Blind plate, also known as Flange cover or Blind flange, is a type of flange without a hole, used to seal pipe openings. It serves the same function as a cap or pipe plug, but the blind plate sealing is a removable device, whereas the cap sealing is not intended for future openings. The sealing surface comes in various forms, such as flat, convex, concave-convex, tenon-mortise, and annular joint surfaces. Materials include carbon steel, stainless steel, alloy steel, copper, aluminum, PVC, and PPR.