NOTE: Pressure-temperature ratings in the following charts are reported from ASME B16.11 - 1966 and are for historical reference only. As per latest revision of ASME B16.11, pipe fittings are rated based on the schedule number (wall thickness) of appropriate size seamless pipe of equivalent material. Following is the correlation between fitting's class and schedule number of the pipe for calculation of pressure rating:

Class of Fitting	Type of Fitting	Pipe used for Rating Basis
		Schedule No.	Wall Designation
2000	Threaded	80	XS
3000	Threaded	160	---
6000	Threaded	---	XXS
3000	Socket Weld	80	XS
6000	Socket Weld	160	---
9000	Socket Weld	---	XXS

• A105 (Carbon Steel)	• F304 (18-8)
• F5 (5 Cr)	• F304L (18-8 LC)
• F9 (9 Cr)	• F316 (18-8 Mo)
• F11 (1-1/4 Cr)	• F316L (18-8 Mo-LC)
• F22 (2-1/4 Cr)	• F321 (18-8 Ti)
	• F347 (18-8 Cb)