What is the proper definition of ANSI Class? 2

[bao2ye]

I think it is a designated reference class number. But which standard gives a clear definition of ANSI Class................?

Thanks in advance.

 

[arash807]

Different pressure and temperature rating are defined in ASME B16.34 table2.

 

[hsbcn]

You'll find that pressure classes 150#, 300#, 600#, 900# and 1500# are the most common for flanged valves, and 800#, 1500# and 2500# for SW and NPT valves.

My focus is on valve stockists in the us and us who supply duplex and super duplex valves, and inconel and hastelloy valves, plus titanium, alloy 20 and 904L valves.

 

[bcd]

ANSI is the American National Standards Institute. It is the highest level a standard can attain in the USA. Years ago, ANSI delegated management of pressure standards, includes those for valves, flanges, pipelines, to ASME. So the propoer termonology is actually ASME Class.... However, ANSI was mentioned for so long that it is still mentioned today by habit.

API valve standards define the Class very well:

Class - an alphanumeric designation that is used for reference purposes relating to valve pressure/temperature capability, taking into account valve material mechanical properties and valve dimensional characteristics. It comprises the letters "Class", followed by a dimensionless whole number (i.e. 150, 300, 600, etc.). The number following the letters Class do not represent a measurable value and are not used for calculation purposes except where speficied in the applicable design standard. The allowable pressure for a valve having a Class number depends upon the valve material and its operating temperature, and is found in the ASME B16.34 tables for pressure/temperature ratings. Use of Class ratings is applicable to valves using NPS size designations.

 

[bao2ye]

I agree with BCD's comments. Thanks for you guys help.

 

[hsbcn]

thanks, bcd, for the input!

My focus is on valve stockists in the us and uk who supply duplex and super duplex valves, and inconel and hastelloy valves, plus titanium, alloy 20 and 904L valves.