You question is too short to give a good answer. What do you mean with Cl 600#? With respect to what standard? Are you talking about flanges? And what material spec? Grade B itself doesnt tell much.
Still not sure what you mean. You have to be more specific.
600# is a pound class rating used for ASME flanges, referring to a pressure rating. Grade B is a material grade, reffering to material properties within the API 5L specification.
Well, while we're at it we might as well read a B16.5 from the 1990's or newer - not some vendor's catalog since we don't want to spend the money on the actual standard - and discover the utter lack of # in terms of ratings. There ain't no such thing as a 600$ flange unless it was bought 30 years ago... But Class 600, yep, we got those.
api 5l grade b is the material as previously said, it's carbon steel.
600# refers to the flange class, look for a copy of B16.5. The class sets the maximum pressure that flange can withstand for a given material of construction and temperature.
Ehsan, you're not getting any answers because your question is not clear.
API 5L Grade B refers to Grade B material per API 5L "Specification for Line Pipe". As its title suggests, API 5L applies to Line Pipe, but it has nothing to do with insulation. It also does not include pressure ratings.
Class 600# isn't stated very well. Currently, it's correct (and sufficient) to call this Class 600. To add the "pound symbol" (#) is unnecessary because these are now called pressure classes, which are dimensionless, and so any reference to "pounds", "psi", "#", and so on is incorrect. But the pressure class alone (such as Class 600) isn't sufficient because it needs some reference to a standard that defines what it means. That could be ASME B16.5 "Pipe Flanges and Flanged Fittings". Or it could be something else. Without additional information, we're just guessing.
In any case, it sounds like you have a partial specification for some sort of steel pressure-containing "something" for which you have a material designation and pressure class. But that has nothing to do with insulation. If you're dealing with an insulating jacket that goes around this pressure-containing "something", then you haven't given us anything relevant to that. So we cannot answer your question beyond what was already given.
Your initial question was, "what is different between class 600# and grade b? and can we have material whith grad b and class 600#?" The answer is that one is a pressure class and the other is a material grade. They're two different things.
Also API 5L gr B is a material specification for pipe. Flanges are not made from this material. The flange material would be made from another specification, e.g A105.
Class 600 is dimension specification for flanges. All class 600 flanges have the same dimensions. But the pressure rating depends on the material and temperature.
