What is "blind flange"

Flange \Flange\ (fl[a^]nj), n. [Prov. E. flange to project, flanch a projection. See Flanch, Flank.]

1. An external or internal rib, or rim, for strength, as the flange of an iron beam; or for a guide, as the flange of a car wheel (see Car wheel.); or for attachment to another object, as the flange on the end of a pipe, steam cylinder, etc.
   --Knight.

2. A plate or ring to form a rim at the end of a pipe when fastened to the pipe.

   Blind flange, a plate for covering or closing the end of a pipe.

   Flange joint, a joint, as that of pipes, where the connecting pieces have flanges by which the parts are bolted together.
   --Knight.

   Flange rail, a rail with a flange on one side, to keep wheels, etc. from running off.

   Flange turning, the process of forming a flange on a wrought iron plate by bending and hammering it when hot.