Class 125 Pressure/Temp Ratings 1

[TangoCleveland]

I'm working on a 1950's vintage piping system. We have a welded slipon flange, 48" pipe OD, 2.75" thick. In this part of the system, class 125 flanges are common. Where can I find pressure-temperature ratings for class 125 steel flanges? ASME B16.1 covers cast iron flanges in class 125, ASME B16.47 covers large flanges in steel, but not class 125. Can anyone provide pedigree information for class 125 steel flanges in 48" diameter?

Thanks in advance.

Larry

 

[JStephen]

AWWA C207 shows Class D flange in 48" as 1.875" thick, and with a 150 PSI rating (at ambient temperature, potable water service). If that helps any.

API-650 includes the 2.75" thick 48" flange in its nozzle tables, but I don't see any pressure rating given.

 

[TangoCleveland]

My old Taylor Forge catalog says the Class 125 flange is dimensionally equivalent to the AWWA C207 Class E. AWWA is fine for ambient temperature. This flange is on a 300°F compressor discharge line.

Larry

 

[ApC2Kp]

To MechSlipStick,
The AWWA C207 Class E flanges are rated 275 psig for water service. The similar ASME B16.47 CL150 flange at 2.56 inch thickness has a rating 285 psi at 100 deg F, and de-rated to 230 psi at 300 deg F. (Table 2). These are also the same ratings as for B16.5 CL150 steel flanges (size to 24).
I think it would be conservative to rate the AWWA C207 Class E flange with 2.75 inch thickness to be at least the equal to B16.47 CL150 flange with 2.56 inch thickness for 300 deg F. service.

 

[unclesyd]

Check this website out.

http://www.texasflange.com/Dimensioncutsheet.htm

 

[JStephen]

My flange table showed the Class E to be heavier than 2.75", I believe- will have to recheck.

 

[TangoCleveland]

Thanks, ApC2Kp. Another small catch is that B16.47 has two "Series" of Class 150 Flanges. Series A is the "normal" flange, and Series B is called a "compact" flange. The two series have different bolt circles, so they aren't interchangeable. However, the overall dimensions of the Series B flange are very close to the Class 125 dimensions, except for bolt circle. Since the area on which the system pressure is acting is the same for both flanges, I will recommend that we use B16.47 Class 150 Series B pressure temperature ratings for our steel Class 125 flanges.

Larry