Pipe Guide Spacing
December 27th, 2010
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Pipe guides are necessary to assure that the thermal expansion of the pipeline is properly directed into the expansion joint and to prevent buckling of the line. Additional guides located adjacent to the expansion joint are necessary because of the inherent flexibility of the bellows and the compressive loading on the pipe caused by the pressure thrust of the expansion joint.
The first guide must be located within a distance of four pipe diameters from the expansion joint and the second guide within fourteen pipe diameters of the first guide. Additional guides should be located in accordance with the Pipe Guide Spacing Chart shown below for standard weight carbon steel pipe or calculated from the following formula:
Where L = maximum intermediate guide space, (feet)
E = modulus of elasticity of pipe material, (psi)
I = moment of inertia of pipe, (in4)
P = design pressure, (psig)
= bellows spring rate, (lb/in)
a = bellows effective area, (in 2)
= bellows spring rate, (lb/in)
= axial stroke of bellows, (in)
Note: When a bellows is compressed in operation, use
when extended, use
