Can pressure pipes made of Q345B replace those made of Q345C?
Thread Content
A pressure-bearing pipe section was designed to use the Q345C material specified in GB/T 8163-2008; however, the material that arrived actually was Q345B. Can B be used as a substitute for C? At present, here are the differences between the two: Q345B: elongation after fracture is 20%, and the impact test temperature is +20 degrees Celsius ； Q345C: Elongation after fracture is 21%, and the impact test temperature is 0 degrees Celsius.
This represents replacing a lower level with a higher one; it depends on the actual design requirements, and the designer can approve it if those requirements are met.
What data do you need to confirm?
This is the basic skill of a designer; it’s a long story to explain – things like design temperature, pressure, and the operating conditions.
In other words, when choosing Q345C, use this approach to consider whether Q345B will work as well. If there are no problems, it indicates that the materials chosen for the design are of a higher quality than necessary.
Oh, I don’t understand; I’m not a designer. If you see people using sitting toilets, then you naturally won’t want a squat toilet. :Lol: The operating temperature is the ambient temperature, usually not lower than +4 degrees ； The test pressure is 7625 psig.
A temperature of not lower than 0 degrees will suffice.
It doesn’t matter if you don’t have the basic skills; your boss will hold you accountable. I’m not going to be that jerk. ;P
What is the purpose of performing this impact work, after all? It should be no lower than 0 degrees; does that mean Q345A can be used in all cases?
Low-temperature impact depends on the operating temperature; if that temperature is met and the impact energy meets the requirements, it indicates that the material has good toughness at that temperature and is less prone to brittle fracture.
Oh, then it seems to not meet the requirements; Q345B requires +20 degrees, which is almost like being at the equator.