4.2.17 CETP Instructor PowerPoint Template

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Installing Steel Piping in Vapor Distribution
Systems
Installing steel piping in customer gas appliance
distribution systems requires an understanding of
proper pipe fitting skills and fuel gas code
requirements.

• In this module you will learn to identify
• Pipe size and pipe fittings commonly used in
  propane vapor distribution systems
• Common piping procedures

4.2.17 Student Book ? 2004 Propane Education Research Council Page 1
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Pipe Pipe Fittings Used in Propane Vapor
Systems
2.4.2 specifies that metallic pipe shall be
wrought iron or steel (black or galvanized),
brass, or copper. Wrought iron or steel pipe
must comply with the listed ASME or ASTM
standards.
5.8.3.1
Pipe Sizing. Propane piping must be of such size
and installed to provide a supply of propane
sufficient to meet the maximum demand without
undue loss of pressure between the point of
delivery and the gas utilization
equipment. Standard pipe of steel or wrought iron
up to 12 inches in diameter is specified by its
nominal inside diameter (ID). The actual inside
diameter of the pipe will vary depending on the
wall thickness of the pipe.
4.2.17 Student Book ? 2004 Propane Education Research Council Page 1
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Pipe Pipe Fittings Used in Propane Vapor
Systems
The inside diameter of Schedule 40 1
inch pipe is more than 1 inch (1.049). The
inside diameter of a Schedule 80 1 inch
pipe is less than 1 inch (0.951). A schedule
number is used as a means of specifying the wall
thickness of pipe. The National Fuel Gas Code,
NFPA 54, requires that steel and wrought iron
pipe be at least of standard weight (Schedule 40)
in pressure regulated vapor systems.
Types of Pipe Fittings. Pipe fittings are the
components used in making turns or connecting
sections of piping systems. In propane piping
systems, only steel and malleable iron fittings
are used with steel or wrought iron pipe. Cast
iron shall not be used.
4.2.17 Student Book ? 2004 Propane Education Research Council Pages 2 3
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Pipe Pipe Fittings Used in Propane Vapor
Systems
Figure 2. Screw Type Pipe Fittings
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Pipe Pipe Fittings Used in Propane Vapor
Systems
Pipe Nipple. Pipe nipples are short pieces of
pipe ranging in length from "close" to ten
inches. The most common nipples are used in even
inch lengths although they may be obtained in
half inch lengths.
Pipe Elbow. "Elbows" (ells) provide a turn in
the piping. One type consists of two openings,
each with a female thread. A 90o elbow provides
a 90o bend, while a 45o elbow makes a 45o turn.
A 1" x 3/4" - 90o elbow would refer to an ell
with one 1" opening, one 3/4" opening and
consisting of a 90o bend.
Figure 4. Reducing Pipe Elbow 1 1/4 X ¾
4.2.17 Student Book ? 2004 Propane Education Research Council Page 4
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Pipe Pipe Fittings Used in Propane Vapor
Systems
Pipe Tee. "Tees" provide for a branch connection
in the piping. They have three openings, each
with a female thread. Street tees may also be
used and they consist of two female threads and
one male thread. All three openings may be the
same size or, if it is a reducing tee, the
openings will be of different sizes. To identify
the tee, first specify the run (straight through)
dimension, followed by the side outlet (branch)
dimension. Running Tee. A "running" connection
of a tee consists of connecting one end opening
of the tee to a fitting or a piece of
pipe. Bullhead Tee. A "bullhead" connection of a
tee means connecting a fitting or a piece of pipe
in the side opening of the tee.
4.2.17 Student Book ? 2004 Propane Education Research Council Page 5
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Pipe Pipe Fittings Used in Propane Vapor
Systems
Pipe Cap. "Caps," as illustrated in Figure 8,
are used to close the pipe cap end of a
pipe. Reducing Coupling. "Couplings" consist of
two openings, each with a female thread. They
are used to connect (couple) two male threads.
Reducing couplings are used to connect two male
threads of different sizes. Straight Coupling.
The straight coupling illustrated in Figure 10
joins two pipes of the same size together. Pipe
Plug. "Plugs," as illustrated in Figure 11, are
used to close a tapping in a fitting.
4.2.17 Student Book ? 2004 Propane Education Research Council Pages 5 6
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Pipe Pipe Fittings Used in Propane Vapor
Systems
Union. Fittings know as "unions" (Figure 12)
permit a quick connection or disconnection of a
fuel line. A union consists of two union halves
and a collar. The two union halves are made
tight by the tightening of the collar. Unions
with an insulator between the two halves
(dielectric union) are used when joining
dissimilar metals to help prevent electron flow
(corrosion). A "ground joint" union may be used
on gas piping where cathodic protection is not
required. The two halves of the "ground joint"
union are made tight by a metal-to-metal seal and
no gasket is required. However, the union faces
are factory-ground to fit. Therefore, the halves
are not interchangeable.
4.2.17 Student Book ? 2004 Propane Education Research Council Page 7
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Identifying Common Piping Procedures
Care of Pipe and Pipe Fittings. Pipe should be
handled with sufficient care to help prevent
damage to the male threads. Pipe with stripped,
chipped, corroded, or otherwise damaged threads
must not be used. Pipe Vise. The pipe vise is
used to hold the pipe during the cutting and
threading operation.
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Identifying Common Piping Procedures
Measuring Pipe Lengths. Allowances must be made
for pipe fittings when cutting pipe to conform to
a piping plan. Some pipe fittings have been
standardized, so when standard fitting allowances
are used it is only necessary to measure to the
center of the fitting. The "fitting allowance"
(Figure 14) is the distance from the end of the
pipe to the center opening of the fitting.
Figure 14. Fitting Allowance Make-Up
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Identifying Common Piping Procedures
Figure 15. Average Make-up Distances
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Identifying Common Piping Procedures
The "end-to-end" measurement (Figure 16) is equal
to the length of a piece of pipe with no
fittings. The "end-to-center" measurement is
equal to the distance between one end of the pipe
and the center of the opening of the fitting
attached to the other end (Figure 17). The
"center-to-center" measurement is equal to the
distance between the center of the openings of
two fittings connected by a piece of pipe (Figure
18).
Figure 16. End-to-End Measurement
Figure 17. End-to-Center Measurement
4.2.17 Student Book ? 2004 Propane Education Research Council Pages 9 10
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Identifying Common Piping Procedures
Pipe Cutters. There are two types of pipe
cutters commonly used. They are identified by
the number of cutting wheels. Single wheel
cutters (Figure 19) have only one cutting wheel
and two or more roller wheels. Care must be used
to square the pipe cutter when starting the cut
or a double cut or screw cut may result.
Inspect the first cut and make certain that all
cutting wheels are in the same groove. This is
called "tracking." Special care must be taken
when using three and four wheel cutters to be
sure that they track properly. Always rotate
cutter handle towards the open face of cutter.
4.2.17 Student Book ? 2004 Propane Education Research Council Page 10
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Identifying Common Piping Procedures
Pipe Reamer. When a pipe is cut using a pipe
cutter, a metal burr is left on the inside wall
of the pipe. The burr is removed with a pipe
reamer (Figure 20). The point of the pipe reamer
is inserted into the end of the pipe and rotated
to remove the burrs from the wall.
Figure 20. Pipe Reamer
4.2.17 Student Book ? 2004 Propane Education Research Council Page 11
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Identifying Common Piping Procedures
Figure 21. Pipe Threads
4.2.17 Student Book ? 2004 Propane Education Research Council Pages 12
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Identifying Common Piping Procedures
Pipe Threader. Pipe and fitting threads must
comply with the American Standard for pipe
threads. The standard pipe thread has a taper of
3/4" per foot. A good set of pipe threads using
1/2," 3/4," and 1" pipe is about 10 complete
threads.
Pipe threading tools are composed of two parts,
dies, and stocks. The die is the part of the
pipe threading tool that does the cutting of the
male threads. Each die assembly has four sets of
cutting edges that must be mounted in the proper
sequence. This will allow each set to cut a
little deeper than the set preceding it. The
cutting edges must also be positioned properly,
so each will track in the same thread. Since the
cutting edges are on a taper, each set must be
installed so the pipe will enter the larger end
first.
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Identifying Common Piping Procedures
Pipe Threader. Before starting the threading, a
few drops of oil should be put on the pipe to
lubricate the stock guide. As soon as the die is
started on the pipe, additional cutting oil
should be put on the threading area to ease
cutting and to reduce wear on the cutting edges.
Additional cutting oil should also be applied
several times during the cutting of a complete
set of threads. Always use cutting oil do not
use a substitute. The die should be run onto the
pipe until the end of the pipe is even or
protrudes about two threads beyond the back of
the die.
4.2.17 Student Book ? 2004 Propane Education Research Council Page 13
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Identifying Common Piping Procedures
Making Threaded Pipe Connections. The most
important objective in any gas piping
installation is to be sure that the piping
connections are gastight.
Step 1 Clean the threads of both the pipe and fitting to be assembled.
Step 2 Once cleaned, check the threads carefully to be sure they are in good condition.
Step 3 Properly apply a thread sealing compound (pipe joint compound) or pipe sealant tape to the male threads only. Do not apply sealing compound to the first two or three threads.
Step 4 Secure all sections of pipe before making the connection.
4.2.17 Student Book ? 2004 Propane Education Research Council Page 14
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Identifying Common Piping Procedures
Making Threaded Pipe Connections.
Step 5 Assemble the fitting on the pipe by hand and use a pipe wrench to complete the connection.
Step 6 After the piping system is completely assembled, each outlet, including a valve, must be closed gas-tight with a threaded plug or cap immediately after installation as required by 6.7.2.1 of NFPA 54, 2002 edition.

• New piping and modified branches of existing
  piping systems must be successfully pressure
  tested at 1½ times normal working pressure, but
  no less than 3 psig for a minimum of 10 minutes
  prior to their connection to gas appliances, as
  prescribed by Chapter 7 of NFPA 54.

Step 7 A leak check of the complete vapor distribution system, including appliance connections must be performed before the system is placed into service.
4.2.17 Student Book ? 2004 Propane Education Research Council Page 15
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Identifying Common Piping Procedures
Installing Piping Outside the Building. Two
basic factors to consider when burying piping are
the pipe cover requirements and protection
against corrosion.

1. Cover Requirements Underground piping systems
   should have at least 18 inches (46 cm) of cover.
   With certain exceptions, cover may be reduced to
   12 inches (30 cm). If 12 inches (30 cm) cannot
   be maintained, the pipe must be installed in
   conduit or bridged (shielded).
2. Protection Against Corrosion Buried gas piping
   must also be protected against corrosion in an
   approved manner. Also, when dissimilar metals
   are joined underground, an insulating coupling or
   fitting shall be used.

4.2.17 Student Book ? 2004 Propane Education Research Council Page 15
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Identifying Common Piping Procedures
Installing Piping Inside the Building. All
propane piping installed inside a structure must
meet state and local regulations, as well as
national standards to insure a proper
installation. Piping supports must be of adequate
strength and located at proper intervals.
Figure 23. Piping Support Spacing Intervals
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Identifying Common Piping Procedures
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.
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Identifying Common Piping Procedures
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.
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Time to See If You Got the Key Points of This
Module

• Complete the Review on pages 19 - 21.
• See if you are ready for the Certification Exam
  by checking off the performance criteria on page
  22 23.

4.2.17 Student Book ? 2004 Propane Education Research Council Pages 19 - 23