Technical discussion posts on gasket design, selection, installation, failure analysis, etc
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This post was last edited by Sammy_Wang on 2015-12-17 08:19. Gasketing is widely used in machinery, equipment, pipelines, and high/low pressure vessels as materials that provide sealing functionality. Its sealing performance is highly dependent on the initial design, selection, and installation of the gasket. I posted this with no other intention than for technical exchange, to help us all improve. We welcome Sea Friends to ask questions and engage in discussions regarding seal gaskets.
I think that with a pressure of 150 LB, there is no difference in the use of C-type gaskets and D-type gaskets, right?
I’m sorry for taking so long to respond – the issue you mentioned likely refers to gasketing. When ordering under a pressure of 150 lb, either type C or type D can be chosen. However, the selection of gaskets should take into account various factors such as the properties of the medium, temperature, pressure, and operating conditions. In the case of corrosive media, it is recommended to use gaskets with a metal inner ring, as this can provide significant protection for the sealing surface. For large-sized metal wrapping bands, it is also recommended to have metal inner and outer rings (depending on the flange type) to improve their rigidity. For reference only!
Hello, I have a question regarding the material selection for gaskets and would like to ask for advice. I have a kneader here; the pH of the medium is 3–4, and the ambient temperature is 300. What material should be used for the static seals at the two cut ends?
The selection of this gasket depends primarily on the temperature of the medium. Please provide the name of the medium, the pressure, and whether it is a new design. If it is a replacement part, please specify the type of sealing required.
The main component of the medium is maleic acid, at normal pressure. It’s mainly the high temperature. Rectangular shape: 1100*800. Now that we use PTFE gaskets, their lifespan is barely less than 1 year. Since disassembly is very inconvenient, I want to choose a material with a longer lifespan.
With a medium of maleic acid and a temperature of 300 degrees, the current selection of gaskets is based on no rationale at all. HG20606 specifies that pure PTFE can operate at temperatures ranging from -50 degrees to +100 degrees Celsius, while filled or modified PTFE can handle temperatures from -200 degrees to +200 degrees Celsius. These values refer to non-continuous operation conditions; in practice, neither pure PTFE nor filled or modified PTFE can meet the requirements of your application. Personal suggestion: 1. Use flexible graphite gasket sheets with a 316L lining on the sprint board; this will greatly improve the situation. 2. If the equipment is to operate for extended periods of time, I personally recommend using high-temperature mica or high-temperature thermoculite gaskets (thermiculite 815). I hope this is useful; thank you.
Thank you for the help. I’ll give Heat Resistant Glue 815 a try
From what you say, have you been in contact with 815 before?
I’ve never used it. Someone recommended it to me when I was at a coking plant; at that time I thought it was too expensive and not useful.