Self-priming chemical pump

A self-priming chemical pump comprising:

• a pump portion including at least an impeller and a shaft supporting said impeller;
• a self-priming mechanism portion including a self-priming chamber which is provided in the discharge side of a vortex chamber of said impeller so as to communicate with a discharge opening, and a suction chamber which is provided in the suction side of said vortex chamber of said impeller so as to communicate with a suction opening;
• a seal wall which is provided in the vicinity of the discharge side of said vortex chamber to form a slight gap along the outer circumference of said impeller;
• and
• a circulation hole which is provided in said self-priming chamber so as to be located inside the outer circumference of said impeller,
• wherein said suction chamber comprises an L-shaped suction passage for making said suction opening communicate with the suction side of said vortex chamber, and a self-priming liquid remaining portion having pores communicating with said suction passage;
• and wherein said self-priming chemical pump further comprises a siphon-cut shortest passage which is provided in said suction passage, and the volume of said self-priming chamber is substantially equal to the volume of said suction chamber.