Heavy wear in a particular area of the inner circumference of a packing ring may be caused by （）.

An internal bypass is provided on some hydraulic system suction strainers to help reduce the possibility of （）.

Pitting in the suction areas of a centrifugal pump bronze impeller is usually caused by （）.

One cause of high head pressure occurring in a refrigeration system can be （）.

The amount of fluid friction or internal friction inherent in a mineral lubricating oil is reflected as a measure of its （）.

The usual symptoms of cavitation in a centrifugal pump is （）.

If the viscosity of the liquid being transferred remains constant as the discharge pressure increases, the rotary pump （）.

The rate of heat transfer between the hot and cold fluids passing through a shell-and-tube type heat exchanger will （）.

Thermostatic expansion valves can be adjusted for （）.

If the thermal bulb of an expansion valve is incorrectly placed at the center of the coil instead of the end, it will （）.