单项选择题
Some chloronated flourocarbon refrigerants may decompose into a toxic irritating gas if it is （）.
A.stored at temperatures below 60 degrees Fahrenheit
B.charged into a system having copper fittings
C.allowed to mix with compressor oil
D.exposed to an open flame or hot surface
相关考题
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单项选择题
A refrigeration system contaminated with moisture can be affected by （）.
A.acid formation
B.sludge formation
C.ice in the expansion valve
D.All of the above -
单项选择题
R-12 is generally considered to be a safe, nontoxic, nonflammable, and non-explosive refrigerantIt can, however, become highly toxic when （）.
A.superheated outside the system
B.in contact with an open flame
C.heated to the boiling point
D.All of the above -
单项选择题
Which of the following statements is/are true regarding hydraulic pumps in general? （）
A.Variable volumes can be obtained with gear pumps only by variation of the pump drive speed
B.A radial piston pump houses sliding pistons in a stationary cylinder block through which passes a rotating pintle or ported shaft
C.The amount of fluid displaced per revolution of an axial piston rotary pump is dependent on the angle formed between the cylinder block and valve plate
D.All of the above
