Joints seal-ring

The immediate cause was failure of the ring joint seal on the solid rocket booster. Yet, a root-cause analysis revealed a much more complex scenario. According to information published after the investigation, post flight evidence from as far back as early 1984 showed that the joint seals were failing to meet design specifications. 

FIG. 10-141 Seal -ring joint. Coutiesy of Gray Tool Co.)... 

Photolysis Reactors and Ultraviolet Sources. For 253.7-m/ irradiation, a modified irradiation apparatus purchased from Delmar Co. was used. The reactor was a 2-necked, 500-ml., round-bottomed flask. One neck was an O-ring joint, and the other was a 24/40 joint. A 4- X 1-inch coiled low pressure mercury quartz lamp was placed inside the flask through the O-ring neck, and the joint was sealed with removable O-rings. The reactor was connected directly to the mass spectrometer by the 24/40 joint. The samples were placed inside the flask and irradiated internally. The O-ring was shielded from direct radiation so as not to induce degradation. The estimated output of the lamp was 30 watts, and the ambient temperature within the reactor during irradiation was 70°C. 

Fig. 1.21. Typical assemblies of Schlenk ware. Commercial apparatus is illustrated similar apparatus with O-ring joints in place of standard taper joints is preferred by the authors. (

G. Variations in Schlenk Ware. A large number of modifications of the basic Schlenk ware are in use. The double-ended filter is a commonly used variant of the standard Schlenk filter. The particular unit illustrated in Fig. 1.29 is equipped with O-ring joints rather than standard taper joints. (See Chapter 8 for a discussion of joints and O-ring materials.) Either conventional or modified O-ring joints, such as the Fischer and Porter Co. Solv-Seals, have several advantages over standard taper joints for Schlenk apparatus these O-joints are more resistant to solvents than the conventional standard taper ware, the O-joints are more readily clamped together, and, unlike standard taper joints, the two halves... 

Fig. 9.19. Solvent storage container. Solvent is distilled in through the sidearm, which is then sealed off under vacuum. The container is attached to the vacuum line through a 18/9 ball joint or O-ring joint.

O-rings are commonly found on mechanical vacuum pumps, rotary valves, and O-ring joints. O-rings are used to separate environments. If an O-ring is attacked by the chemicals from one or both of these separated environments and fails, it will lose its protective sealing capabilities. Similarly, if an O-ring is left in a chemically destructive environment, it may become dysfunctional without ever having been used. 

Ring joint flanges seem to provide better seals than raised face flanges but getting valves and flanges apart can be difficult. 

Kalrez O-rings are available from Service Seal and Packing, Inc., 277 Fairfield Road, Fairfield, NJ 07006 (201-575-4277) Size Oil (Kontes 8 mm valve seat size), 15.80. Size 116 (15 mm 0-ring joint size), 27.90. 

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