PURPOSE: A backward flowing prevention spuit is provided to improve the reliability of a product by preventing solution to be backed up to a compression part. CONSTITUTION: A top adhering part(103) is projected to a curve shape according to a columnar direction. The top adhering part is projected in the fixed location of the bore upper part of an inlet tube. A bottom adhering part(104) is projected according to the columnar direction toward caliber center. The bottom adhering part is projected to the curve shape. A close adhesion member(105) is inserted between the top adhering part and the bottom adhering part. The close adhesion member comprises a plurality of distribution grooves in a diameter surface.
