Piping classes

[Melimelo]

Hello everybody!
Can anyone tell me why the primary rating are:
150#
300#
400#
600#
900#
1500#
2500#?
Why there is not 200# or 1000# or any other number...?
How did we get these numbers?
I'm sure there is an explanation like for the ND of pipes (coming from Renard series).
Thanks a lot!
Méli )

 

[JLSeagull]

Obtain a current copy of ASME B16.5. This will provide much of the historical background as well as the actual pressure and temperature tables for each of the many materials. This is an essential standard.

 

[pennpiper]

Read this article:

http://www.pipingdesigners.com/Training - section 1d.htm

 

[JLSeagull]

Obtain a copy of ASME B16.34 for valves if you cannot obtain ASME B16.5 for flanges. Begin now to eliminate the term pound (#) that we previously discussed. Using # is just wrong. ;-) Instead use Class 150, Class 300, Class 400, Class 600, Class 900, Class 1500, Class 2500, Class 4500 etc.

 

[Melimelo]

Hello guys!
Just to say I have found other information on another forum:
Just go to "Piping and fluid mechanical forum" and tape: "Piping classes origin", you will find an interesting discussion...
See you!
Méli )

 

[dcasto]

you can make any class you want. I have a lot of plants with 6" and 8" lines going to vessels with 100 or 100 psi MAWP. I'm not going to use sch80 pipe that costs 1.5 times as much as sch 40, so I limit them to a 1100 psi mawp.

why spend the extra money installing pipe that can never be utilized fully. Same is true especially with 304SS, no need in sch40 when sch10 will work.