Abstract: Apparatus for providing a simulated space environment for the testing of articles under low temperature conditions comprising a liquid nitrogen head tank, liquid nitrogen subcooler pumps, a liquid nitrogen subcooler coil, a liquid nitrogen head tank makeup pumps, a low pressure liquid nitrogen storage tank, a high pressure liquid nitrogen storage tank, a liquid nitrogen transfer pump, a vacuum chamber and thermal simulation heat exchanger shrouds contained within the vacuum chamber. Appropriate internal and external piping connects these components so that the apparatus can be operated both in a subcooled pressurized closed loop system as well as in a gravity convection system. While liquid nitrogen in this apparatus will produce a stable uniform temperature of -297.degree. F. within the shroud containing the article to be tested, other liquids with similar low temperature characteristics may be used.

Abstract: An elevated water storage facility includes a fluted pillar which is divided into a plurality of levels so the facility is multi-purpose. One embodiment of the facility includes an outer wall surrounding the pillar.

Abstract: A multi-purpose elevated water storage facility includes a water tank which has a fluted portion. The pillar supporting the tank can also be fluted. A box girder can be used to connect the tank fluted portion to the pillar and to a bottom portion of the tank, and additional usable space can be defined above a water storage portion of the tank.

Abstract: A joint for use with a space frame for connecting a plurality of struts together. The joint permits dome fabrication and erection with essentially no field bolting required. A central hub is included in the joint for resisting forces transmitted to the joint by dome struts.

Abstract: An improved removable condensate collector for elevated water storage facilities includes a membrane attached to the walls of such elevated water storage facility and positioned to prevent condensate from falling onto structures located at or near the bottom of the facility from a water storage container located at or near the top of the facility. The membrane can be frusto-conical in shape with the apex thereof located above or below the base, or can be horizontally disposed within the facility. The membrane is strengthened to support collected water thereon, until evaporation and ventilation remove that water from the storage facility.

Abstract: A tank is constructed and formwork apparatus is attached to that formed tank. The formwork apparatus is used to construct a tank supporting wall and jacking mechanisms included in that formwork apparatus lift the tank as the support wall is being formed so that the tank is carried upwardly by and on the supporting wall as that wall is constructed. The formwork is preferably slipforms.

Abstract: A seal joining a vacuum vessel head to a shell includes a flange on the head and a flange on the shell with a seal ring interposed therebetween. Spacers transfer the weight of the head and the vacuum load in the vessel to the seal ring. A sealing skirt attaches to the head flange and to the seal ring.

Abstract: A secondary seal for a floating roof product storage tank has a cross-sectional shape substantially that of a right triangle. The hypotenuse of that right triangle contacts the primary seal and one leg of the seal extends outwardly of the roof rim. The seal is supported to extend downwardly from the rim and is deformable.

Abstract: A spill condition venting system for a double containment tank includes a control system for controlling, in the event of a spill or an overflow of fluid into the annulus of such double containment tank, the flow of stored fluid into and out of the annulus and for controlling vapor resulting from such spill.

Abstract: A removable condensate collector for elevated water storage facilities includes a membrane attached to the walls of such elevated water storage facility and positioned to prevent condensate from falling onto structures located at or near the bottom of the facility from a water storage container located at or near the top of the facility. The membrane can be frusto-conical in shape with the apex thereof located above or below the base, or can be horizontally disposed within the facility.

Abstract: Large openings in a storage tank wall caused by cracks appearing therein are prevented by surrounding such wall with a plurality of rings which are spaced apart from the wall to be structurally independent of that wall. Such structurally independent rings are not susceptible to stressing forces exerted on the wall.

Abstract: A roof strut permits easy attachment of roof covering material thereto. The strut has a channel defined therein and a clamping bar is positioned within the channel to sandwich roof covering material between that bar and the strut to form a gasketless seal.