ISO 21051:2020

Foreword

1 Scope

2 Normative references

3 Terms and definitions

4 Occupational safety and health requirements

5 Materials in contact with water intended for human consumption

6 Input control, transport, handling and storage of pipeline components and inspection

6.1 Input control

6.2 Transport, handling and storage and inspection of pipeline components

6.2.1 Transport

6.2.2 Handling

6.2.3 Storage

6.2.4 Inspection

7 Coating and lining repairs

7.1 General

7.2 Repair external coating

7.2.1 General

7.2.2 Repair procedure

7.3 Repair cement mortar lining

7.3.1 General

7.3.2 Repair procedure cement mortar lining

8 Cutting of pipes and ovality correction

8.1 Cutting of pipes

8.1.1 General

8.1.2 Pipe cutting tools

8.1.3 Chamfering of cut edge

8.1.4 Repair of damaged lining and coating

8.2 Ovality correction

9 Site preparation and pipe trenches

9.1 Trench width

9.2 Trench excavation and minimum depth of cover

9.2.1 General

9.2.2 Minimum depth of cover

9.2.3 Regulations

10 Pipeline protection

10.1 General

10.2 Site applied polyethyelene sleeving

11 Laying of pipes

11.1 Precautions at site before laying

11.1.1 General

11.1.2 Preparation before pipe laying and jointing

11.2 Construction of pipe trenches

11.2.1 General

11.2.2 Bedding

11.2.3 Trench types

11.2.4 Soil types

11.3 Safety, protection of property and structures

12 Push-in joints, jointing and anchoring

12.1 Preparations before jointing

12.2 Push-in joints

12.2.1 General

12.2.2 Push-in joint assembly for the pipes

12.2.3 Jointing of push-on fittings

12.2.4 Jointing of fittings by jointing tackle (assembler)

12.2.5 Jointing of fittings by winch method

12.2.6 Maximum joint deflection and laying length

12.2.7 Inspection of the joint

12.2.8 Dismantling of Joint

12.3 Mechanical joints

12.3.1 General

12.3.2 Mechanical joint assembly for pipes

12.4 Flanged Joints

12.4.1 General

12.4.2 Flange bolting tightening sequence

12.4.3 Maximum bolt tightening torque

13 Functional features and installation of valves

13.1 Installation of valves

13.1.1 General

13.1.2 Air valves

13.1.3 Scour valves or drain valves

13.1.4 Isolation valves

13.1.5 Hydrants

13.1.6 Surge limiting equipment

14 Restrained joints and thrust blocks

15 Cleaning, hydraulic testing and commissioning of pipeline and pipeline components

15.1 Cleaning

15.2 Hydraulic testing

16 Flushing and disinfection

17 Service connections

17.1 General

17.2 Conventional type service connection

17.3 External seal type connection

17.4 Saddle for ductile iron pipes for distribution network

18 Supporting pipes

18.1 General

18.2 Support for above ground installation

18.3 Maximum span for river crossing

18.4 Laying of ductile iron (DI) pipes in hilly terrain

18.4.1 General

18.4.2 Pipe line anchoring on slope

18.4.3 Basic precaution during trenching and bed preparation for pipes on slope

18.4.4 Additional precautions during laying in a hilly and rocky terrain

18.4.5 Precaution in snow bound areas

19 Railroad and highway crossings

Annex A (normative) Site applied polyethylene sleeving

Bibliography