A peripheral sealing assembly for connection with a buoyant panel unit usable in a liquid storage tank includes a fixing frame, an enclosure, and a buffer pipes. The fixing frame connects the buoyant panel unit. The enclosure is fixed to the fixing frame to sealingly contact an inner surrounding wall of the liquid storage tank. The enclosure defines a looped receiving space between the inner surrounding wall and the buoyant panel unit. The buffer pipes are inserted into the looped receiving space. Each buffer pipe is hollow, extends along the looped receiving space and has a lengthwise outer peripheral surface fixed to the lengthwise outer peripheral surfaces of two adjacent other buffer pipes.