Abstract: Within an apparatus for storing a liquid, there is first included a storage tank. The storage tank has formed integral thereto and in fluid communication therewith a liquid inlet port and a liquid outlet port. The storage tank also has formed integral thereto and in fluid communication therewith a gas inlet port and a gas outlet port. Finally, the gas outlet port has connected thereto and in fluid communication therewith a floating plug valve. The floating plug valve comprises a first plug movably positioned over and sealing a first aperture within the floating plug valve such that a first weight of the first plug and a first area of the first aperture define an upper operating pressure of a gas introduced into the storage tank through the gas inlet port. The apparatus of the present invention also contemplates a floating plug valve employed within the apparatus of the present invention.

Abstract: An apparatus and a method for supplying uninterrupted gas by using an automatic switching gas supply system are provided. In the apparatus, a main gas supply source and at least one back-up gas supply source are provided which are connected by a plurality of conduits to a process tool. The conduits further include pressure regulators such that a gas pressure from the main gas supply source is always regulated at about 0.5 Kg/cm2˜1 Kg/cm2 higher than a gas pressure from the back-up gas supply source. The apparatus operates by pneumatic means so that no electric power is required. The apparatus further operates automatically by switching from the main gas supply source to the back-up gas supply source when the pressure drop in the main gas supply source exceeds the pressure differential that is preset in the system, e.g., between about 0.5 Kg/cm2 and about 1 Kg/cm2. Any other suitable range of pressure differential may also be used depending on the type of gases transported and the conduits used.

Abstract: An integrated check valve/strainer-filter assembly that combines a check valve with a strainer-filter assembly in a compact structure is provided. The novel assembly provides the benefits of floor space savings and low maintenance costs. A strainer-filter element may be mounted in a removable strainer-filter housing to provide easy access to the element for cleaning or replacement. The check valve may be installed at one of three desirable positions thus affording additional flexibility of the present invention novel apparatus.