Valve device

A valve device comprising:

• an outer valve casing externally fitted to an existing fluid pipe;
• an inner valve casing housed in the outer valve casing and having a valve body capable of shutting off or switching a flow path of a fluid flowing in the existing fluid pipe;
• and
• an inner packing arranged to seal a gap between the outer valve casing and the inner valve casing,
• wherein
• the inner packing includes an annular portion mounted along a periphery of an upper side surface of the inner valve casing and a plurality of U-shaped portions extending downward from the annular portion and to be mounted over an entire length from a side surface to a bottom surface of the inner valve casing, and each U-shaped portion contacts the side surface and the bottom surface of the inner valve casing,
• an enclosed space sandwiched between an inner surface of the outer valve casing and an outer surface of the inner valve casing is formed between the U-shaped portions that are adjacent to each other, and
• the inner packing is provided with a connecting portion for connecting the plurality of U-shaped portions to one another
• wherein the enclosed space extends vertically at a plurality of positions on the side surface of the inner valve casing so as to communicate with one another on the bottom surface side of the inner valve casing.