newly manufactured or used pressure vessels; in the case of newly manufactured ones, it’s necessary to measure the thickness of the material used during production. For old pressure vessels, a thickness gauge can be used for measurement; generally, the areas with more severe corrosion are inspected, with 5–10 points measured to determine the minimum thickness. If the thickness is below the specified value, the affected area must be repaired or replaced, and flaw detection is carried out after welding is complete. Hydraulic testing, etc.
Measurements are taken using a thickness gauge; generally, at the bends in pipes and in areas of containers that are prone to corrosion, the negative deviation of the steel plate thickness usually does not exceed 5% in terms of absolute value, although this figure can vary depending on the thickness.
Thank you to the two people above; I hope more friends will join the discussion!