Prefabricated Units

Figure 11-69 describes a typical central system. Either water or direct-expansion refrigerant coils or air washers may be used for cooling. Steam or hot-water coils are available for heating. Humidification may be provided by target-type water nozzles, pan humidifiers, air washers, or sprayed coils. Air cleaning is usually provided by cleanable or throwaway filters. Central-station air-conditioning units in capacities up to about 50,000 cu ft/min are available in prefabricated units. 

Prefabricated units, other than regularly manufactured buttwelding fittings, that employ plate and longitudinal seams, as contrasted with pipe that has been produced and tested under one of the specifications listed in this Part, shall be designed, constructed, and tested under requirements of the ASME BPV Code Section VIII, Division 1. These requirements are not intended to apply to such partial assemblies as split rings or collars, or to other field-welded details. 

The CO P catalytic oxidation system is a complete prefabricated unit used to treat wastewater contaminated with volatile organic compounds (VOCs) and high biological oxygen demand and chemical oxygen demand. The system uses ozone, ultraviolet light, and hydrogen peroxide to create hydroxyl radicals used in oxidation. 

Slabbing. (1) The fixing of ceramic tiles to fireplace surrounds, etc., to produce a prefabricated unit. 

A mobile access tower Figure 4.6.6) is a tower constructed of prefabricated aluminium units that click together to form a rigid frame. The use of prefabricated units allows a range of tower sizes to be assembled. Each working platform level is provided with handrail, intermediate rail and toe board on all four sides and is capable of supporting an evenly distributed load of 275 kg. Towers can be assembled up to a maximum height of... 

A prefabricated unit (PFU) is a collection of atoms and bonds that are deposited together as a unit (Figure 12). Once constructed, the atoms of a PFU will not be moved relative to each other. They may be translated and rotated, but the absolute distance between every constituent pair of atoms (in 2-D, as always) is preserved. One would use PFUs in three situations ... 

In addition to determining atom coordinates, prefabrication of rings also requires the CFS at each ring atom. As with the coordinates, which are called local because they are intermediate and relative (see section above on Prefabricated Units), these are stored as distinct local CFSs in an auxiliary array. Not until assembly are real CFSs manipulated. 

Gas flotation equipment is typically purchased as a prefabricated unit selected from a vendor s list of standard size units, rather than being custom specified and designed for each specific application. As a result the bulk of the design is performed by the vendor, and relatively little design opportimity exists for the user. 

---