Regarding the issue of US standard pressures, the difference between CL and LB
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This post was last edited by kshzq on 2011-6-30 09:54. Many people think that these two terms convey the same meaning – both CL300 and 300LB indicate 300 pounds. However, I’ve also heard that there is a difference between these two units; 300LB simply means 300 pounds, and it isn’t affected by factors such as temperature, remaining constant at 300 pounds at all times. On the other hand, although CL300 also represents 300 pounds, its actual operating pressure changes if the temperature changes. I don’t know if everyone can understand it when I put it this way, and I also don’t know if this expression is correct; please provide a proper explanation.
This post was last edited by zero229 on 2011-6-30 10:04. The difference between them is the same as that between PN2.0 and 2.0Mpa. In our terms, one is the nominal pressure and the other is the actual pressure. I’m not sure if you can understand it this way.
Agree with what was said above; 300LB means 300 pounds, which is essentially equivalent to CL300
Learning*learning*: I used to think they were the same thing, like a theoretical value and an actual value.
Why do I think one is the flange pressure rating and the other is the valve pressure rating?
You are right; one is the pressure rating of the flange, and the other is the pressure rating of the pipe. But I’m also puzzled as to why two different methods are used
A little more brightness and a little less darkness – and the whole world becomes more beautiful
For example: CL300 = CLASS 300; CL is just an abbreviation for CLASS. LB = CLASS 300LB – in everyday language it is referred to as 300 pounds, and it is commonly written as 300LB or 300#, or CLASS 300LB. On official drawings, CLASS 300LB or CLASS 300# will be indicated. I’m not sure if this explanation is clear enough
It’s up to the design institute or individual*; there’s no such rule.
There’s no difference; one is a unit and the other is a level – they refer to two different parameters, but they convey the same meaning