When structures get hot, they expand. This expansion has to be accommodated within the design of the structure. Just as bridges and buildings expand and contract as a result of the changes in ambient temperature, pipelines expand and contract as the temperature of the fluid they are transporting changes as well as the changes in the weather outside the pipeline.
Pipelines will expand and contract by an amount determined by the shape and coefficient of thermal expansion of the material used in building them. If these pipelines are not allowed to expand and contract freely, severe stresses get induced which could lead to failure or overloading.
An extremely effective way of accommodating expansion in pipelines is to allow one item to move in relation to another. This can be achieved by using low friction slide bearings to separate the expanding item from the support structure.
At the heart of these slide bearing is a graphite plugged self lubricating bronze plate. The bronze plate acts as the bearing pad for the pipe support slide bearing. Piping system slide bearings consist of a graphite filled bronze bearing plate with an upper and lower slide plate component. Slide plates are usually arranged in a “sandwich” formation. The lower slide plate may also be welded to a stationary support, which grounds the plate. While the other plate is attached to the moving component directly. As the system moves, friction is transferred at the intersection of the two plates.
Bronze plates filled with graphite solid lubricant plugs can handle temperatures up to 500 degrees Fahrenheit. The bronze plates are also suited for high pressure systems. Bronze slide plates offer the following additional advantages:
– Capable of operating completely dry, no lubrication required.
– Able to withstand a wide range of environmental conditions.
– Resistant to a wide range of organic and inorganic chemicals.
– Can tolerate some embedment of small particles without causing failure.
– Long and maintenance free life.