PE Thermal Properties

Polyethylene pipes can be used at temperatures ranging from -50 °C to +60 °C.

At higher temperatures, the tensile strength and stiffness of the material are reduced. Therefore, please consult the pressure-temperature diagram. For temperatures below 0 °C it must be ensured, as for every other material that the medium does not freeze, consequently damaging the piping system.

Like all thermoplastics, PE shows a higher thermal expansion than metal. GF PE has a coefficient of linear thermal expansion of 0.15 to 0.20 mm/m K, which is 1.5 times greater than that of e. g. PVC. As long as this is taken into account during the planning of the installation, there should be no problems in this regard.

The thermal conductivity is 0.38 W/m K. Because of the resulting insulation properties, a PE piping system is notably more economical in comparison to a system made of a metal like copper.

Acceptable storage of plastic pipes

The pipe storage surface must be level and free of stones. Pipes must be layered and stacked in a way that avoids the risk of damage or permanent deformation.

Larger-diameter, thin-walled pipes must be fitted with stiffening rings. Avoid single-point or narrow longitudinal supports.

The list below gives recommended maximum stacking heights for non-palette pipe storage. Provided pipes are stacked on palettes and protected against sideways movement, the nominal stacking heights specified in the list may be increased by 50%.

Pipe storage areas should be as well-protected as possible.

Absorption of oil, solvents and other chemicals must be avoided at all costs during storage. Stored pipes must not be exposed to the elements more than absolutely necessary, i.e. they should be kept in a covered warehouse. If stored outdoors (e.g. on a construction site), they should be covered with sheeting for protection against the weather (e.g. UV radiation).

It should also be noted that one-sided warming by sunshine could cause deformations.

Pipes and parts should be used in the order of manufacture/ delivery, to ensure proper warehouse turnover of the plastic material.

Material Permissible stacking heights

ABS                             1.0m

PE                                1.0m

PP                                1.5m

PVC-U                          1.5m

PVC-C                          1.5m

PVDF                           1.5m

Processing of Plastics

Plastics are processed differently depending on the material and application. Some common methods are:

  • Extrusion
  • Compression moulding
  • Injection moulding
  • Foaming

Extrusion

In this process thermoplastic material is melted and is continuously forced through a tool via a worm screw. The extruded bar is then calibrated, cools down and is withdrawn via a take-off unit.

Compression moulding

Thermosetting material is poured into the open compression mould in powder form. Under the impact of the mould pressure and heat, it then chemically reacts and solidifies to the desired finished part.

Injection moulding

Thermoplastic material in granular or powder form is gradually melted in the cylinder and the mass is injected by means of the worm screw into a mould under high pressure. The plastic then solidifies and is ejected from the mould as a finished part.

Steam Foaming

Granular plastic containing a blowing agent is injected into the mould, expanded by means of hot steam, cooled with water and ejected from the foam mould as an extremely light weight part. Water absorption is impossible as all pores are closed.

 

 

Efficiency in Cooling

The cold chain and environmental climate control are integral parts of modern day life. We simply expect fresh food twelve months of the year and of course the fresher the better. Climate control whether in hospitals or for medicines are determining factors in the quality of our lives. The generation of cold for a whole range of applications is part of day-to-day life.

Refrigeration plants are major users of energy and play a key role in environmental protection. In a supermarket, for example, 70 % of the daily energy costs are attributed to the cooling and refrigeration plant. Cold stores and food production facilities with cooling performance energy requirements of many megawatts are common. Any technology improvements which improve the efficiency of refrigeration and cooling plants have real ecological as well as economic benefits.

Reflections on pipeline work

Planning and installation of piping systems is a true engineering task, necessitating the organisation of a multitude of requirements and goals. For piping installations, simple, critical and aggressive media in each case require suitable materials. The idea is to especially cover the requirements of functionality, operating safety, optimal service life, environmental conditions and adequate profitability. Included in this are overall ecological, technical and economic assessments. High-performance plastics for piping installations are proven and implementable where special endurance problems in connection with the media need solving.

Environmental protection is an important responsibility affecting us all. Each one of us, businesses and industrial concerns alike have to meet this great challenge.

Plastics, the basics

Plastics are materials which are created by chemical conversion of natural products or in a synthetic manner from organic compounds. The main components are the elements carbon (C) and hydrogen (H). The bases of most plastics are carbon-hydrogen compounds, from which the single components of plastics, the so-called monomers, are produced.

1) Synthesis: production of a chemical compound from different elements or simple molecules. Synthesis is the opposite of analysis.

2) Organic media are pure non-metals of natural occurrence, e. g. petroleum, coal, wood, natural gas.

Inorganic media are compounds of metal and non-metals, e .g. minerals, ores etc.

3) Monomers are the basic molecules, i. e. the smallest components of which plastics are built. 

Raw materials for the manufacture of plastics are natural compounds, such as cellulose, coal, petroleum and natural gas. In a refinery, petroleum is separated into several components by means of distillation.

Grouped into vaporisation ranges, gas, benzene, petroleum, gaseous oil, and as residue bitumen are obtained during distillation.

All components consist of hydrocarbons which only differ in size and form of the molecules. The most important component for plastics production is crude benzene.

In a heat cracking process this crude benzene is broken down into ethylene, propylene, butylene and other hydrocarbons and is then modified.

Distribution of Chemicals – Best handling

In the chemical distribution business, the highest product quality and a maximum of process reliability is an absolute must because chemical media are transported in diverse concentrations and dosages. Transporting chemicals from their storage place to the actual process application must be planned and carried out reliably and safely. This means the materials used in the piping system must be one hundred percent compatible with the properties of the chemicals.

Whether a manufacturing facility receives deliveries of large liquid supplies or distributes liquids to customers, the fluid is transported, in bulk, via large tanker trucks, railroad cars, drums, etc. These liquids are usually tightly controlled and filling or emptying the bulk container must be closely monitored using flow sensors and instruments.

Choosing the most suitable piping system, including automation technology, allows you not only to increase productivity and reduce maintenance costs, but also to realise a significant improvement in product quality for your customers.

Drinking Water

The shortage of drinking water and subsequently the valuable nature of the resource, gives high significance to an efficient purification process. Several sources for the production of drinking water – varying from groundwater and sea water through to surface or brackish water – have been exploited over the years, demanding diverse treatment efforts. In this context, legal and normative standards, together with specific requirements of the distribution grids, give direction to the design of the processes.

Ensuring drinking water supply worldwide is one of the key challenges today and therefore one of the most important and fastest growing industry sectors. Systems for water intake, production, purification and distribution need to adapt to the diverse regional conditions. Despite the differences, a constant high water quality is required throughout the whole process, which places high demands on the system solutions.

Understanding ABS

Acrylonitrile-Butadiene-Styrene (ABS) is a versatile standard polymer. In addition to its application in piping systems, ABS is mainly common in automotive applications and in high-quality household devices. The wide area of application relates to the versatile characteristic profile of ABS. It can be adapted to the application by varying the composition of its three components: acrylonitrile, styrene and polybutadiene. While acrylonitrile provides strength to the material and gives ABS an improved chemical resistance relative to polystyrene, the styrenic component provides both strength and a quality surface finish. The chemically bound polybutadiene rubber particles, on the other hand, give the material its toughness and impact strength, even at very low temperatures.

About Polyamide (Nylon) Pipe Systems

Polyamide (Nylon) gas pipe system is a revolutionary plastic pipe system developed for the gas industry, used for both direct burial and rehabilitation of existing cast iron and steel gas mains.

The excellent chemical resistance properties of Polyamide 11 (PA11) and Polyamide 12 (PA12), permits the conveyance of natural, manufactured or LP gases containing small amounts of aromatic and other condensable hydrocarbon impurities.

High tensile strength of polyamides enables the production of thin walled pipes with comparable strength, compared with much heavier walled polyethylene pipes.

Polyamide can withstand considerable stresses at peak temperatures in the region of 80°C (dry heat).

Polyamide pipes have excellent chemical resistance to heavy hydrocarbons at ambient temperatures.

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