[Q&A Question 147] 2017.05.27
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This post was last edited by 955559 on 2017-7-21 at 22:51. [Q&A Question 147] May 27, 2017: What are the criteria for discarding furnace tubes? The reference answer can be seen after *replying*; points will be awarded for identifying the key points. (Unless otherwise specified, all questions and answers are based on hydrogenation units.) (1) Presence of bulges, cracks, or network-like cracks; (2) Severe corrosion; (3) Bending degree greater than 1.5–2 times the outer diameter of the furnace tube; (4) Outer diameter increased by 4–5% compared to the original value; (6) The expansion joint has been expanded repeatedly during use, exceeding the specified limits; (7) Corrosion or detachment of the expansion joint. Scoring criteria: 2 points for incorrect answers, 3–8 points for incomplete answers; 10 points for correct answers with detailed explanations, and 15–20 points if a correct answer is provided along with additional supplementary information. Please score according to these criteria. Note: If there are editing records after answering, only those who participated will be credited points. For continuous malicious spamming, 2 points will be deducted each time, with no upper limit. Pure numbers, pure emojis, or random letters unrelated to the answer are all considered malicious spamming; points will start to be deducted after three warnings. 2017 Q&A Summary Thread (updates starting now) http://bbs.hcbbs.com/thread-1657793-1-1.html 2017 Daily Question Summary Thread (updates starting now) http://bbs.hcbbs.com/thread-1657794-1-1.html 2016 Q&A Summary Thread (updates completed) http://bbs.hcbbs.com/thread-1597792-1-1.html
(1) There are bulges, cracks, or network-like cracks. (2) Severe corrosion. (3) The degree of bending is more than 1.5 times the outer diameter of the furnace tube. (4) The outer diameter is more than 4.5% larger than the original outer diameter. (6) The flared end requires repeated repairs during use.
1) Bubbling, cracks, or network-like cracks； 2) Severe corrosion and peeling ； 3) The curvature is 1.5–2 times greater than the outer diameter of the furnace tube ； 4) The wall thickness is less than the allowable calculated value ； 5) The outer diameter is 4-5% larger than the original outer diameter ； 6) During use of the expansion joint, repeated expansion operations are carried out, exceeding the specified expansion value ； 7) Flare corrosion, flaking, with the flare exposure less than 2-3 mm.
(1) Presence of bulges, cracks, or network-like cracks; (2) Severe corrosion; (3) Bending degree greater than 1.5–2 times the outer diameter of the furnace tube; (4) Outer diameter greater than 4–5% of the original outer diameter.
Answer: 1) There are bulges, cracks, or network-like cracks； 2) The bending degree between two adjacent supports of the horizontally placed furnace tube is greater than 2 times the outer diameter of the furnace tube ； 3) The furnace tube is due to severe corrosion, wall cracking, and a wall thickness below the calculated allowable value ； 4) The outer diameter is 4-5% larger than the original outer diameter ； 5) Corrosion and detachment of the flared portion, with the exposed part of the flare being less than 2-3 millimeters ； 6) The flare is expanded repeatedly during use, exceeding the specified expansion value.
Thickening of wall thickness, burn-through, thickening
(1) There are bulges, cracks, or network-like cracks. (2) Severe corrosion. (3) The degree of bending is more than 1.5 times the outer diameter of the furnace tube. (4) The outer diameter is more than 4.5% larger than the original outer diameter.
1) Presence of bulges, cracks, or network-like cracks; (2) Severe corrosion; (3) Bending degree greater than 1.5–2 times the outer diameter of the furnace tube; (4) Outer diameter larger than 4–5% of the original outer diameter; (6) Excessive expansion due to repeated expansion operations during use, exceeding the specified limits, etc.
No time limits are specified for the decommissioning, scrapping, or cancellation of pressure pipelines. Article 103: The entity using the pipeline shall, either before its use or within 30 days after its use, go to the local quality and technical supervision department to complete the registration for the use of the pipeline in accordance with the requirements of the \"Rules for the Registration Management of Pressure Pipelines\".
Severe thinning of the furnace tubes, burn-through of the furnace tubes, reached the end of its service life
(1) There are bulges, cracks, or network-like cracks. (2) Severe corrosion. (3) The curvature is 1.5–2 times greater than the outer diameter of the furnace tube. (4) The outer diameter is 4-5% larger than the original outer diameter. (6) During use, the flaring is performed repeatedly multiple times, exceeding the specified value. (7) Flare corrosion and detachment.