UL 1002:2006 pdf download – Electrically Operated Valves For Use In Hazardous (Classified) Locations
UL 1002:2006 pdf download – Electrically Operated Valves For Use In Hazardous (Classified) Locations.
15 HydrostatIc Pressure Test
15.1 Each electncal enclosure for use in Class I locations shall withstand for 1 minute without rupture or permanent distortion an internal hydrostatic test pressure of not less than four times the maximum internal explosion pressure developed during the explosion tests.
Exception: The hydrostatic plessure test may be omitted if calculations indicate a factor of safety of five for the encioslrrg parts and bolts based on the maximum explosion pressure and the tensile strength of the materials.
15.2 The hydrostatic pressure is to be applied at a rate of approximately 100 psig (690 kPa) per minute until the required internal pressure is reached. A gasket or other acceptable means may be employed if necessary to prevent leakage of water during application of pressure.
16 Dust-Penetration Test
16.1 An electrical enclosure for use in Class II locations shall be exposed to circulating dust-air atmospheres to determine that the enclosure will prevent the entrance of dust. Dust shall not enter the enclosure as determined by visual examination following the test described in 16.2.
16.2 The enclosure Is to be installed In a test chamber to permit free circulation of dust-air mixtures around the device. The lest chamber is to be provided with a cover and with dust-air-inlet and -outlet connections. The enclosure is to be exposed to the dust-air atmosphere that is to be produced by auxiliary apparatus and introduced into the test chamber. The test is to be continued for at least six heating and cooling cycles covering at least 30 hours while the enclosure is continuously exposed to the circulating dust-air atmosphere.
16.3 The test is to be conducted at an ambient temperature of 10 — 40’C (50 — 1O4CF) and a relative humidity of 40 – 60 percent.
16.4 Grain dust, consisting of wheat dust or corn dust, or both, that has passed through a U.S.A. Standard 150 micron (100 mesh) wire cloth is to be used for the dust-air atmosphere if the valve is for use in Class II, Group F, Group G, or Group F and G locations.
16.5 Magnesium dust, all of which has passed through U.S.A. Standard 250 micron (60 mesh) wire cloth.
66 percent of which has passed through a 150 micron (100 mesh) wire cloth, and 22 percent of which has passed through a 75 micron (200 mesh) wire cloth, is to be used for the dust-air atmosphere if the valve is for use in Class II, Group E, Groups E and F, or Groups E, F, and G locations.
16.6 The wire cloth is to conform to the dimensional requirements of Standard Specification for Wire-Cloth Sieves for Testing Purposes. ASTM El 1-87.
17 Raintightness Test
17.1 An electrical enclosure for a valve intended for Outdoor use shall be constructed so that it will exclude a water spray.
17.2 Unless an enclosure is constructed so that it will exclude a water spray, the device is to be mounted with raceway connections as in actual servtce. The device is then to be exposed for 1 hour to a water spray as specified in 17.3,
17.3 The water spray apparatus is to consist of three spray heads mounted in a water.supply pipe rack as illustrated In Figure 17.1. The spray heads are to be constructed as illustrated in Figure 17.2. The water pressure for all tests is to be maintained at 5 psi (34.5 kPa) at each spray head, The distance between the center nozzle and the unit is to be approximately 5 feet (iS m). The electrical enclosure is to be brought into the focal area of the three spray heads in such a position and under such conditions that are most likely to result in entrance of water into the enclosure, The spray is to be directed at an angle of 45 degrees to the vertical toward the joints and shaft openings of the enclosure. It may be necessary to operate the unit under various modes of operation or de-energize the unit if more adverse conditions could result.