Tests as per Bureau of Indian Standards Measurements Test
This test method covers the determination of diameter, wall thickness, and length dimensions of thermoplastic pipe. Included are procedures for measurement of the inside diameter of pipe intended to be joined by internal fittings, measurement of the average outside diameter for roundable pipe where out-of-roundness is not of primary concern, out-of-roundness measurement and measurement of the average outside diameter of non-roundable pipe, and for determining length and straightness.
This test determines the quality of raw materials like PVC Resin and also the proportions of additives used. The density of pipes ranges from 1.4 – 1.46.
Density test apparatus are based on well defined mechanism that helps in providing simultaneously rotating & tapping motion to cylinders for packing sample under test, evenly as well as uniformly.
Short Term and Long Term Hydrostatic Pressure Test
A hydro static test is a way in which leaks can be found in pressure vessels such as pipelines and plumbing. The test involves placing water, which is often dyed for visibility, in the pipe or vessel at the required pressure to ensure that it will not leak or be damaged. It is the most common method employed for testing pipes and vessels. Using this test helps maintain safety standards and durability of a vessel over time. Newly manufactured pieces are initially qualified using the hydrostatic test. They are then continually re-qualified at regular intervals using the proof pressure test which is also called the modified hydrostatic test. Hydrotesting of pipe and pipelines is done to expose defective materials that have missed prior detection, ensure that any remaining defects are insignificant enough to allow operation at design pressures, expose possible leaks and serve as a final validation of the integrity of the constructed system.
Effect on Water
Pipes shall not have any detrimental effect on the composition of water flowing through them. This test is carried out to ensure that raw materials used to manufacture the pipe do not contaminate water with toxic substances. Purity of water is tested. This test method covers measurement of the loss of compressive strength resulting from the action of water on compacted bituminous mixtures containing asphalt cement. A numerical index of reduced compressive strength is obtained by comparing the compressive strength of freshly molded and cured specimens with the compressive strength of duplicate specimens that have been immersed in water under prescribed conditions.
Residual stresses inherent in the extrusion of plastic pipe products may have long term adverse effects on product performance. In particular, environment stress cracking is accelerated in pipes with high frozen in internal stresses. Longitudinal Reversion Test is a method of determining the level of internal stresses in pipes.
A pipe of specified length is placed in an air oven at a specified temperature for a specified time. A marked length of this portion of pipe is measure before and after heating. The reversion is calculated as a percentage of the change in length in relation to the initial length. Test may only be performed on pipes 24 hours after production.
This test determines the optical characteristics of plastics like transmission of light through the specimen. Star UPVC Pipes resist sunlight passing through the pipe walls do not pass more than 0.2% of the light incident on them.
Opacity represents a substrate’s light blocking ability. It is primarily used as a property of paper and predicts the relative visibility on one side of the paper of the images that exist on the other side. There are two common types of opacity measurements, the one called “89% reflectance backing,” also called “contrast ratio.” This value is equal to 100 times the ratio of the diffuse reluctance of a film sample backed by a black body (<.5% reluctance) to the diffuse reluctance of the same sample backed by a white body (89% reflectance). The units are percent, and a perfectly opaque material will have an opacity value of 100%.
Resistance to External blows
When tested by this method, pipes shall have a true impact rate of not more than 10%. After keeping the test specimen in deep freezing chamber for about an hour specific weight is dropped from specific height to ensure that the specimen withstands the desired impact.
“Round the Clock Method” Lengths of pipe from a batch or production run are subjected to blows from a known mass which falls from a specified height. “Staircase Method” Lengths of pipe are subjected to blows from a known mass and shape but is dropped from differing heights depending on the results of each blow.
Vicat Softening Temperature
This test method is useful in the areas of quality control, development, and characterization of plastic materials.This test method covers determination of the temperature at which a specified needle penetration occurs when specimens are subjected to specified controlled test conditions.
A test specimen is placed in the testing apparatus so that the penetrating needle rests on its surface at least 1 mm from the edge. A load of 10N or 50N is applied to the specimen. The specimen is then lowered into an oil bath at 23 degrees C. The bath is raised at a rate of 50° or 120° C per hour until the needle penetrates 1 mm. Due to the potential safety and environmental hazards associated with mercury-filled thermometers, the use of alternative temperature measuring devices (such as thermoplastic and RTDs) are use