PURPOSE: To freely and most properly set the dimension of an outer passage and prevent abrasion and clog by providing a passage communicating the intake valve side of a cylinder with the discharge passage side in the outside of the cylinder, and disposing a discharge valve on this outside passage.

CONSTITUTION: A coating material which is a force-fed fluid, for example, is sucked into an intake valve chamber A in the lower part of a cylinder 3 by the lifting of a rod 1. The coating material is run into the outer valve 20 side by the lowering of the rod 1, and introduced into a discharge valve chamber B by pushing up a ball 25. The coating material is further passed through the cylinder 3 and discharged from a discharge port 10 by the re-lifting of the rod 1 in the state where the counter flow is prevented by the ball 25. Thus, the coating material can be regularly discharged by the lifting and lowering of the ball 25. By providing such an outer passage having the ball 25 independently from the cylinder 3, the outer passage is set to the optimum dimension according to the flow rate and pressure of the coating material, so that abrasion and clog can be prevented.