21/30368980 DC

This standard 21/30368980 DC BS ISO 21052. Restrained joint systems for ductile iron pipelines. Calculation rules for lengths to be restrained is classified in these ICS categories:

• 23.040.10 Iron and steel pipes

This document offers a method of computing the lengths of the pipe that must be restrained on each side (one side in case of Dead end) of the point of application of the thrust force.

The objective in designing a restrained joint thrust restraint system is to determine the length of pipe that must be restrained on each side of the focus of a thrust force. This method takes into account the outside diameter of the pipe, the design internal pressure (to estimate the thrust), depth of cover, the characteristics of the soil surrounding the pipe and trench backfilling methods for a worldwide usage. The characteristics of the restrained joint are not covered by this document but may also be considered to determine the restraining length using any appropriate method.

All types of restrained joint systems, with their operating pressure ratings of ductile iron pipelines complying with ISO 2531, ISO 7186 and ISO 16631 have been considered suitable for this method of computing.