Lesson 1 - Piping Materials and Fittings
Topics:
Material compatibility; Sizing; Oil migration; Pipe vs tubing; Schedules and codes; Valves; Fittings; Cutting and joining pipe; Tubing materials and sizes; Cutting, flaring, bending, and joining tubing
Learning Objectives:
– Name the three main lines of piping in a refrigeration system.– Explain why air conditioning and refrigeration piping must be sized correctly.
– Contrast pipe and tubing and explain why tubing is often preferred over piping.
– Explain how pipe is classified according to schedule.
– Name three methods of joining steel pipe.
– Explain how tubing is cut, flared, bent, and joined.
– Describe the step-by-step procedure for making a brazed joint.
Lesson 2 - Discharge Line
Topics:
Refrigerant condition; Pressure drop; Oil circulation; Piping layout, sizing; Refrigerant migration; Accessories
Learning Objectives:
– List the four functions of the discharge line in a refrigeration piping system.– Explain the importance of pressure drop in piping and its effects on system operation.
– Define the term entrainment and explain why entrainment of oil is important.
– State the flow velocity needed for refrigerant vapor to entrain oil in horizontal piping and in vertical risers.
– Name some practical steps you can take to assure a good flow of refrigerant in horizontal piping.
– Describe ways of preventing refrigerant and oil migration to the compressor.
– Name and explain the purposes of three discharge-line accessories.
Lesson 3 - Liquid Line
Topics:
Refrigerant condition; Pressure drop; Oil circulation; Piping layout and sizing; Liquid receiver; Components, accessories, and insulation
Learning Objectives:
– Name the functions of the liquid line.– Explain why it is desirable to have subcooling in the liquid line.
– Describe the effects of pressure drop in the liquid line on the operation of a refrigerant system.
– Describe the effects of flash gas formation on the performance of the system.
– Explain the purpose of a liquid receiver.
– Explain why each of the following devices is used in the liquid line: sight glass, solenoid valve, check valve.
Lesson 4 - Suction Line
Topics:
Lubricating oil; Pressure drop; Accumulators; Heat exchangers; Controls; Valves; Filters; Vibration eliminators; Insulation
Learning Objectives:
– Describe the functions of the suction line, its structural demands, and special design features.– Explain why suction lines are pitched down toward the compressor.
– Explain how a double suction riser moves oil along with the refrigerant.
– Explain the function of an accumulator and a heat exchanger in a suction line.
– Describe the basic differences between evaporator pressure regulators and crankcase pressure regulators.
– Explain why it is necessary to insulate the suction line.
– Explain how a suction line for multiple compressors differs from a suction line for a single compressor.
Lesson 5 - Piping Systems Maintenance
Topics:
Dirt and scale; Piping expansion; Supports; Vibration; Corrosion; Leaks; Liquid hammer; Thermal insulation; Troubleshooting
Learning Objectives:
– Name at least four factors that cause piping problems and can lead to operating problems.– Explain why cleanliness is essential when assembling refrigeration piping.
– Name at least three ways to allow for the expansion of piping.
– Describe the various ways of supporting horizontal and vertical pipe runs.
– Describe the damage that can be caused by vibration and tell how to protect piping from it.
– Define corrosion and explain how it can be prevented in refrigerant and water piping.
– Explain the importance of thermal insulation for refrigeration system piping.
