Enclosures equipment

Initially, DADC polymers were used in military aircraft for windows of fuel and deicer-fluid gauges and in glass-fiber laminates for wing reinforcements of B-17 bombers. Usage in impact-resistant, lightweight eyewear lenses has grown rapidly and is now the principal appHcation. Other uses include safety shields, filters for photographic and electronic equipment, transparent enclosures, equipment for office, laboratory, and hospital use, and for detection of nuclear radiation. 

Polymerizations were carried out in Pyrex test tubes in a stainless steel enclosure equipped with a cooling bath, inlets for gaseous reagents and a water analyzer. Nitrogen gas was flushed continuously to maintain a moisture level below 30 ppm. 

In principle the usual type of circulating air laboratory oven can be used for conditioning test pieces when temperature only is controlled. However, for temperatures near to ambient, enclosures equipped with cooling coils would be essential. If a cabinet has to be used it would probably be more... 

High voltage equipment (e.g. for use in electrophoresis, or in the generation of ozone) requires special precautions. Ideally, such apparatus should be isolated within an enclosure equipped with an interlocking device so that access is possible only when the current is switched off. 

A Na-S battery comprises several elements coimected in series and/or in parallel. These elements are placed in a thermal enclosure equipped with electrical resistors to keep the reaction temperature at around 300°C. 

When lightning strikes the nearest tower to a substation, a diode for a surge protection of a relay of a CB enclosure equipment, 52X1 in Figure 6.9a, is broken, and an auxiliary relay contact is melted. Also, it is found that an auxiliary relay coil of a telecontrol equipment for indication, 79SX1 in Figure 6.9a, is broken. 

Experiments and even production operations can be conducted at any frequency providing the radiated and conducted signals meet the apphcable tfi limits for ISM equipment. Tests to certify this stipulation must be carried out before inception of operations. This implies weU-shielded enclosures at high power levels which is expensive but justified in certain apphcations. 

One feature of reprocessing plants which poses potential risks of a different nature from those ia a power plant is the need to handle highly radioactive and fissionable material ia Hquid form. This is necessary to carry out the chemical separations process. The Hquid materials and the equipment with which it comes ia contact need to be surrounded by 1.5—1.8-m thick high density concrete shielding and enclosures to protect the workers both from direct radiation exposure and from inhalation of airborne radioisotopes. Rigid controls must also be provided to assure that an iaadvertent criticahty does not occur. 

The other space-saving approach is to use the Kobe (Kobe Steel) type of channel enclosure, which does not have all the external head bolts of typical TEMA Type B or Type C head enclosures. These exchangers require special tools to remove the tube bundles and trained maintenance personnel to do the work. These exchangers should never be located in stmctures because of the need to be able to access the channel from grade as it is difficult to remove the channel cover plate by using special equipment. 

A. B. Shuck and R. M. Mayfield, The Process Equipment and Protective Enclosures Designedfor the Fuel Fabrication Facility, Facility No. 350, ANL-5499, Argonne National Laboratory, Argonne, lU., 1956. 

The dust-ignition-proof protection concept excludes dust from entering the device enclosure and will not permit arcs, sparks, or heat generated by the device to cause ignition of external suspensions or accumulations of the dust. Enclosure requirements can be found in ANSI/UL 1203-1994, Explosion-Proof and Dust-Ignition-Proof Electrical Equipment for Use in Hazardous Locations. ... 

Environmental Enclosures Enclosures for valve accessories are sometimes required to provide protection from specific environmental conditions. The National Electrical Manufacturers Association (NEMA) provides descriptions and test methods for equipment used in specific environmental conditions in NEMA 250. Protection against rain, windblown dust, hose-directed water, and external ice formation are examples of environmental conditions that are covered by NEMA standards. 

NFPA 496 Standard for Purged and Pressurized Enclosures for Electrical Equipment,... 

The permissible amount of talcum powder penetrating the enclosure should not affect operation of the equipment. The test is similar as for number 5 but now no deposit of dust should be observed at the end of the test. 

After the test the amount of w-ater w hich might have entered the interior of the enclosure should not interfere with satisfactory operation of the equipment. No w-aier should accumulate near the cable gland plate or enter the cables. 

The test equipment is the same as described for degree of protection I. But the enclosure under lest is tilted up to an angle of 15° in respect of its normal operating position successively, in iw o planes at right angles (to cover all four sides). The total duration of the test will be 10 minutes (2.5 minutes each side). The lesl results should be the same as for degree of protection I. 

Enclosure for electrical equipment up to lOOOV. Test criteria and design tests Industrial controls and systems. Enclosures... 

The enclosure, however, should be insulated at all such locations, where the IPB terminates with another equipment, such as at the generator, GT, UATs, VTs, and the NGT to avoid longitudinal currents through such equipment. These equipments are grounded separately. 

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