LIQUID FEED PUMP AND LIQUID CHROMATOGRAPH

摘要

[Problem] To prevent corrosion and etching of wall surfaces of a pump head and to prevent deterioration in the sealing performance of a plunger seal. [Solution] A recess (8d) into which a projection (10a) of a plunger seal (10) is to be fitted is provided in a part in which a plunger (3) is inserted toward a pump chamber (8a) of a pump head (8). By fitting the projection (10a) into the recess (8d) and pressing the plunger seal (10) toward the side of the pump chamber (8a) with a backup ring (11), the outer peripheral surface of the projection (10a) is brought into tight contact with the inner peripheral surface of the recess (8d), and the surface of a flange (10b) on the side of the projection (10a) is brought into tight contact with the peripheral edge surface of the recess (8d) of the pump head (8), and thus, the plunger seal (10) seals the pump chamber (8a). The inner peripheral surface of the recess (8d) of the pump head (8) and the peripheral edge surface of the recess (8d) are covered with an acid-resistant material film (14).