Installation of pipelines

​General 6.7.1

Laying, jointing and embedment of pipes must be done in accordance with the following relevant standards, drawings and this specification.

 

Standard​ Description​

AS/NZS 2032-2006​

Code of Practice for installation of UPVC pipe systems

AS/NZS 2033-2008​

Installation of polyethylene pipe systems​

AS 2566.2-2002​

Buried flexible pipelines - Installation​

AS 3690-2009​

Installation of ABS pipe systems​

AS 3725-2007​

Design for installation of buried concrete pipes​

AS 4058-2007​

Pre-cast concrete pipes (pressure and non-pressure)​

AS 4139-2003​

Fibre-reinforced concrete pipes and fittings​

Table 14

The contractor must keep the excavations free from water until each pipe has been laid, jointed, embedded and sufficient backfill material is over the pipe to prevent pipe flotation.

Foundation 6.7.2

The foundation must be prepared to meet the requirement of AS 3725-2007. For the purpose of this Specification, the foundation is the naturally occurring or imported material beneath the support or special base.

Inspection of pipeline components 6.7.3

Damage and flaws

The pipeline components must be checked for damage and flaws immediately before installation.

Distortion of HDPE pipe

HDPE pipes must be checked for out of round at the ends and bowing along their lengths, at least two days before the pipes are laid to allow for correction.

Pipes are considered out of round if the horizontal diameter varies from the vertical diameter by more than 3 per cent.

Laying of pipes 6.7.4

General

Pipes must be laid in accordance with AS 3600-2009.

If a flexible wall pipe is out of round, the larger diameter must be laid vertically. If it has a bowed length, the bow must be laid horizontally.

Pipe-laying tolerances

Pipelines must be constructed to the tolerances described below, unless otherwise specified on the Drawings.

Plan

The departure at any point from the position indicated on the Drawings must not exceed 30 millimetres.

Level

If reduced levels are specified on the Drawings, the pipeline must not deviate from its specified level by more than 10 millimetres higher or 25 mm lower.

Grade

The grade at any part of a pipeline mustn't be more than four per cent flatter than specified on the Drawings. Backfall at any point isn't permitted.

Pipe cutting

Pipes must be cut square to the barrel of the pipe with a total deviation of not more than five millimetres. Jagged edges must be removed. Cut edges of PVC and PE pipes must be bevelled in accordance with the manufacturer's instructions.

Jointing of pipes 6.7.5

General

Pipes and fittings must be jointed in accordance with AS 3600-2009, and the manufacturer's instructions.

Reinforced concrete pipes

All jointing cavities in interlocking joint pipes must be thoroughly cleaned, dried and neatly filled with a cement-sand mortar mixed in proportion of one part cement to three parts sand by volume. The joint must be wiped smooth before the mortar has set to finish flush with the surface of both pipes.

If there's a gap of 15 millimetres or greater around more than half the circumference of the pipe, the joint must be bandaged in accordance with our Drawing 7251/08/420.

Where rubber ring joint pipes must be installed, the rubber ring must roll evenly and be correctly positioned in the joint, otherwise the pipe must be withdrawn and the joint remade. Rubber rings must then be inspected.

Make-up pipe sections

If inlet pipes are to be connected and splay-ended pipes for curves haven't been specified, concrete make-up sections must be provided between the ends of pipes.

The make-up sections must be constructed as shown on the Drawings.

Fibre-reinforced concrete pipes

All FRC pipes shall be rubber ring jointed.

Embedment of pipes 6.7.6

Embedment is to be in accordance with AS 3725-2007 and Drawing 7251/8/301.

Trenches and shafts

Pipes must be embedded in accordance with the Drawings. Temporary trench support shields in the pipe embedment zone must be lifted above each layer of embedment before the compaction of each layer.

Bored lines

The annular space around the pipes on bored lines must be filled with a sand-lime-cement grout as specified in Type C (slurry) and Drives, tunnels, shafts and bores.

Drives and tunnels

Pipelines must be embedded to 0.7 of the pipe external diameter above the bottom of the pipe, as specified for trenches and shafts. The remainder of the tunnel or drive must be refilled as for backfill of a drive and tunnel in Drives, tunnels, shafts and bores.

 

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