Sealed construction, nickel systems

Various types of cell and battery design and construction can be used in the nickel-zinc battery system. Cells have been built in both prismatic and cylindrical designs and both vented and sealed designs. However, most current commercial applications require the use of a sealed, maintenance-free design. A typical sealed prismatic battery is shown in Fig. 31.7. This type of construction can be used for a wide range of cell sizes and is particularly suited to larger capacity batteries (e.g. greater than 10 Ampere-hours). 

The problem of containing fluorine in tanks, lines, valves, pumps, and other parts of the rocket feed system has two aspects. These are the selection of materials and the proper techniques in using materials. There are a number of metals which are satisfactory for the construction of parts. Nickel, monel, stainless steel, copper, and brass can all be used successfully. For such things as seals and packings for joints, valves, and pumps, however, the situation is not satisfactory. The usual soft materials which are used for this service (such as asbestos) all react vigorously with fluorine, Fluorinated plastics are the only materials available and they have serious limitations to their use. For instance... 

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