Hanger Between Two Pipes - CAESAR II - Reference Data

CAESAR II Applications Guide

PPMProduct
CAESAR II
PPMCategory_custom
Reference Data
Version_CAESAR
12

A pipe crossing overhead supports part of the weight of the lower pipe. The node on the pipe passing overhead is typed into the Hanger Auxiliary Data tab as the CNode.

When using hangers with connecting nodes to design springs, be particularly careful that CAESAR II’s design hot load is accurate. To find the hot load, CAESAR II puts a rigid element between the pipe node and the support node (which may be another pipe node as in the example below), and runs a weight case. If both nodes are expected to deflect in the weight run, then the hanger weight loads are distributed to other parts of the piping system and not to the hanger. In this case, you may have to estimate the loads on the hanger in an independent run, and then manually type the operating load on the particular spring hanger with the connecting node.

If zero-load constant-effort supports are designed for a spring location with a connecting node, switch the hanger node and the connecting node. In this situation, the pipe node tends to deflect downward in the weight run less than the connecting node. To CAESAR II, this looks like the connecting node is pushing down on the hanger node, thus “holding the pipe down.” Switching the hanger node and the hanger-connecting node eliminates this problem.

You must first disable the Connect Geometry Through CNodes configuration option to avoid plot and geometry errors. For more information, see "Configuration and Environment" in the CAESAR II User's Guide.

The pipe at 65 is supported by a spring hanger by the pipe at 470.