Supporting Plastic Pipelines

What is a loose pipe bracket? A loose pipe bracket is a bracket which allows axial movement of the pipe, to allow stress free compensation of temperature changes and compensation of any other operating condition changes. The inner diameter of the bracket should be larger than the outside diameter of the pipe to allow free movement of the pipe. The inner edges of the brackets should be free from any sharp contours which could damage the plastic. If the brackets’ inside diameter is not larger than the pipe then the bracket should not be fully tightened, thus allowing the pipe to move. Another method is to use brackets with spacers, which also avoids clamping the bracket on the pipe. Axial movement of the pipeline must not be prevented by fittings placed next to pipe brackets or by any other component affecting the diameter of the pipe. Sliding brackets and hanging brackets permit the pipe to move in different directions. Attaching a sliding block to the base of the pipe bracket permits free movement of and hanging brackets are needed in situations where the pipeline changes direction and free movement of the pipe must be...

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...

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                          ...

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...