Pressure guaranteeing device for double-end-face mechanical seal isolation cavity of self-priming pump

The invention relates to the technical field of self-priming pumps, in particular to a pressure guaranteeing device for a double-end-face mechanical seal isolation cavity of a self-priming pump, which comprises a mechanical seal shell fixed on the lower end face of the double-end-face mechanical seal isolation cavity and located above an impeller and on the periphery of a pump shaft, a mechanical seal lower cover is arranged at the lower end of the mechanical seal shell, and the mechanical seal lower cover is in clearance fit with the pump shaft. A back blade is arranged on a rear cover plate of the impeller and is in clearance fit with the mechanical seal lower cover; an oil storage tank is arranged on the outer side of the self-priming pump shell and higher than the double-end-face mechanical seal isolation cavity. The oil storage tank communicates with the double-end-face mechanical seal isolation cavity through an oil conveying pipe. A gas-liquid isolation settling box communicated with the self-priming p