BUFFER GATE, PUMP INTRODUCTION METHOD, AND PUMP LIFTING METHOD

The present invention relates to a buffer gate for use in isolating inside and outside of a pump column when a submersible pump for pressurizing liquefied gas, such as liquid hydrogen, is carried into the pump column and when the submersible pump is pulled up from the pump column. The buffer gate (1) is configured to isolate the inside and the outside of the pump column (3) in which the submersible pump (2) is disposed, the submersible pump (2) being for delivering the liquefied gas. The buffer gate (1) includes a buffer box (14) having a buffer chamber (12) therein, a first partition wall (16) configured to close an upper opening of the buffer box (14), a second partition wall (17) configured to close an upper opening of the pump column (3), and a purge-gas inlet port (20) communicating with the buffer chamber (12). The buffer box (14) is fixed to an upper end of the pump column (3).