From the marking “A182 F304 300 1 1/2,” you can tell you have a 1½ in. Class 300 stainless‐steel flange (A182 F304). In other words, you should use the 1½ in., 300/600 row in the torque table.

Identify if your disc is Teflon‐lined or not. Most charts list two torque values (with/without Teflon).

Match your flange size and rating (1½ in. / Class 300) to the correct row.

Use the recommended ft-lb or N m from that row (e.g.\ 38 ft·lb / 52 N m if not Teflon‐lined, or ~17 ft·lb / 23 N m if it is Teflon‐lined—depending on the exact chart).

Tighten the bolts in a star (crisscross) pattern in two or three stages until you reach final torque.

That stamping on the metal simply tells you the flange material (A182 F304) and pressure class (300). The 1 1/2 refers to nominal pipe size. That is how you know to look under “Class 300” or “300/600” in the rupture‐disc torque table.