ANSI Classes & Differential pressure 1

[bourne03]

hi,

i noticed that each valve is manufactured accordingly to
ANSI class which i suppose it is something to do with the
pressure rating.
ex : 2" ball valve ANSI class 600
can anyone help me by telling me what does ANSI classes
refers to and how does these classes being rated and is
there any website where i can get more details ?

secondly, is there a formula to calculate differential
pressure of a system ? take a 2" ball valve for instant.
does it relate to Cv of a valve ?

hoping to know

bourne

 

[owlscreech]

See Thread 408-21855 for discussion of Class. Allowable pressures are directly related to the class number, e.g., a Class 600 valve can operate at twice the pressure as a Class 300 for a given temperature/material. However, this relationship does not apply to Class 150. See ASME B16.34 Annex F for specifics.

Cv is related to the type of valve, the manufacturer's particular design (which establishes the flow geometry), and size. If you need to size a valve, use the manufacturers Cv tables.

 

[TD2K]

I'd suggest you take a look at ANSI B16.5. There should be a copy around your workplace. Most pressure valve catalogs will also have excepts from it for the pressure/temperature tables but they won't have the entire text for you to read.

 

[bourne03]

to owlscreech and TD2K,

thanks for your precious information.

best regards,

bourne