| 摘要 |
PROBLEM TO BE SOLVED: To achieve the common use of piping of two systems with a simple structure and to prevent the exertion of an adverse influence of backflow, etc., on a mating side even if pumps operate independently from each other. SOLUTION: When the pump 302 disposed at the piping of the first system operates, the force to suck a processing liquid 204 out of a piping port 312 on the lower side of a check valve 306 is exerted thereon. At this time, a valve element 322 closes an aperture 312A on the lower side by its own weight and therefore the backflow is prevented. When, on the other hand, the pump 212 disposed at the piping of the second system operates, the processing liquid 204 eventually flows vigorously into the check valve 306 from the piping port 312 on the lower side. The valve element 322 is moved like imaginary lines of Figure 4 by this vigor and the aperture 312A is opened, by which the processing liquid 204 is smoothly passed through the check valve 306 into a cooler 208. |
