Expansion joints fasteners

Parmley, R. O., ed. 1997. Standard Handbook of Fastening and Joining, 3rd ed. New York McGraw-Hill. This work addresses the multitude of processes by which materials or components can be connected. Included are fasteners, such as threads pins rings pipe connections expansion joints various types of welding concrete, lumber, and steel connections locks electrical connections adhesives rivets rope and cable connections shafts and couples seals and even rope splicing and tying. 

Thermal expansion and the resultant pipe stresses must be considered in any piping system design. For example, if the temperature changes from 50 to 600°F, the increase in length would be 4.9 in. per 100 ft for steel pipe and 7.3 in. per 100 ft for brass pipe. This amount of thermal expansion could easily cause a pipe or wall to buckle if the pipe were fastened firmly at each end with no allowances for expansion. The necessary flexibility for the piping system can be provided by the use of expansion loops, changes in direction, bellows joints, slip joints, and other devices. 

The major corrosion product identified in corroded fuselage joints is hydrated alumina, A1(0H)3, with a particularly high volume expansion (6.0) relative to aluminum (0.9). Such a buildup of voluminous corrosion products can result in an undesirable increase in stress levels near the critical fastener holes and subsequent fracture because of the high tensile stresses resulting from the pillowing. ... 

Another important point to consider when designing joints for self-fastening is the thermal coefficient of expansion. For example, most metals have a thermal expansion co-... 

Aluminum and stainless fasteners expand and contract when exposed to temperature extremes, as in aircraft applications. In carbon-fiber composites, contraction and expansion of such fasteners can cause changes in clamping load. Pressure within the joint is often critical. 

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