Questions regarding ordering requirements for low-temperature stud nuts and the selection of high-hazard flange gaskets
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The medium is highly hazardous; the design temperature is -60°C. The studs of the pipe end flange are made of 35CrMoA, while the nuts are made of 30CrMoA. The supply conditions I specify are: conducting an impact test at -60°C, with an impact energy of ≥41 J； Chemical composition (melting analysis): P≤0.02%, S≤0.01% (according to 150.2-7.1.4). However, 150.2-7.1.4 applies only to studs; are additional technical requirements needed for nuts? I checked 20592 and found only the following requirement, which applies to 35CrMo material (without distinguishing between studs and nuts). For highly hazardous media, regulatory requirements specify the use of WN flanges, high-strength studs, and metal wound gaskets with reinforcing rings. What exactly does \"reinforcing ring\" mean? The customer for this equipment requires a TG-sealed surface, so only Type A wound gaskets can be used. Type A wound gaskets do not have inner or outer rings; do they come with a reinforcement ring? Can toothed gaskets be used for gaskets of extremely highly hazardous and highly permeable moderately hazardous media? Do we really have to choose gasketing according to the capacity specifications?
That’s a good question; let someone who understands it answer it
1. The nut is also subjected to -60-degree impact testing. 2. The tenon and mortise surface gasket can be without a ring. 3. Toothed pads can be used
1. Studs and nuts can withstand impacts at -70 degrees; per the standards, it’s also acceptable to use them at -60 degrees. 2. The tenon and mortise surface gasket can be without a ring. 3. Toothed pads can be used
Without a reinforcement ring, it’s likely the inspectors from the special inspection agency won’t overlook it. I remember that the old \"Rong Regulations\" specified the use of internal reinforcement rings, but we used external reinforcement rings, and the special inspection agency refused to conduct inspections on us.
What does the reinforcement ring mentioned in the tolerance specifications refer to?
What does the reinforcement ring mentioned in the tolerance specifications refer to? -Should 70 Impact be made more secure?
Does the reinforcement ring mentioned in the tolerance specifications refer to the inner and outer rings of the gasket?
Yes, it refers to the inner ring or outer ring of the gasket
Types D, C, and B of gasketing all come with reinforcing rings. The standard value is usually -70 degrees; generally, tests are conducted at temperatures that are not lower than the design temperature. It’s also fine to use 60 degrees in your case.