ISO TS 10986:2021 pdf download.Plastics piping systems — Glass- reinforced thermosetting plastics (GRP) pipes — System design of above ground pipe and joint installations without end thrust
his document addresses the system design of pipe and joints of above ground installations without end-thrust as specified in systems standard ISO 23856. It is directed to pipelines with a minimum stiffness of SN 5000 laid in a straight line between thrust blocks. It is based on the safety concepts described in ISO TS 20656-1, with consequence class 2 (CC2) as default. For other consequence classes,certain details specified in this document can need to be modified. This document is directed to double bell coupling. However, much of the information can be adapted and utilized for other flexible joints systems.
This document does not cover fittings nor detailled engineering work like thrust blocks, support and anchor designs.
As installation is not included in the scope of this document and to assist system design, Annex A provides a pressure testing and inspection procedure. However, to ensure the use of clearly defined field test data in system design, Annex A can be used normatively by agreement between purchaser and supplier. An example of recording above ground joint deflection data is given in Annex B.
2 Normative references
There are no normative references in this document.
3? Terms? and? definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
4? Angular? deflection? of? joints
4.1 General
The angular deflection at flexible joints shall be controlled to avoid excessive loads on the pipeline and its supporting structures. Above ground installations do not benefit from the stabilizing support that is given by the soil in buried installations, and they are therefore more susceptible to problems of joint misalignment. For this reason, control and measurement of joint angular deflection is of great importantance. It is necessary to limit angular deflections to lower values than those normally permitted for buried applications.
There are two types of deflection to consider: pipe-to-pipe angular deflection and coupling-to-pipe deflection, as shown in Figure 1. Both need to be considered as coupling-to-pipe angular deflection can be larger than the pipe-to-pipe angular deflection.
For some designs of double socket joint the pipe can only move on one side of the coupling. In that case, the pipe-to-pipe angular deflection is equal to the coupling-to-pipe angular deflection on one side (see Figure 2). The manufacturer should advise which case will occur with their design of joint.
4.2? Effects? of? loads? on? joint? angular? deflection
The angular deflection is influenced by several factors in addition to the initial pipe installation, such as load-induced pipe deflections and support settlement.
Pipe deflections after inital installation are caused by forces produced by the weight of fluid in the pipe,external loads and pressure within the pipeline. These forces can produce significant pipe-to-coupling deflections which, if acting in a similar plane to the initial installation deflection, can result in the total deflection at the coupling exceeding the allowable limit. An example of this effect is shown in Figure A.3.
The initial pipe angular deflection therefore should be limited to allow for this effect to ensure that the total deflection does not exceed the maximum coupling deflection specification.
4.3? Measuring? deflections
The coupling-to-pipe angular deflection is measured as an angular offset, see Figure 3.
Coupling offsets L off,l and L off,r should be measured as follows:
Find the maximum and the minimum distance between the homeline and the face of the coupling along the circumference of the pipe. Subtract the minimum found value from the maximum found value.ISO TS 10986 pdf download.ISO TS 10986 pdf download
