4.2.16 student book © 2004 propane education & research councilpage 1 4.2.16 installing copper...

4.2.16 Student Book © 2004 Propane Education & Research Council

4.2.16Installing Copper Tubing in Distribution Systems

Personnel who install copper tubing are required to know the proper techniques for cutting, bending, joining and protecting copper tubing, as well as the appropriate code requirements.

In this module you will learn to identify:(1) Characteristics and specifications of copper tubing used in

propane vapor distribution systems(2) Common practices used in working with tubing(3) Guidelines for installing copper tubing

4.2.16 Student Book © 2004 Propane Education & Research Council Page 1

Characteristics & Specifications of Copper TubingApproved for Propane

Seamless Copper Water Tubing— Copper water tubing types K and L are designated by ASTM standard sizes, with the actual outside diameter always 1/8 inch larger than the nominal size. Each type consists of a series of

sizes with different wall thickness (Figure1). Copper tubing is ordered by its nominal size.



Figure 1. Dimensions of Nominal Size Copper Tubing (ASTM-B88)

4.2.16 Student Book © 2004 Propane Education & Research Council Pages 2 & 3


Soft Copper Tubing—Since soft copper tubing is flexible and easily bent, proper installation requires it to be supported by clamps and suitable brackets.

Soft copper tubing is most often connected using flared and brazed fittings.

Solder used for brazing copper propane lines must have a minimum melt temperature of 1,000° F.

Soft solder should be used only on water lines and is not permitted for use on gas lines.

Air Conditioning and Refrigeration (ACR ASTM B-280) Tubing— ACR tubing is usually charged with nitrogen gas to keep it clean and dry until it is used. When used for propane distribution, it should have the ends plugged immediately after cutting a length from a piece of stock tubing.

ACR tubing is sized by the actual outside diameter (OD) of the tube.



Figure 2. Common Flare Fittings


Common Practices Used in Working with Tubing

Figure 4. Tubing Cutter

Unrolling Short lengths of tubing are straightened by repeated rolling of the tubing on a flat surface while pressing down on the tubing with the palms of your hands. Longer sections of tubing are straightened by carefully bending the tubing with your hands.

Cutting After the cut is made, remove any metal chips on the outside of the tubing with a file. Also, remove the burrs on the inside of the tubing with a reamer and make a bevel on the leading edge of the flare.

Bending. Although soft tubing can be bent by hand, a tube bending tool should be used to protect the tubing from kinks and flat spots during bending. Two types of tubing benders are the spring‑type bender and the lever‑type bender.



Figure 5. Die Block Flaring Tool

Flaring and Connecting Flared Tubing. In order to flare the end of a piece of soft copper tubing, a special flaring tool called a die block is used to form the flare.

Step 1: Select the appropriate flare nut.

Step 2: Place the flare nut on the tubing before putting the tubing in the die block.

Figure 6. Flared Tubing Connection and Assembly



Step 3: Flare the end of tubing according to the operating instructions for the flaring tool. The following examples illustrate incorrect and correct flaring:

Figure 7. IncorrectlyFormed Tubing Flare–Too Small

Figure 8. IncorrectlyFormed Tubing Flare–Too Large

Figure 9. CorrectlyFormed Tubing Flare



Step 4: Clean the flare nut threads on the flared end of the tubing and the threads on the flare fitting before assembling the flared tubing connection.

Step 5: Tighten the flare nut onto the flare fitting by hand first before using a wrench.

Step 6: Once the flare tubing connection is hand tight, use two wrenches—one to hold the flare fitting and one to tighten the flare nut onto the flare fitting.

Do not over-tighten. Over-tightening can produce a crack in the metal of the flare nut, leading to a split and loss of the gas-tight seal.

Do not use pipe thread sealing compounds on the seats of brass flare fittings. Flared copper connections are metal-to-metal seals that may not seat and seal properly if thread sealing compounds are used.



Figure 10.

Connecting Copper Tubing by Brazing. Silver brazing is another method to connect copper tubing. When silver brazing, follow these steps:

Step 1: Measure, mark and cut the tubing to the required length.

Step 2: Use the reaming tool on the tube cutter to remove the burr from the inside of the tube.

Figure 11.



Figure 12.

Step 3: Clean the inside of each fitting by scouring with a fitting brush. Apply a thin layer of flux to the surfaces to be joined, then slide the tubing ends and fittings together.

Step 4: Apply a thin layer of flux to the silver alloy brazing rod. Hold the tip of the torch flame against the fitting until the flux begins to sizzle, then move the flame around to the other side of the fitting to ensure even heat. (When the flux begins to bubble, the connection should be hot enough for brazing.)

Figure 13.



Figure 14.

Step 5: Touch the end of the brazing filler to the pipe just below the fitting. If it melts and is drawn into the joint, the pipe is sufficiently hot.

Step 6: Quickly apply the brazing filler along both seams of the fitting, allowing it to be drawn into the fitting by capillary action. When correctly brazed, the joint will show a thin bead of silver-colored brazing around each seam.

Figure 15.



Figure 16.

Step 7: Allow the joint to cool until the brazing material has a frosty appearance rather than a shiny silver color one. Then, wipe away any excess material with warm water, a wet cloth, and a brush. (Brazing filler will harden in a minute or less if the joint has not been overheated.)


Guidelines for Installing Copper Tubing

Buried Distribution Lines— Where copper tubing is used in an underground tank installation, a dielectric union should be installed at the building service entrance to electrically isolate the copper tubing from steel pipe or tubing used in the building distribution lines. Non-conductive insulating material should also be installed to prevent contact between the copper tubing and the steel of the underground tank, dome, and riser.

Buried copper tubing should be one continuous piece. Buried brass fitting joints should be avoided.

Distribution Lines Inside Homes and Businesses

• In accordance with NFPA 54, 2002, 6.3.2, flared connections are not permitted in concealed spaces, while brazed connections are permitted.

• Unprotected copper tubing should not be used in wall partitions or other locations that potentially subject it to puncture by nails, screws or other fasteners. If copper is located where it is subject to potential puncture or other damage, it must be a single unsecured run and protected by a minimum 0.0508 inch thick steel pipe casing or suitable metal plate strike barrier.



Distribution Lines Inside Homes and Businesses

• Copper tubing cannot be continually bent back and forth without eventual breakage. For this reason, it must not be used to connect appliances subject to being moved for cleaning or other purposes by the customer. The bending action and stress on the tubing is especially severe at the points where the connections are made.

• Installers must exercise care when flaring copper tubing. If a flare is made that contains splits or other imperfections, or is too large or too small for the flare nut, it must be cut off, and a proper flare made. Because flared copper tubing joints are metal-to-metal formed seals, do not use pipe thread sealing compounds. Also, know how to properly tighten brass fittings to assure gas-tight joints in copper lines without splitting the tubing or flare nut.


Guidelines for Installing Copper Tubing Distribution Lines Inside Homes and Businesses

NFPA 54

2002

5.6.5 Workmanship and Defects. Gas pipe, tubing, and fittings shall be clear and free from cutting burrs and defects in structure or threading and shall be thoroughly brushed, and chip and scale blown. Defects in pipe, tubing, and fittings shall not be repaired. Defective pipe, tubing, and fittings shall be replaced.

7.1.1.1 Prior to acceptance and initial operation, all piping installations shall be inspected and pressure tested to determine that the materials, design, fabrication, and installation practices comply with the requirements of this code.

7.1.1.3 Where repairs or additions are made following the pressure test, the affected piping shall be tested. Minor repairs and additions are not required to be pressure tested provided that the work is inspected and connections are tested with a non-corrosive leak-detecting fluid or other leak-detecting methods approved by the authority having jurisdiction.

7.1.1.4 Where new branches are installed from the point of delivery to new appliance(s), only the newly installed branch(es) shall be required to be pressure tested. Connections between the new piping and the existing piping shall be tested with a non-corrosive leak-detecting fluid or approved leak-detecting methods.



Figure 17. Sediment Trap (as shown in Figure 8.5.7 in NFPA 54, 2002 edition)

G a s s u p p l y i n l e t

Toe q u i p m e n ti n l e t

P i p e t e e

C a p

P i p e n i p p l e 3 i n c h e sm i n i m u m

8.5.7 Sediment Trap. If there is no sediment trap, one shall be installed as close to the inlet of the equipment as practicable at the time of equipment installation. The sediment trap shall be either a tee fitting with a capped nipple in the bottom outlet as illustrated in Figure 8.5.7, or another device recognized as an effective sediment trap. Illuminating appliances, ranges, clothes dryers, decorative appliances for installation in vented fireplaces, gas fireplaces, and outdoor grills shall not be required to be so equipped.

4.2.16 Student Book © 2004 Propane Education & Research Council Pages 13 - 16

Time to See If You Got the Key Points of This Module…

• Complete the Review on pages 13 & 14.

• See if you are ready for the Certification Exam by checking off the performance criteria on pages 15 & 16.

4.2.16 student book © 2004 propane education & research councilpage 1 4.2.16 installing copper...

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