These fittings shall be designated as pressure class 1000, 3000 and 6000 fittings for threading and pressure Class 3000 & Class 6000 for socket-weld. This designation identifies the fittings with their ratings as shown as follows, Table 1.
BM - MS Forged Pipe Fittings
Table 1 : Correlation of Fittings Class With Schedule Number of Wall Designation of Pipe for Calculation of Ratings
Designation of Fittings
Pipe Used for Rating Basic
1000 Lbs. Threaded 40 3000 Lbs. Threaded 40 & 80 6000 Lbs. Threaded 160 3000 Lbs. Socket-Weld 80 3000 Lbs. Socket-Weld 80 3000 Lbs. Socket-Weld
This table is not intended to restrict the use of pipe of thinner or thicker wall with fittings. Pipe actually used may be thinner or thicker in
nominal wall than that shown in Table 1. When thinner is used its strength may govern the rating. When thicker pipe is used (e.g., for
mechanical strength) the strength of the fitting governs the rating.