relative spectral irradiance in outdoor UVR spectrum [1]

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1 UV STABILITY OF ARMA-CHEK MASTIC Armacell provides innovative thermal and acoustic insulation solutions that create significant value to end users. The performance of all our products, system components and combinations, including application procedures are regularly reviewed and evaluated on an on-going basis in order to ensure long term reliability. Oil and gas activities present a number of challenges for insulation systems and coverings. One specific challenge, especially when dealing with installations located close to the equator, is the impact of ultraviolet radiation (UVR). The performance of Arma-Chek R covering with respect to UV is reasonably well known and documented. A summary for Arma-Chek R is provided towards the end of this document in the section UV resistance of Arma-Chek R covering. For Arma-Chek Mastic, which acts as a sealant for Arma-Chek R covering, the UV performance has been less widely communicated and this document therefore serves to present the key proof-points which support the technical qualification of this product for high UV environments. ISO Accelerated UV testing Effects of UVR on materials are generally considered to be the most significant towards the smaller wavelengths of natural light (< 400nm). These effects are less important in the visible spectrum (> 400nm) ISO 4892 is an industry accepted standard for testing the performance of plastic materials under accelerated UV exposure and weathering conditions. The test procedure allows for either Xenon-arc (ISO ) or fluorescent lamp (ISO ) methods to be used as the UV source. The relative spectral irradiance of both ISO & methods compared with the maximum global irradiance 1 is shown in Table 1. below: spectral band [1] Global Irradiance [1] percentage of total radiation [1] relative spectral irradiance in outdoor UVR spectrum [1] relative spectral irradiance in fluorescent lamp (type 1A) UVR spectrum [2] relative spectral irradiance in Xenon arc UVR spectrum [3] nm W/m 2 % ( nm) % ( nm) % ( nm) % ( nm) Sub Tot ( ) Sub Tot ( ) [1] CIE publication Nr. 85:1989 [2] ISO A UVA-340 (type 1A) lamp [3] ISO A daylight filters Table 1. Relative irradiance values 2 for ISO 4892 part 2 and part 3. 1 The maximum global irradiation of a horizontally mounted sample at noon at the equator at equinox as defined in CIE publication Nr 85: The ranges provided in the table are related to the allowable tolerances in test Copyright: Armacell Engineered Systems Page 1 of 7

2 In all cases of testing Arma-Chek Mastic, the total irradiance within the UVR spectrum ( nm) satisfies 60W/m 2 both for the (Xenon-arc) and for the (fluorescent lamp) methods. In order to achieve the accelerated conditions for ISO (Xenon-arc), samples are exposed to continuous, 2 hour cycles consisting of 102 minutes of UV exposure at +60 C 3 and 65% RH, followed by 18 minutes of water spray at +40 C. In order to achieve the accelerated conditions for ISO (fluorescent lamp), samples are exposed to continuous, 12 hour cycles consisting of an aging cycle of 4 hours at +50 C and 100% relative humidity (RH), followed by 8 hours at +60 C and full UV exposure, with no water spray. Prediction of Real-Life Performance Considering the accelerated testing under laboratory conditions, it is possible to make an estimate of real-life performance when the specific exposure conditions for a given location are provided. By way of example, the daily weather records, including UVR levels, are provided for Northern Queensland in Australia. (See Table 2. below) Table 2. Daily weather record (yearly overview for 2014) for Northern Queensland, Australia (source: Allunga Exposure Laboratories). As shown in the Table 2, the total global radiation (UVR) is 387 MJ/m 2 and the total number of sunshine hours is The average irradiance (UVR) during the day is therefore calculated as follows: i.e. IIIIIIIIIIIIIIIIIIII (iiii WW/mm 2 ) = AAAAAAAAAAAA GGGGGGGGGGGG RRRRRRRRRRRRRRRRRR (iiii JJ/mm2 ) SSSSnnsshiiiiii hoooooooo (iiii ssssssssssssss) IIIIIIIIIIIIIIIIIIII (iiii WW/mm 2 ) = = 3333 WW/mm Black panel temperature Copyright: Armacell Engineered Systems Page 2 of 7

3 It can be seen therefore, that the average daytime irradiance of 33 W/m² in the UVR spectrum is approximately a half of the irradiance level used in the ISO 4892 testing 4. Equivalent Exposure Periods Accelerated testing is achieved by combining both UV irradiation and thermal exposure, the latter of which is achieved by maintaining elevated chamber temperatures. From the details provided above, it can be shown that a 1000 hour continuous UVR exposure of 60 W/m 2 in a ISO 4892 test is equivalent to approximately 1,800 hours in Northern Australia at 33 W/m 2. (i.e. 1,000 hours x 60 W/m 2 = 216 MJ/m MJ/m 2 33 W/m 2 = 1,800 hours). It is assumed that the peak irradiance on a horizontal surface at noon time is approximately 55 W/m 2 which is close to the continuous exposure level created by the ISO 4892 testing. The 1,800 hours is equal to just over a half of the total sunshine hours (3,275 hours) recorded in North Queensland during The 1000 hour test performed in accordance with ISO may therefore be considered equivalent to a little over half a year UVR exposure in that location. Similarly, for a 5000 hour test performed in accordance with ISO , this may be considered equivalent to approximately 2.5 years UVR exposure in that part of Northern Australia. Thermal acceleration Assuming an Arrhenius-type thermal acceleration (i.e. doubling of reaction rate with each 10K increase of temperature), with a chamber black panel temperature of +60 C being equivalent to the noon surface temperature on a grey surface (e.g. Arma-Chek R) in Northern Australia, a thermal acceleration factor of approx. 2 is achieved in ISO chamber testing 5. Fig 1. below shows an estimated surface temperature profile. The average surface temperature during the daytime is approximately +45 C. T [ C] Extrapolated daytime surface temperature profile for Northern Australia 0 00:00 02:24 04:48 07:12 09:36 12:00 14:24 16:48 19:12 t [hh:mm] Fig.1. Extrapolated daytime surface temperature profile for Northern Australia. 4 This calculation method has been independently verified by Allunga laboratories. 5 Details on the calculation method can be obtained by contacting our Technical Customer Service. Copyright: Armacell Engineered Systems Page 3 of 7

4 This results in a doubling of the equivalent exposure period such that in the ISO test a 1000 hour test may be considered to represent 1 year in Northern Australia. Similarly, a 5000 hour test may be considered to represent 5 years in Northern Australia. It should be noted that the scenario for Northern Australia, as described above, represents a very high UV environment. The equivalent exposure periods for other regions may vary considerably from the above such that the ISO tests represent much longer periods at those locations. UV Resistance Testing UV resistance test of Arma-Chek Mastic has been performed according to both ISO and methods and subjected to both visual and mechanical performance assessment following exposure. Fig. 2a and 2b show representative results for the mechanical properties of Arma-Chek Mastic assessed in accordance with ISO 37 after 1, 2, 4 and 6 months QUV exposure according to ISO (fluorescent lamp). The change in performance during the 6 months exposure (equivalent to 3000 hours 6 of continuous exposure) is considered to be small and will have no impact the performance of the mastic in-situ. (a) (b) Fig.2. Typical mechanical properties for Arma-Chek Mastic Samples following 0,1,2,4 and 6 months QUV exposure acc. ISO (fluorescent lamp) testing. (Note: % MPa refers to the relative mechanical value compared to the initial, un-exposed sample). Visual assessment on the performance of Arma-Chek Mastic has been performed after undergoing 5000 hours of exposure in accordance with ISO (Xenon-arc). Fig. 3 and 4. below shows the appearance of the Arma-Chek Mastic following exposure for 3000 and 5000 hours x 8 hour cycles per 24 hrs multiplied by 183 days 3000 hours 7 Actual images shown are for 3000 hours and 4800 hours, respectively Copyright: Armacell Engineered Systems Page 4 of 7

5 (a) 3000 hrs (b) 5000 hrs Fig.3. Visual appearance of Arma-Chek Mastic bead following 3000 (Fig 3.a) and 5000 (Fig 3.b) hours exposure acc. ISO (Xenon-arc) testing. The observations demonstrate that while superficial cracking may appear on the surface of the bead, this is in line with the known aging process and is consistent with materials based on saline modified polymers (SMP). 0 hrs 1000 hrs 3000 hrs 5000 hrs Fig.4. Magnified images showing superficial surface changes following 5000 hours 8 exposure acc. ISO (Xenon-arc) testing. The superficiality of the cracking can be better assessed by way of viewing the cross-section of the exposed mastic bead. Fig 5. below shows a cross section of the bead following 5000 hours exposure. It can be seen that the crack penetration after 5000 hours is less than 150 µm on the tested samples (i.e µm per 1000 hours). Assuming the acceleration factors described earlier for Northern Australia, a real-time ageing of approximately 3 years has been simulated after 3000 hrs. Given the observed crack propagation rate, the exposure to UV alone is not expected to reduce the lifetime of the mastic below 10 years. 8 Actual images shown are for 1200 hours, 3000 hours and 4800 hours, respectively Copyright: Armacell Engineered Systems Page 5 of 7

6 Superficial surface cracking Arma-Chek Mastic Arma-Chek R covering Fig.4. Magnified cross-section of Arma-Chek Mastic bead following 5000 hours exposure acc. ISO (Xenon-arc) testing UV resistance of Arma-Chek R Covering The UV performance of Arma-Chek R covering is well documented and will not be discussed in great detail within this technical bulletin. In summary the UV performance has been measured in accordance with ISO and assessed for real-life performance behaviour under accelerated real-life exposure conditions. A short explanation on the behaviour of Arma-Chek R covering is provided below: When tested to ISO (Xenon-arc), the material is shown to maintain its physical properties but with slight discolouration in the appearance of the material (Ref: certificate 6232_Arma-Chek R_UV Testing_EN ISO _Aucoteam Berlin_ ). Samples of Arma-Chek R were also subject to long-term accelerated UV resistance tests at the Allunga Exposure Laboratory in Townsville, North Queensland, Australia using the Altrac configuration. Altrac units allow concentrated exposure to natural solar radiation and reaches long-term acceleration levels of within % compared to normal exposure. These radiation levels are measured with a specially designed pyranometer sensor measures radiation in the target area. In the tests performed, samples of Arma-Chek R in both 1mm and 2mm thickness were irradiated in the Altrac configuration for 12 months. During this time, changes in colour and surface appearance were continuously monitored and logged. The samples evaluated in the Altrac configuration showed medium colour mottling and no yellowing or brittling after 12 months of exposition. Very thin cracking, visible only under magnification, was noted to appear between 9 12 months of exposition. The total amount of radiation received by the samples in the Altrac configuration was 36,815 MJ/m 2. In reference to a standard Xenon weatherometer with an output of 60 W/m 2 or MJ/m 2 per hour, the Copyright: Armacell Engineered Systems Page 6 of 7

7 total radiation received by the samples in the Altrac positioning would equal 166,000 hours of irradiation in the given reference weatherometer. Compared to an 8,000 hr Xenon test, the lifetime of the material is expected to exceed 10 years in realtime application. Long-term Proven Performance Arma-Chek covering systems, consisting of Arma-Chek R and Arma-Chek Mastic materials, have been supplied into the oil and gas segment for almost 15 years and Armacell has an extensive list of highly successful projects located all over the world and in challenging climatic and high UV conditions. Some of the long serving projects include: - Sonatrach Skikda LNG liquefaction facility in Algeria - Saudi Kayan SK Olefins Plant, Al-Jubail, Saudi Arabia - AUM Ammonia plant, Trinidad - EBIC Ammonia Plant, Egypt The accelerated UV performance testing coupled with the long service history with the Arma-Chek covering system demonstrates consistency with our declared technical statement that the UV stability of Arma-Chek Mastic is rated as excellent. Copyright: Armacell Engineered Systems Page 7 of 7