【Q&A Question 306】November 20, 2017
Thread Content
【Q&A Question 306】November 20, 2017: What are the common reasons why gaskets fail to provide a proper seal? Answer: The common reasons why gaskets fail to provide a proper seal are: (1) The material or shape of the gasket was chosen improperly, and it is not suitable for the operating conditions ； ⑵Insufficient, uneven gasket compression or missing installation ； ⑶Repetitive heat and cold cycles, large fluctuations in fluid temperature and pressure, or vibrations ； ⑷Under temperature and pressure conditions, the bolts elongate and loosen due to gasket creep. (Unless otherwise specified, all questions and answers are based on hydrogenation units.) ) For management purposes, if you need to view content from a few days ago, please go through the summary post below. 2017 Q&A Summary Thread (updates have begun) http://bbs.hcbbs.com/thread-1657793-1-1.html 2017 Daily Question Summary Thread (updates have begun) 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 (Source: Haichuan Chemical Industry Forum)
Incorrect selection of material or model, improper choice of size and width, uneven pressure, excessive pressure, or insufficient pressure, etc
1. Improper selection of the material or type of gasket, which is not suitable for the operating conditions. 2. Incorrect selection of the gasket’s thickness and width. 3. The gasket is not compressed sufficiently, or the compression is excessive or uneven; it may also be installed incorrectly. 4. Large fluctuations in fluid temperature and pressure, as well as vibrations, due to thermal cycling of the pipes. 5. Creep of the gasket or elongation and loosening of the bolts under certain temperature and pressure conditions. 6. Damage to the flange surface caused by pitting or deformation. 7. Insufficient smoothness of the flange surface, or inadequate cleaning of the flange surface when removing the old gasket.
1. The sealing surface is damaged. 2. Using gaskets of an unsuitable pressure rating. 3. The tightening force of the flange bolts is insufficient. 4. Overpressure. 5. Reuse of gaskets.
Damage to the sealing surface, misalignment of the gasket, mismatched gaskets
1. Improper selection of the material or type of gasket, which is not suitable for the operating conditions. 2. Incorrect selection of the gasket’s thickness and width. 3. The gasket is not compressed sufficiently, or the compression is excessive or uneven; it may also be installed incorrectly. 4. Large fluctuations in fluid temperature and pressure, as well as vibrations, due to thermal cycling of the pipes. 5. Creep of the gasket or elongation and loosening of the bolts under certain temperature and pressure conditions. 6. Damage to the flange surface caused by pitting or deformation. 7. Insufficient smoothness of the flange surface, or inadequate cleaning of the flange surface when removing the old gasket.
1. Improper selection of the material or type of gasket, which is not suitable for the operating conditions. 2. Incorrect selection of the gasket’s thickness and width. 3. The gasket is not compressed sufficiently, or the compression is excessive or uneven; it may also be installed incorrectly. 4. Large fluctuations in fluid temperature and pressure, as well as vibrations, due to thermal cycling of the pipes. 5. Creep of the gasket or elongation and loosening of the bolts under certain temperature and pressure conditions. 6. Damage to the flange surface caused by pitting or deformation. 7. Insufficient smoothness of the flange surface, or inadequate cleaning of the flange surface when removing the old gasket.
1. Improper selection of the material or type of gasket, which is not suitable for the operating conditions. 2. Incorrect selection of the gasket’s thickness and width. 3. The gasket is not compressed sufficiently, or the compression is excessive or uneven; it may also be installed incorrectly. 4. Large fluctuations in fluid temperature and pressure, as well as vibrations, due to thermal cycling of the pipes. 5. Creep of the gasket or elongation and loosening of the bolts under certain temperature and pressure conditions. 6. Damage to the flange surface caused by pitting or deformation. 7. Insufficient smoothness of the flange surface, or inadequate cleaning of the flange surface when removing the old gasket.
1. Improper selection of the material or type of gasket, which is not suitable for the operating conditions. 2. Incorrect choice of the gasket’s thickness and width. 3. The gasket is not compressed sufficiently, or is compressed too much, unevenly, or in an incorrect position. 4. Fluctuations in fluid temperature and pressure due to thermal cycling, as well as vibrations. 5. Creep of the gasket or elongation and loosening of the bolts under certain temperature and pressure conditions. 6. Damage to the flange surface caused by pitting or deformation. 7. Insufficient smoothness of the flange surface, or inadequate cleaning of the flange surface when removing the old gasket
Problems with the gasket quality, defects in the flange, improper installation
1. Improper selection of the material or type of gasket, which is not suitable for the operating conditions. 2. Incorrect selection of the thickness and width of the gasket. 3. The gasket is not compressed sufficiently, or is compressed too much or unevenly, or is installed incorrectly. 4. Large fluctuations in fluid temperature and pressure, as well as vibrations, due to thermal cycling of the pipes. 5. Creep of the gasket or elongation and loosening of the bolts under certain temperature and pressure conditions. 6. Damage to the flange surface caused by pitting or deformation. 7. Insufficient smoothness of the flange surface, or poor cleaning of the flange surface when removing the old gasket