UL 2420-2016 pdf download

UL 2420-2016 pdf download.Belowground Reinforced Thermosetting Resin Conduit (RTRC) and Fittings.
5.5.9 The specimens immersed for 90 days shall be in thermal equilibrium with the testing machine and the surrounding air at a temperature of 23 ±2CC (73 ±4F). The inside diameter of each specimen shall be measured and recorded, The specimens shall be tested separately between a pair of ngid, flat steel plates that are at least 150 mm (6 in) long and that are horizontal and parallel to one another. The measured inside diameter shall be perpendicular to the platens. One plate shall be moved toward the other at the rate of 12.7 ±3.2 mm/mm (0.5 ±0.125 in/mimi)
a) until the surface of the specimen pulls away from contact with either plate, that Is, until the specimen buckles; or
b) until the minor axes measured inside the flattening specimen is 60 percent of the inside diameter measured before Ihe test.
5.5.10 The crushing loads at the buckling and the 60 percent points shall be noted from the dial on the machine and recorded for each specimen. The loads at each of these points shall be averaged for the set of six specimens. The average loads at each of these points for the immersed specimens shall be divided by the average loads at each of these points for the unaged specimens. The resulting ratios shall not be less than 0.85, and no conditioned specimen shall crack or collapse before buckling or the 60 percent point is reached.
5.6 Watertightness
5.6.1 Coupled conduit and fittings shall nof leak when tested in accordance with Clause 5.6.2.
5.6.2 A 300±3mm (12.0±0.125 in) length of conduit shall be inserted into the integral coupling of another length of conduit having a total length of 300 ±3 mm (12.0 ±0.125 in), according to the manufacturer’s installation instructions.
5.6.3 In the case of an elbow or fitting. one or two 300 ±3 mm (12.0 ±0.125 in) lengths of conduit, as appropriate, shall be inserted Into the coupling according to the manufacture?s instructions. One end of the assembly shall be capped with a suitable enclosure. The assembly shall be placed in the vertical position, with the sealed end at the bottom, and filled with tap water. After a minimum of 4 h. the specimen shall be visually examined to determine any evidence of leakage.
5.7 Joint separation
5.7.1 A jolit (conduit and socket) shall not separate when tested in accordance with Clause 5.7.2.
5.7.2 Two joints in each trade size shall be assembled as intended. A gasketed joint shall be subjected to an axial pull of 444 N (100 lbf), applied to the assembly for 5 mm, and tending to pull the conduit out of the socket. A mechanical or threaded joint shall be subjected to an axial pull of 4448 N (1000 tf), applied to the assembly for I mm, and tending to pull the conduit out of the socket. An adhesively secured joint shall be subjected loan axial pull of 6670 N (1500 lbf), applied to the assembly for 1 nun, and tending to pull the conduit out of the socket.
5.8 Flattening resistance
58.1 The vertical inside diameter of conduit shall not decrease by more than the value indicated in Tables 15 and 16 when tested in accordance with Clause 5.8.2.
5.8.2 Two specimens shall be tested. Each specimen shall be 75 ±3 mm (3 ±0.125 in) long. The vertical inside diameter of each specimen shah be measured and the value recorded. The specimens shall be placed honzontally side by side between the 2 steel platens 01 a static load lest as shown in Figure 3. The specimens shall be placed such that the measured vertical inside diameter is in the vertical position. No part of the specimen shall extend beyond either platen. A test mass of 45 kg (100 Ib), including the mass of the upper platen, shall be symmetricalty applied. This assembty shall be maintained at a temperature of 110 ±1°C (230 ±2°F) for a period of 24 h. The specimens shall be allowed to cool, with the test mass removed, at 23 ±2°C (73 ±4F) for a minimum of 1 h. The vertical inside diameter shall be re-measured, recorded, and the actual decrease calculated and recorded.
5.9 Halogen content
5,9.1 The halogen content shall not exceed 0.2% by weight, using the calculation method described en Annex A.
5.10 Infrared spectroscopy
5.10.1 General
5.10.1.1 Analysis shall be done with an infrared spectrophotometer and the results shall be recorded as a plot of the transmittance (%) versus the frequency of the infrared radiation. The plot shall be recorded over the entire wavelength range of the Infrared instrument, approximately 2.0 to 20.0 pm (wave number 5000 to 500 cm). The scan shall be retained as a permanent record of the analysis.
5.10.2 Preparation
5.10.2.1 The general technique for prepaflng thermoset polymers for infrared analysis shall be to use a fine file to file a sample from the specimen. These filings may be ground in a mechanical vibrating ball mill. The sample shall be ground in short intervals to prevent heating of the sample. Liquid nitrogen may be used to cool the sample during grinding. Care shall be taken to reduce the particles to a size (approximately 2 pm) smaller than that of the shortest wavelength to be scanned, to minimize scattering effects. The ground specimen shall be thoroughly mixed with spectroscopic grade potassium bromide, and an amount of this mixture sufficient to produce a 1 mm (0.04 in) thick diameter disk shall be placed in an evacuable die. The die shall be placed under vacuum and a pressure of 69 to 103 MPa (10.000 to 15.000 lb film3) shall be applied. The pressed disk shall be removed from the die and mounted in a spectrophotometer and the infrared spectrum of the material recorded.