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.

A double port regulator assembly includes a first fluid port and a second fluid port. A fixed valve seat assembly is disposed proximate the first fluid port and a floating valve seat assembly is disposed proximate the second fluid port. A first valve plug cooperates with the fixed valve seat assembly to open and close the first fluid port and a second valve lug cooperates with the floating valve seat assembly to open and close the second fluid port. The floating valve seat assembly includes a floating valve seat that is movable with respect to the fixed valve seat.

Hydraulic fluid release valve assemblies are described herein. The hydraulic fluid release valve assemblies may include a hydraulic unit base with a hydraulic fluid return channel and a hydraulic fluid release valve that is at least partially inserted in the hydraulic fluid return channel. The hydraulic fluid release valve assembly may further include a driving assembly to contact with the hydraulic fluid release valve to apply a pushing force on the hydraulic release valve to open the hydraulic fluid release valve, and an electrically powered driver connected to the driving assembly, the electrically powered driver, when actuated, causes the driving assembly to move to apply the pushing force to the hydraulic fluid release valve.