evaporator unit in chassis or in air-duct system, using hand tools. This mechanic also cuts and bends tubing to
correct length and shape, using cutting and bending equipment and tools, cuts and threads pipe, using machine-
threading or hand-threading equipment, joins tubing or pipes to various refrigerating units by means of sleeves,
couplings or unions, and solders joints, using torch, forming complete circuit for refrigerant, installs expansion and
discharge valves in circuit.
This worker connects motors, compressors, temperature controls, humidity controls, and circulating ventilation fans
to control panels and connects control panels to power source; installs air and water filters in completed installation,
injects small amount of refrigerant into compressor to test systems and adds Freon gas to build up prescribed
operating pressure. This mechanic observes pressure and vacuum gauges and adjusts controls to insure proper
operation, tests joints and connections for gas leaks, using gauges or soap-and-water solution, wraps pipes in
insulation batting and secures them in place with cement or wire bands, replaces defective breaker controls,
thermostats, switches, fuses and electrical wiring to repair installed units, may install, repair and service air
conditioners, ranging from fifteen to twenty tons cooling capacity in warehouses and small factory buildings.
23411 HEATING, VENTILATION AND AIR-CONDITIONING MECHANIC (RESEARCH FACILITY)
The Heating, Ventilation, and Air Conditioning Mechanic (Research Facility) installs, modifies and repairs
refrigeration - hermetic, semi-hermetic, mechanical, screw, scroll and centrifugal units to 1100 tons; air
conditioning, ventilation; reverse osmosis systems, computer rooms; process coolers; ice machines; evaporative
cooling; air compressing and related control systems, including pneumatic, DDC, and building control systems
equipment. This person performs difficult installation tasks involving assembly, testing, calibrating, and adjusting of
temperature control and environmental control systems such as air conditioning plants, air environmental control
systems, air distribution systems and complex dual equipment cooling installations, specialized refrigerated
warehouses and facilities, and evaporative mechanical ventilation, and dehumidification systems.
The Heating, Ventilation, and Air Conditioning Mechanic (Research Facility) installs new or repaired component
and performs complex modifications of systems and components in accordance with applicable electrical
publications and directives, and will maintain and repair specialized laboratory equipment such as fume hoods, de-
ionized water systems, bio-clean systems, vacuum systems, cascade refrigeration systems, and laboratory sinks. This
mechanic may perform complex repair of systems component such as compressors, condensers, heat pumps
regulators, fluid and refrigerant gas lines valves, meters, gages, thermostats, pumps, mechanical linkage, and
electrical sensing, switching and controlling devices including pneumatic controls, variable speed drives, digital
controlled devices, electronic, hydraulic heating and cooling and economizer systems
23430 HEAVY EQUIPMENT MECHANIC
The Heavy Equipment Mechanic analyzes malfunctions and repairs, rebuilds and maintains power equipment, such
as cranes, power shovels, scrapers, paving machines, motor graders, trench-digging machines, conveyors,
bulldozers, dredges, pumps, compressors and pneumatic tools. This worker operates and inspects machines or
equipment to diagnose defects, dismantles and reassembles equipment, using hoists and hand tools, examines parts
for damage or excessive wear, using micrometers and gauges, replaces defective engines and subassemblies, such as
transmissions, and tests overhauled equipment to insure operating efficiency. The mechanic welds broken parts and
structural members, may direct workers engaged in cleaning parts and assisting with assembly and disassembly of
equipment, and may repair, adjust and maintain mining machinery, such as stripping and loading shovels, drilling
and cutting machines, and continuous mining machines.
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