Introduction:-
Today I will discussed about expansion loop, type of expansion loop, sizing of expansion loop, factor which decided the expansion loop, location of expansion loop on pipe rack and pipe trestles.
when many small bore or large bore pipe run through pipe rack or pipe trestles it is very logical to decided pipe loop .when pipe run through pipe rack having high temperature the piping engineer or stress engineer responsibility to make the pipe flexible by using elbow, z-bend, expansion loop.
expansion loop depend upon the various factor :
1.pipe size.
2.operating temperature.
3-Pipe material
smaller size pipe have more expansion in comparison of heavy pipe because smaller size pipe is more flexible in comparison of large bore pipe .
temperature is directly effect the thermal expansion in pipe .higher the temperature then higher the expansion loop .
expansion in pipe is different for different type of material.
Thermal expansion will occur between all fixed points in
the piping system. If the system has the same covering
height, natural fixed points will occur in the center of a line
section between two expansion elbows. Unequal covering
will cause the fixed point to be displaced due to varying
frictional forces, and if there is any doubt, the fixed point
should be set with an anchor. In all cases, this fixed point
should be considered when calculating expansion.
Guide line for expansion Loop:
- The expansion loop is usually located on the side of
the hottest line. - The expansion loop, as a rule, should be located in
the center of the distance between two anchors. - The height of the expansion loop is normally twice the
width. The exception to this rule occurs when more
than one line runs parallel in a common trench. The
dimensions of the loops for the additional line must be
increased to allow nesting of the loop.
expansion loop provide every 30 meter or 45 meter as per temperature and size of pipe .as shown in fig. expansion loop is provide between two anchor supports.
expansion loop is given as per below sequence:-
high temperature line is located at outer side and the medium temperature line the low temperature line is placed. the line which have more expansion then expansion is replaced by 3-D expansion loop.