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AtlasPlus - Laboratory Testing
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The stringent specifications with which Interplast harmonizes in the production of ATLAS-PLUS pipes and fittings, are certified in its state-of-the-art laboratories by experienced scientific personnel, with tests specified by European standard EN 1451 and German standards DIN 19560-10 & DIN 4102-1.
The order to release a lot is issued only after successful results are reached through the following testing procedures:
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It is a regular test carried at every time raw materials are delivered. It examines the consistency of the material's specifications according to the supplier, and at the same time a check is carried out whether its rhoelogy agrees with the specifications of the standards, which is directly related to the suitable temperature extrusion profile, and therefore the correct treatment and the correct homogenization of the material.
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For measurements of external diameter, wall thickness and oval of pipes and fittings, as well as elastic rings, by calibrated instruments. All Interplast measurement instruments are of German and Japanese manufacture and stand out for the exceptional accuracy of their measurements.
Essentially these are checks that examine and certify ongoing measurements carried out throughout production.
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The small divergence of the flow index of the material of the pipe and the fittings from the flow index of the raw material used for their manufacture, translates into the perfect processing of the material during production. This requires the observance of the ideal parameters at extrusion, such as for example the temperature profile, the pressure, the cooling, the screw turns, the production speed, etc. According to the specifications, divergence cannot exceed 20%. ATLAS-PLUS pipes and fittings have a flow index divergence up to 5%, which shows the excellent quality of their manufacture.
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It is related to one of the most important quality checks and it is carried out according to the specifications of international standard ISO 18553. The full compliance of the material of ATLAS-PLUS pipes with the specifications of the standard, is translated into certainty that the pipe will withstand any adverse conditions and maximum reliability during the practically unlimited lifespan due to lack of imperfections in the structure of the pipes and fittings’ material.
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Specimens from each production lot remain in a lab stove at 150oC for 60min (1h) and after they are cooled down to 23oC the % of their adjusted contraction is measured (original measurement – final measurement) / (original measurement) x 100).
According to the specifications, the results of the measurements cannot exceed 2.0%. The results of ATLAS-PLUS pipes are in the order of 0.5%, which means that they are 75% lower than the standard’s specification. This translates into certainty that the raw materials used are of the highest quality and that they are perfectly processed, and also that thermal linear expansions of the pipes during their operation are particularly low with internal high temperature drainage.
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The advanced impact testing device that uses a dropping weight (according to standard EN 1451), consists of the dropping tower and a variety of calibrated spheres of various weights. The testing procedure and the impact speed are specified in standard EN 744.
The pipes must respond without breaking or cracking in the appropriate testing conditions (at 23oC according to the standard) after the impact caused by the falling weight (sphere). The dropping height and the weight of the sphere during the test are proportionate to the pipe’s external diameter.
Atlas-Plus pipes greatly exceed the requirements of the standard, with mechanical strengths during impact of heavier spheres from greater heights compared to the standard’s specifications, but mainly at temperatures much lower than 23oC, which are in the order of 5 degrees Celsius below zero (-5oC)>
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Even though negligible pressures build up in the interior of building sewage pipes class B from the weight of drainage, the situation is different for pipes class BD, which connect building sewage with the central city sewage network and are called upon to withstand pressures created from the weight of the building’s total drainage.
In order to ensure their resistance to these pressures, tests are carried out by the corresponding device according to the specifications of standard EN 1451.
Pipe specimens are tested in the hydrostatic pressure appliance for 140h at 80oC (σ=6,0 ΜΡa) and for 1000h at 95oC (σ=3,5 MΡa) “σ” is the peripheral tension that builds up on the pipe’s wall and tends to tear it with tensile forces, a result of the internal hydrostatic pressure created from the corresponding testing appliance. Pressure P (in bar) applied in the tests, is calculated taking into account the pipe’s diameter (D in mm), it wall thickness (e in mm) and the σ value (Ρ=20ΧσXe/D-e).
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Tensile strength tests are performed in a tensile appliance and the elasticity and elongation factors of the material are determined, in pipe and fitting specimens appropriately prepared by a special instrument. All results are recorded on a computer, where the measurements are then analyzed with the help of special diagrams.
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