Extinguishing agent storage tank of heptafluoropropane gas extinguishing system

The utility model relates to a gas extinguisher, and particularly relates to an extinguishing agent storage tank of a heptafluoropropane gas extinguishing system. Multiple heptafluoropropane gas extinguishing systems have the problems of bad sealing of the extinguishing agent storage tank and frequent leakage of an extinguishing agent in the prior art, and the usage property and service life of equipment are seriously influenced. The extinguishing agent storage tank comprises a container valve, a pilot valve, a safety helmet, a pressure gage and a siphon pipe, wherein the container valve is in a horizontal pressure difference type dual-sealing structure; a piston inside the container valve is provided with a radial sealing ring and an axial sealing ring; the container valve is provided with the detachable pilot valve; the outlet of the container valve is provided with the safety helmet; the container valve is provided with the pressure gage, and the pressure gage is connected with a pressure gage switch; the container valve is provided with a safety pressure relief device; and the siphon pipe is arranged at the bottom of the container valve, and a pressure relief groove is arranged at the top of the siphon pipe. The sealing device disclosed by the utility model has the advantages of novel structure, stability in property and safety in use.