Constant load spring supports are fittings that are mounted external to the pipe and perform the function of supporting the weight of the pipe allowing its vertical movement, caused by thermal expansion.
The loads corresponding to the pipe are absorbed and transferred in a constant manner along the entire movement path, without significant deviations.
Significant deflections would act as additional detrimental and uncontrolled loads on the system. In such a case, the anchor points would be particularly endangered, due to forces and moments in excess of those permissible. These constant load spring hangers have proven their efficiency under all operating conditions. Their unique operating principle based on the parallelogram of forces is patented worldwide and is a decisive factor in their choice.
The Lisega constant load spring support is designed to absorb vertical movements up to 750 mm. It can be mounted as a pendant or as a single or double pedestal.
CONSTANT SPRING SUPPORT
With constant load spring supports, the reaction generated by the spring to the connected equipment or structures is zero. Their efficiency is very high and they should be used at critical points of the line.
They are used in points of the line subject to vertical movement due to thermal expansion where the use of rigid supports is illogical, since in operation the support is lifted. Their most common use is to protect the transmission of stresses or tensions in critical equipment such as steam turbines, gas turbines, superheaters, separators or steam reduction stations.
For variable load spring supports, MSS SP-58-2018 specifies a maximum of 25% spring load variation during operation. If greater variability is expected, constant load spring supports are used.
The tolerance in this case should not exceed 6% as per standard. The bracket design allows constant strength to be maintained under different loads.
The load range varies from 16 to 41270 KgF with displacements from 38 to 508 mm. They are manufactured in accordance with standards such as MSS, ANSI and ASME.
The correct selection of the supports is defined by a previous flexibility study (stress analysis), in which the forces and movements at the support points are calculated. Lisega offers, free of charge, the LICAD® software, always available on the Lisega website, this software facilitates the selection of each support and the necessary accessories for its assembly, always based on the ASME.