PVC Pressure Pipe Standards

PVC Pressure Pipe Standards

Australian Standards for PVC pressure pipes cover composition, dimensions, performance and marking requirements for pipes, fittings and joints. Pipes are designated by their nominal size (DN) and their nominal pressure rating or class at 20°C (PN). Australian Standards generally cover more than one size range with different outside diameters. These are identified in the marking on the pipe and sometimes by colour. Special purpose colours for specific applications may also be used, such as purple for recycled water.

For a given diameter series and nominal size, the mean outside diameter is specified and the wall thickness increases with increasing pressure rating.

The standard effective length of PVC pipes is 6m although other lengths, up to 12m, may also be available.

Pipes are supplied with an integral socket for either solvent cement or rubber ring¹ jointing or as plain-ended pipes for jointing with couplings.

The following Australian Standards specify requirements for PVC pressure pipes

AS/NZS 1477 – PVC pipes and fittings for pressure applications

AS/NZS 1477 covers two size ranges of PVC-U pipes. Series 1 is a metric size range and Series 2 is compatible with the outside diameter of Australian cast and ductile iron pipes. Series 1 pipes are generally coloured white and Series 2 pipes are generally coloured light blue.

This standard covers Series 1 pipes in sizes from DN 10 upwards with solvent cement joints or rubber ring joints and Series 2 pipes from DN 100 with rubber ring joints.

AS/NZS 4441 – Oriented PVC (PVC-O) pipes for pressure applications

AS/NZS 4441 is an adoption of the International Standard ISO 16422 with some additional requirements for Australia and New Zealand. AS/NZS 4441 has specifications for two diameter series. These are:

• ISO series. These pipes are known as Supermain International pipes and fully comply with both AS/NZS 4441 and ISO 16422; and
• Series 2. These pipes are compatible with the Australian Cast/Ductile Iron pipe outside diameter series and are known as Supermain. Supermain pipes meet the material and performance requirements of both standards and the dimensional requirements of AS/NZS 4441.

Supermain Series 1 pipes for drinking water applications are coloured white. Supermain Series 2 pipes for drinking water applications are coloured light blue. Other colours may be used for different applications for both Series such as purple for recycled water and cream for pressure sewer pipes.

Both series are available in rubber ring joints only.

As Supermain pipes achieve their performance enhancement from molecular orientation, it is possible to vary the mechanical properties by changing the orientation level. AS4441 (Int) covers a range of PVC-O pipe materials, classified by their Minimum Required Strength or MRS value. The material class is related to the MRS as shown in the table below:

Material class for a given pipe can be identified by the marking on the pipe. Vinidex specialises in the higher material classes of PVC-O.

AS/NZS 4765 – Modified PVC (PVC-M) pipes for pressure applications

Series 1 (Vinidex Hydro™ Series 1) and Series 2 (Vinidex Hydro™ Series 2) PVC-M pressure pipes are covered by AS/NZS 4765. Series 1 pipes have either solvent cement joints or rubber ring joints. Series 2 pipes have rubber ring joints only. Sizes start from DN 100 for both series. Hydro Series 1 pipes for drinking water applications are coloured white. Hydro Series 2 pipes for drinking water applications are coloured light blue. Other colours may be used for different applications for both Series such as purple for recycled water and cream for pressure sewer pipes.

Selection of Pipe Diameter and Class

The pipe diameter and class of PVC pipes is selected by consideration of the required hydraulic capacity and the expected operating conditions. For determination of the flow capacity, it is the mean internal diameter (ID) or bore which is the significant dimension. The mean ID for pipes to Australian Standards is calculated as mean OD minus twice the mean wall thickness. See the product pages for relevant dimensions including the ID of PVC-U pipes.

Vinidex Supermain^® PVC-O Pipe Dimensions
Vinidex Hydro^® PVC-M Pipe Dimensions (Series 1)
Vinidex Hydro^® PVC-M Pipe Dimensions (Series 2)
Vinidex PVC-U SCJ Pipe Dimensions
Vinidex PVC-U RRJ Polydex^® Pipe Dimensions (Series 1)
Vinidex PVC-U RRJ Vinyl Iron^® Pipe Dimensions (Series 2)
Vinidex PVC Borecasing Pipe Dimensions

Australian Standards classify PVC pipe into pressure classes shown in the Table below. Note that not all of these classes apply to all product ranges. Consult the relevant standard for applicable classes. This classification is intended to provide a first order guide to the duty for which the pipes are intended. These working pressures incorporate a suitable factor of safety to ensure trouble free operation under average service conditions.

Maximum Working Pressure

There are, however, many factors which must be considered when determining the severity of service and the appropriate class of pipe. In some instances, standard factors of safety may be too conservative, in others too risky. The final choice is up to the designer in the light of his knowledge of his particular situation.

Amongst the factors to be considered are:

1. Operating pressure characteristics:
   a) Maximum steady state or static pressures.
   b) Dynamic conditions, frequency and magnitude of pressure variations due to system operation or demand variation.
2. Temperature: The stress capability of PVC is temperature dependent.
3. Other load conditions: Earth loads, traffic loads, bending stresses, installation loads, expansion and contraction stresses and other mechanical loads.
4. Service life required: For short-term projects, e.g. mining, a life of 5 to 15 years could be appropriate; for irrigation, possibly 15 to 30 years; for municipal water supplies, 30 to 100 years.
5. Factor of safety: Dependent largely on the likelihood and consequences of failure, and the number of unknowns. Basic factors of safety built into Australian Standards for PVC pipes are applied at the design point of 50 years. For PVC-U to AS/NZS 1477 the standard safety factor is 2.145, for PVC-O, it is 1.6 and for PVC-M it is 1.4. ²

For situations involving high costs of down-time and repair, a higher factor should be used.

 

Footnotes:

1. Current Australian Standard terminology is “elastomeric ring joint”, however the simpler term “rubber ring joint” is used throughout these pages.
2. For PVC-U, the safety factor is applied to the mean extrapolated stress whereas for PVC-O and PVC-M it is applied to the 97.5% lower confidence limit.