AS/NZS 2566.2:2002 - What is it and why do you need it?
If you are involved in the design, installation, or maintenance of buried flexible pipelines, you may have heard of AS/NZS 2566.2:2002. This is a joint Australian/New Zealand standard that specifies the requirements for the installation, field testing, and commissioning of buried flexible pipelines with structural design in accordance with AS/NZS 2566.1. These pipelines rely primarily upon side support to resist vertical loads without excessive deformation by adopting an elliptical shape.
But what are the benefits of using this standard for buried flexible pipelines? And how does it differ from other standards or pipe types? In this article, we will answer these questions and more, so you can make informed decisions about your pipeline projects.
as nzs 2566.2 free download
Introduction
Buried flexible pipelines are pipes that can deform under external loads without losing their structural integrity or hydraulic capacity. They are commonly used for applications such as water supply, sewerage, drainage, irrigation, gas distribution, and cable protection. Flexible pipelines can be made of various materials, such as plastic, metallic, or composite.
AS/NZS 2566.2:2002 is a standard that provides guidance on how to install buried flexible pipelines in a safe and effective manner. It covers aspects such as site preparation, trench excavation, bedding and backfilling, pipe laying and joining, thrust restraint, trenchless installation methods, field testing, and commissioning.
Some of the benefits of using AS/NZS 2566.2:2002 for buried flexible pipelines are:
It ensures that the pipeline is installed in accordance with the structural design criteria specified in AS/NZS 2566.1.
It minimizes the risk of damage to the pipeline during installation or service.
It optimizes the performance and durability of the pipeline under various loading and environmental conditions.
It facilitates quality control and inspection of the pipeline installation.
It complies with the relevant regulatory and contractual requirements.
However, not all pipelines are flexible. Some pipelines are rigid, meaning that they do not deform significantly under external loads. They rely on their inherent strength and stiffness to resist loads without cracking or collapsing. Rigid pipelines are typically made of concrete or clay.
The design and installation requirements for rigid and flexible pipelines are quite different. For example:
Rigid pipelines require more careful handling and protection during installation to avoid damage.
Rigid pipelines need more precise alignment and leveling to ensure proper jointing and sealing.
Rigid pipelines need more rigid bedding and backfilling materials to support their weight and prevent differential settlement.
Flexible pipelines require more careful selection and compaction of bedding and backfilling materials to provide adequate side support and load transfer.
Flexible pipelines need more allowance for thermal expansion and contraction due to temperature changes.
Flexible pipelines need more attention to thrust restraint at bends, tees, reducers, valves, etc., to prevent pipe movement or separation.
Installation Installation requirements
The installation of buried flexible pipelines according to AS/NZS 2566.2:2002 involves several steps, such as site preparation, trench excavation, bedding and backfilling, pipe laying and joining, thrust restraint, trenchless installation methods, field testing, and commissioning. Each step has its own specific requirements that need to be followed to ensure a successful installation.
Site preparation
Before starting the installation, the site should be prepared to provide a safe and suitable working environment. This includes:
Obtaining all necessary permits and approvals from the relevant authorities.
Identifying and locating all existing underground services and utilities, such as water, gas, electricity, telecommunications, etc., and marking them clearly on the ground.
Removing any obstacles or hazards that may interfere with the installation, such as trees, rocks, debris, etc.
Establishing access routes and storage areas for the equipment and materials.
Setting up traffic control and safety measures to protect the workers and the public.
Trench excavation
The trench excavation should be done in accordance with the design specifications and drawings. The trench should have adequate width, depth, and length to accommodate the pipe size, jointing method, bedding material, backfill material, and compaction equipment. The trench should also have sufficient clearance from other underground services and utilities.
The trench walls should be stable and safe to prevent collapse or cave-in. If necessary, shoring or bracing systems should be used to support the trench walls. The trench bottom should be smooth and level to avoid uneven settlement or stress concentration on the pipe. Any soft or unsuitable soil should be removed and replaced with suitable material.
Bedding and backfilling
The bedding and backfilling materials are crucial for providing side support and load transfer for the buried flexible pipeline. They should be selected and placed in accordance with AS/NZS 2566.2:2002 and the manufacturer's recommendations. The bedding material should have adequate strength, stiffness, durability, permeability, and compatibility with the pipe material. The backfill material should have similar properties as the bedding material, as well as good compaction characteristics.
The bedding layer should be placed on the trench bottom with a minimum thickness of 100 mm or 10% of the pipe diameter, whichever is greater. The bedding layer should be compacted to at least 90% of the maximum dry density (MDD) as determined by AS 1289.5.4.1. The pipe should be laid on the bedding layer with proper alignment and grade. The haunching layer should be placed around the pipe up to 75% of the pipe diameter or 300 mm above the crown of the pipe, whichever is less. The haunching layer should be compacted to at least 95% of the MDD as determined by AS 1289.5.4.1. The initial backfill layer should be placed above the haunching layer up to 300 mm above the crown of the pipe. The initial backfill layer should be compacted to at least 90% of the MDD as determined by AS 1289.5.4.1. The final backfill layer should be placed above the initial backfill layer up to the ground surface or as specified in the design. The final backfill layer should be compacted to at least 85% of the MDD as determined by AS 1289.5.4.1.
The compaction of the bedding and backfilling materials should be done using suitable equipment and methods that do not damage or displace the pipe. The compaction should be verified by field density tests or other approved methods.
Pipe laying and joining
The pipe laying and joining should be done in accordance with AS/NZS 2566.2:2002 and the manufacturer's instructions. The pipe laying should start from the lowest point of the pipeline and proceed uphill. The pipe should be handled carefully to avoid damage or contamination. The pipe ends should be inspected for any defects or foreign matter before joining.
The pipe joining method depends on the type and material of the pipe. For example:
Plastic pipes can be joined by various methods, such as solvent cementing, heat fusion welding, electrofusion welding, mechanical couplings, or rubber ring joints.
Metallic pipes can be joined by methods such as welding, brazing, soldering, flanging, threading, or mechanical couplings.
Composite pipes can be joined by methods such as those used for plastic or metallic pipes, depending on the composition and properties of the pipe.
The pipe joints should be watertight, airtight, and resistant to corrosion, abrasion, and stress. The pipe joints should be tested for leakage and integrity before covering with backfill material.
Thrust restraint
Thrust restraint is the method of preventing pipe movement or separation at changes in direction, size, or pressure in the pipeline. Thrust restraint can be achieved by various means, such as thrust blocks, anchors, tie rods, harnesses, or mechanical joints.
AS/NZS 2566.2:2002 provides guidance on how to design and install thrust restraint systems for buried flexible pipelines. The thrust restraint system should be able to withstand the maximum thrust force generated by the internal pressure and external loads on the pipeline. The thrust restraint system should also be compatible with the pipe material and jointing method.
Trenchless installation methods
Trenchless installation methods are techniques of installing buried flexible pipelines without digging a continuous trench along the pipeline route. Trenchless installation methods can reduce the environmental impact, cost, and time of the installation. However, they also require more careful planning, design, and execution to ensure a successful installation.
AS/NZS 2566.2:2002 covers two main types of trenchless installation methods for buried flexible pipelines: horizontal directional drilling (HDD) and pipe bursting. HDD is a method of installing a pipe by drilling a pilot hole along the desired pipeline route and then pulling the pipe through the hole. Pipe bursting is a method of replacing an existing pipe by breaking it with a bursting head and pulling a new pipe through the cavity.
Both HDD and pipe bursting have their own advantages and disadvantages, depending on factors such as soil conditions, pipe size and material, existing services and utilities, access points, etc. AS/NZS 2566.2:2002 provides guidance on how to select, design, and perform HDD and pipe bursting for buried flexible pipelines.
Field testing and commissioning
Field testing and commissioning are the final steps of installing buried flexible pipelines. They are done to verify that the pipeline is installed correctly and meets the design specifications and performance requirements.
AS/NZS 2566.2:2002 specifies the methods and procedures for conducting field testing and commissioning of buried flexible pipelines. The field testing includes hydrostatic pressure testing, pneumatic pressure testing, vacuum testing, leakage testing, deflection testing, alignment testing, etc. The commissioning includes flushing, cleaning, disinfection, purging, etc.
The field testing and commissioning should be done in accordance with AS/NZS 2566.2:2002 and the manufacturer's recommendations. The results of the field testing and commissioning should be recorded and reported to the relevant parties.
Comparison with other standards
AS/NZS 2566.2:2002 is not the only standard for buried flexible pipelines in the world. There are other standards that have similar or different requirements for the installation of buried flexible pipelines, such as ASTM (American Society for Testing and Materials), ISO (International Organization for Standardization), or EN (European Committee for Standardization).
Some of the main differences between AS/NZS 2566.2:2002 and other standards are:
Standard
Difference
ASTM D2321
This standard covers the installation of thermoplastic pipes such as PVC (polyvinyl chloride) or PE (polyethylene) in non-pressure applications such as drainage or sewerage. It has similar requirements as AS/NZS 2566.2:2002 for site preparation, trench excavation, bedding and backfilling, pipe laying and joining, thrust restraint, field testing, etc., but it does not cover metallic or composite pipes or trenchless installation methods.
ISO 21138
This standard covers the installation of structured-wall plastic pipes such as HDPE (high-density polyethylene) or PP (polypropylene) in non-pressure applications such as drainage or sewerage. It has similar requirements as AS/NZS 2566.2:2002 for site preparation, trench excavation, bedding and backfilling, pipe laying and joining, thrust restraint, field testing, etc., but it does not cover metallic or composite pipes or trenchless installation methods.
EN 1610
This standard covers the installation of plastic and metal pipes in non-pressure applications such as drainage or sewerage. It has similar requirements as AS/NZS 2566.2:2002 for site preparation, trench excavation, bedding and backfilling, pipe laying and joining, thrust restraint, field testing, etc., but it also covers trenchless installation methods such as HDD and pipe bursting.
The advantages of using AS/NZS 2566.2:2002 over other standards are:
It is a joint Australian/New Zealand standard that reflects the local conditions and practices.
It covers a wide range of pipe materials and types, such as plastic, metallic, or composite.
It provides detailed guidance on how to design and install thrust restraint systems for buried flexible pipelines.
It is compatible with AS/NZS 2566.1, which specifies the structural design criteria for buried flexible pipelines.
The disadvantages of using AS/NZS 2566.2:2002 over other standards are:
It may not be recognized or accepted by some international clients or contractors.
It may not be updated as frequently or comprehensively as other standards.
It may not cover some specific aspects or issues that are addressed by other standards.
Conclusion
Buried flexible pipelines are a versatile and cost-effective option for various applications such as water supply, sewerage, drainage, irrigation, gas distribution, and cable protection. They can deform under external loads without losing their structural integrity or hydraulic capacity. However, they also require proper installation to ensure their performance and durability.
AS/NZS 2566.2:2002 is a joint Australian/New Zealand standard that specifies the requirements for the installation, field testing, and commissioning of buried flexible pipelines with structural design in accordance with AS/NZS 2566.1. It covers aspects such as site preparation, trench excavation, bedding and backfilling, pipe laying and joining, thrust restraint, trenchless installation methods, etc. It provides guidance on how to install buried flexible pipelines in a safe and effective manner.
AS/NZS 2566.2:2002 has some advantages and disadvantages compared to other standards for buried flexible pipelines, such as ASTM, ISO, or EN. It is important to understand the differences and similarities between these standards and choose the most suitable one for your project.
FAQs
Here are some frequently asked questions related to the topic of this article:
Q: How can I get a copy of AS/NZS 2566.2:2002?
A: You can purchase a copy of AS/NZS 2566.2:2002 from the official websites of Standards Australia or Standards New Zealand. You can also access it online through some subscription-based services such as SAI Global or Techstreet.
Q: What are some examples of buried flexible pipelines?
A: Some examples of buried flexible pipelines are:
PVC pipes for water supply or sewerage
PE pipes for gas distribution or irrigation
Ductile iron pipes for water supply or sewerage
Steel pipes for oil or gas transmission
Fiberglass pipes for chemical or industrial applications
Q: What are some common problems or challenges with buried flexible pipelines?
A: Some common problems or challenges with buried flexible pipelines are:
Pipe damage or failure due to improper handling, installation, testing, or maintenance
Pipe movement or separation due to inadequate thrust restraint or soil support
Pipe leakage due to defective joints or fittings
Pipe corrosion due to aggressive soil or water conditions
Pipe degradation due to ultraviolet radiation or thermal cycling
Q: How can I prevent or solve these problems?
A: You can prevent or solve these problems by following the best practices and recommendations provided by AS/NZS 2566.2:2002 and the manufacturer's instructions. You can also consult with qualified engineers or contractors who have experience and expertise in buried flexible pipeline installation.
Q: Where can I find more information about buried flexible pipelines?
A: You can find more information about buried flexible pipelines from various sources, such as: You can find more information about buried flexible pipelines from various sources, such as:
[ASCE Library](^1^), which offers books, journals, conference proceedings, and standards on civil engineering topics, including buried flexible steel pipe design and structural analysis.
[ResearchGate](^2^), which is a social network for researchers and academics, where you can access and share publications, datasets, and projects related to buried flexible pipes.
[PDF Document](^3^), which is a website that provides free access to various PDF documents, such as a presentation on buried flexible pipelines by Geoffrey D Stone.
These sources can help you learn more about the theory, practice, and challenges of buried flexible pipeline installation.
I hope you enjoyed reading this article and found it useful. If you have any questions or feedback, please feel free to contact me. I'm happy to help. 44f88ac181
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