Welding flange is a flange type that flange welded on pipe to joint two pipes, welding flanges type for slip on flange, weld neck flange, plate flange, blind flange, socket weld flange and lap joint flange, but threaded flange (screwed flange), part of lapped flange (loose flange) and backing rings are not welding on pipes, they are use thread to thread pipes for connection.
