Abstract: The present invention is a one-way fluid valve which consists of a shuttle chamber (29) with its two ends connected with the two fluid openings (22,22'), a shell (2) incorporating a by-pass (20) which is connected with the two ends of the shuttle chamber, a plunger (1) inserted in the shuttle chamber, and two throttling control elements (3,3') placed at the two ends of shuttle chamber used for controlling the stroke of the plunger. This kind of shuttle valve may be installed in a single pipe-line, the fluid may flow through it in forward and backward directions. It has the function of regulating the flow-rate of fluid forward and backward, hence is able to handle unequal flow-rates forward and backward. It can also function as one-way non-return valve, two-way alternating non-return valve and can be totally shut and fully opened.