Basic - (example: Hydraulic engineering) searches for the entered expression in an exact match with the entry - i.e. in the order in which the words follow each other.
Logical OR - (example: butterfly valve OR lattice disc) pages containing one, the other, or both of the entered keywords will be included in the results.
Logical AND - (example: ASME AND internal pressure) only pages containing both required words will appear in the results.
Logical NOT - (example: spherical NOT ASME) pages containing the name "spherical" but not containing the word "ASME" will be displayed in the results.
Category 1 Flange: An integral flange or an optional flange calculated as an integral flange.
Category 2 Flange: A loose type flange with a hub where credit is taken for the strengthening effect of the hub.
Category 3 Flange: A loose type flange with a hub where no credit is taken for the strengthening effect of the hub, a loose type flange without a hub, or an optionaltype flange calculated as a loose type without a hub. Substitute $B$ for $B_1$ in the applicable equation for this category of flange.