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HVACR316 - Piping

Steel PipingCopper TubingOther Materials

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Steel Piping

• Manufactured steel pipe application depends partially on the type of coating that is applied (if any) when it comes from the furnace, and whether or not it is threaded or bundled.

• Pipes that come straight from the furnace and have no threads are dipped into an inexpensive, varnish-like material to help prevent rust.

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Steel Piping

• This coating lasts a short time; pipe with this coating is called black steel pipe PE (PE means plain end).

• The same pipe is also manufactured with both ends threaded, coated with the same material and called black steel pipe T&C (T&C means threaded with coupling).

• Another pipe category is black steel pipe that has been ‘hot-dipped galvanized.’

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Steel Piping

• Steel pipe comes in lengths of 21 feet.– Pipe that ranges from 1/8” to 12” in

diameter is named by its inside diameter (ID).

– Pipe larger than 12 inches in diameter is named by its outside diameter (OD).

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Steel Piping

• Steel pipe has different schedule numbers of pipe wall thickness.– Wall thickness is called schedule, and

goes from 10 through 160.– The American National Standards

Institute (ANSI) established the pipe wall thickness (schedule).

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Steel Piping• Cutting and Joining Steel Piping

– After the correct measurements have been made on a pipe the next step is to cut the pipe.

– After cutting the pipe the next step is to ream the burr from the pipe.

– If a burr is left intact, it reduces the pipe diameter, cause turbulence, and wear at the pipe end due to the oscillating fluid.

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Steel Piping

• ANSI also sets the standards for threads and fittings.– The types are designated by

combinations of certain code letters.– NPT designates American Standard

(national) taper pipe threads; this is the most widely used type.

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Steel Piping

• Fittings– Steel fittings are of the “malleable” type.– Malleable (shapeable) is a form of iron

used in the manufacture of fittings.• Malleable fittings are made of an iron alloy

that is easily shaped or machined for threading and tapping purposes.

• Malleable fittings will not break easily.

• Malleable fittings will bend before they crack.

• They are cast with a bead on the edge for better gripping with a pipe wrench.

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Steel Piping

• When reading a tee;– Read the straight through size.– Then the branch – If all openings are the same size, the tee

is simply called by that size.

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Steel Piping• Galvanic Action (Electrolysis)

– Galvanic action is a chemical reaction between two dissimilar metals (such as iron and copper) when the metals are placed in a solution in which electron transfer can occur.

– If a copper male adaptor is screwed into a female galvanized fitting, a reaction occurs in the presence of fresh water.

– The copper and iron form a short circuited battery that eventually leads to corrosion of the iron.

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Steel Piping• Galvanic action, cont’d.

– Joining two dissimilar metals can be a problem.

– Reaction occurs only in the presence of a fresh water supply, and with two dissimilar metals electrically connected together.

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Steel Piping• Major Die Sizes

Sizes (ID) Threads Inches Per Inch 1/8 27 1/4 3/8 18 1/2 3/4 14 1, 1 ¼ , 1 ½ ,2 11 ½ 2 ½ or over 8

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Steel Piping

• Other Types of Piping:– Cast iron piping; used for waste and

vent piping.– Copper Tube; has a wide range of uses.– Black Pipe; used for natural gas.

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Hard and Soft Drawn Copper

• Hard drawn copper is referred to as copper tube.– Measured by its ID – ID ranges from ½ to 12”

• Soft drawn copper is referred to as copper tubing.

• They can be identified either by the manufacturer’s name running the length of the tube, the color of stripe on the tube, or the letter on the tube.

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Copper Tubing – Soft Drawn

• Soft drawn copper tubing is used in most household and light commercial applications.

• Because it is annealed (soft and bendable), copper tubing is easy to form into a tight radius using a bending tool.

• Also because it is annealed, its flexibility often eliminates the need for fittings which may cause leaks in the system.

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Soft Drawn Copper Tubing

• Soft copper tubing comes in several designations: K, L, M, DWV, and ACR.

• Type K is the heaviest wall tubing.– It is also available in hard drawn

temper. – It is available in diameters from ¼”

to 12” and in lengths up to 20’.– Its color code is a green stripe and

lettering.

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Soft Drawn Copper Tubing

• Type L is medium thickness wall tubing.– Is available in the same configurations as

Type K.– Its color code is a blue stripe and

lettering.

• Type M is a thinner wall tubing.– Is available in hard temper only, in 20’

lengths.– Its color code is a red stripe and lettering.

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Soft Drawn Copper Tubing

• DWV Tube is the thinnest wall tubing.– Is suitable for drain, waste, and vent

only.– Is available in diameters of 1 ½” to

8”, and 20’lengths.– Its color code is yellow stripe and

lettering.

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Soft Drawn Copper Tubing

• ACR Tubing:– Is copper tubing for air conditioning and

refrigeration.– It is Type L tubing that is shipped from the

factory already cleaned and dried, with sealed ends. Packaged in flat cardboard cartons.

– Also used for medical gases.– Usually available in 50’or 60’ coils.– Measured by its OD (1/8” to 7/8”)

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Other Tubing and Piping• PVC (Polyvinyl Chloride)

– PVC is a tough and highly chemical-resistant material.

– PVC is used in highly corrosive applications, such as acids, alkalis, alcohols, salts, and other chemicals.

– It is also used in oil lines, gas transmission, and salt-water disposal systems.

– PVC is impervious to sunlight deterioration.

– It will not spark when struck, and is safe around explosives and flammable vapors.

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Other Tubing and Piping• PVC (Polyvinyl Chloride), cont’d.

– The working strength is affected by temperature.

– Therefore, pressure ratings are decreased at higher temperatures.

– PVC colors are ivory, grey, white.– PVC is available in three pipe schedules

40, 80, 120.

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Other Tubing and Piping• ABS (Acrilonitrile Butadiene Styrene)

– Applications for ABS are similar to PVC.– It is suitable for inorganic acids, salts,

hydrocarbons, glycols, and some alcohols – It is also good for transportation of salt

water, crude oil, gas; used extensively for sewage systems.

– ABS has good chemical resistance, is tough, and has excellent tensile strength.

– ABS by nature is ivory colored; carbon black is added to increase resistance to ultraviolet deterioration.

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Other Tubing and Piping

• Polyethylene (PE)– PE is produced under extremely high

temperatures and pressures.– It is preferred over other plastics for high

pressures, because of its burst strength and easy installation.

– PE is made in clear form, carbon black dye is added to improve resistance to sunlight.

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Steel Piping• Polyethylene (PE), cont’d.

– It is usually sold in a coil form.

– PE is used extensively for jet wells, water supply systems, and sprinkler systems.

– Found to be well-suited for burial because of its high crush resistance.

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Other Tubing and Piping• CPVC (Chlorinated Polyvinyl Chloride)

– CPVC is used in water distribution systems for hot and cold supplies.

– Up to 100 pounds of maximum working pressure at 180°F.