An apparatus for allowing the repetitive oscillation of pressure in a container or vessel having a finite volume. The apparatus comprises a valve having first opening, a valve enclosure having a second opening, and a first tension device. In some embodiments the apparatus can have a chamber capable of oscillating in volume. The oscillation of the chamber volume causes a decrease in the pressure of the container. As the pressure of the space or container decreases, two openings of the apparatus become more proximate. Eventually the openings partially overlap, allowing a gas, or fluid, to enter the container, increasing pressure of the space or container. As a result of the pressure increase, the first opening and second opening become less proximate by a force of the first tension device. The apparatus can allow the container to approach substantially perfect vacuum and rise toward atmospheric pressure.