Polynex HDPE Pipe
Since Australian pipe manufacture began in the 1950s, polyethylene pipes have been recognised for their outstanding physical properties and chemical resistance.
Now, enormous leaps in technology have rendered polyethylene the material of choice for engineers in the 21st century, and for mega-cities such as New York and London.
POLYNEX High-Density Polyethylene pipes (HDPE) are formed using a unique double-wall ‘I’beam profiling, resulting in compression strengths up to 8kN/m2. Resistant to fatigue and corrosion, the HDPE pipe has an estimated asset life in excess of 100 years.
HDPE pipes have been utilised in a range of applications, from culverts to sewerage, manholes to below-ground water storage. Pipe sizes range from DN500 to DN3000, making implementation only as limited as your ingenuity.
Polynex realises that when it comes to large scale, long-term investment projects, details are at the core of success.
Used for Polynex pipe manufacture is Centrene ® HDF193B high-density polyethylene, a black, high molecular weight bimodal PE100 HDPE. It is a high performance resin for use in pressure pipes and non-pressure pipes, where service life to 100 years is required. HDF193B offers a balance of excellent processing characteristics along with outstanding toughness, chemical resistance and slow-crack growth resistance. HDF193B also demonstrates tremendous resistance to the effects of ultra-violet light exposure in outdoor applications, due to well dispersed carbon black.
Centrene ® HDF193B is suitable for extrusion into a full range of pipes, where high density, PE 100 type resins are required. In particular, a broad processing window and good sag resistance enables the extrusion of larger bore, thick wall pipe. HDF193B is suitable for use in the transport of a wide range of fluids for industrial, rural and mining applications, including potable water.
HDF193B complies to AS/NZS 4131 2010 for PE100 type compounds. It is intended to be used in pipes conforming to AS/NZS 4130.
Scale and Sediment
Sediment and scale do not readily adhere to or bond with HDPE due to the inert nature of polyethylene. This prevents the occurrence of build-up, resulting in maintained long-term flow characteristics.
Durability is measured by a number of properties, such as the ability to resist abrasion, corrosion, degradation and other service conditions.
The longevity of pipe infrastructure is dependent on the physical and chemical characteristics of the pipe, and on the environment to which it is exposed. Unlike concrete, HDPE will not spall, crumble or crack. Protective coatings, linings and other palliative measures, which being superficially acceptable as a short-term solution, are at risk of delamination, erosion and cracking.
Many abrasion testing methods have been developed, the most commonly acknowledged being the Darmstadt abrasion test. A test specimen one (1) meter long is tilted back and forth with a frequency of 21.6 cycles/minute. The specimen contains an abrasive mixture of quartz sand (particle size 0-30mm) in water, resulting in a flow rate of 0.36m/s.
Corrosion-abrasion damage arises where corrosive chemicals carried by the water expose the inverts of storm drain pipelines.
Hostile environments result in the development of corrosion products in materials such as unprotected concrete and steel. The corroded surface is stripped, revealing a new surface which eventually develops new corrosion products.
In concrete pipes, damage may be so significant that loss of wall thickness exposes steel reinforcement rods. This is considered to be a failure of the pipe.