Expansion Joint Design Notes - CAESAR II - Help

CAESAR II Users Guide

Language
Русский
Product
CAESAR II
Search by Category
Help
CAESAR II Version
12

It was common practice in the expansion joint industry to design expansion joint bellows and hardware (restraints) for the system pressure, and pressure thrust only. Generally, no consideration was given to the system deadweight or thermal forces. This poor practice was tolerated before the wide-spread use of piping analysis software because:

  • The deadweight and thermal forces are normally small compared to the pressure and pressure thrust.

  • Designers laid out expansion joints so that the thermal forces were very low and therefore not significant.

  • The allowable stresses used in hardware designs have a significant safety factor.

The forces and moments generally were not known. Today, when an expansion joint is modeled, it is recommended that al information relating to the joint be submitted to the expansion joint manufacturer. This is especially true of the forces and moments resulting from the operating loads, such as deadweight, thermal forces, and operating deflections. Better evaluations of the loading conditions on the bellows and hardware simply help the manufacturer make sure that his design is suited for the intended installation and service.