4.2.19 CETP Instructor PowerPoint Template

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Performing Pressure Tests on Gas Distribution
Lines
Gas personnel must understand how to perform
pressure tests on gas distribution lines to
ensure the system is gas tight.

• In this module you will learn to identify
• NFPA 54 regulations that apply to pressure
  testing of a propane distribution system
• Basic elements of pressure testing
• Procedures commonly used to pressure test propane
  piping

4.2.19 Student Book ? 2004 Propane Education Research Council Page 1
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NFPA 54 Regulations that Apply to Pressure
Testing
7.1.4.1 Test pressure shall be measured with a
manometer or with a pressure measuring device
designed and calibrated to read, record, or
indicate a pressure loss due to leakage during
the pressure test period. The source of pressure
shall be isolated before the pressure tests are
made. Mechanical gauges used to measure test
pressures shall have a range such that the
highest end of the scale is not greater than 5
times the test pressure.
7.1.4.2 The test pressure to be used shall be no
less than 1-½ times the proposed maximum working
pressure, but not less than 3 psi, irrespective
of design pressure. 7.1.4.3 Test duration shall
be not less than ½ hour for each 500 cubic feet
of pipe volume or fraction thereof. When testing
a system having a volume less than 10 cubic feet
or a system in a single-family dwelling, the test
duration shall be a minimum of 10 minutes. The
duration of the test shall not be required to
exceed 24 hours.
4.2.19 Student Book ? 2004 Propane Education Research Council
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NFPA 54 Regulations that Apply to Pressure
Testing
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. 7.1.1.5 A
piping system shall be tested as a complete unit
or in sections. Under no circumstances shall a
valve in a line be used as a bulkhead between gas
in one section of the piping system and test
medium in an adjacent section, unless two valves
are installed in series with a valved tell tale
located between these valves. A valve shall not
be subjected to the test pressure unless it can
be determined that the valve, including the valve
closing mechanism, is designed to safely
withstand the pressure.
4.2.19 Student Book ? 2004 Propane Education Research Council Pages 1 2
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Identifying Basic Elements of Pressure Testing
Test Medium. According to NFPA 54, 7.1.2, the
test medium shall be air, nitrogen, or carbon
dioxide, or an inert gas. Do not use oxygen or
fuel gas. Test Pressure. NFPA 54 requires a
test pressure that is 1 ½ times the maximum
working pressure for the piping section, but not
less than 3 psig. For example, pipe supplying
propane vapor to a second-stage or 2-PSI service
regulator may have a working pressure of 10 psig.
In this situation, the test pressure is at least
15 psig (1 ½ x 10). However, the second stage
pipe supplying propane to the appliances has an
operating pressure of 11 inches water column. In
this situation, the test pressure is at least 3
psig, and appliances and their controls are not
connected to the piping system during the
test. Test Duration NFPA 54 and most state and
local codes require a 10 minute test duration for
single-family dwellings and small capacity
distribution systems with less than 10 cubic feet
(1,840 lineal feet of 1 steel pipe). However,
if the distribution piping is more than 10 cubic
feet, NFPA 54, requires a test duration of 30
minutes for each 500 cubic feet of piping.
Regardless of size, NFPA 54 states that the
duration of the test need not exceed 24 hours.
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NFPA 54 Regulations that Apply to Pressure
Testing
Pressure Measuring Devices. NFPA 54, 7.1.4.1
requires Test pressure shall be measured with a
pressure measuring device designed and calibrated
to read, record, or indicate a pressure loss due
to leakage during the pressure test period. The
source of pressure shall be isolated before the
pressure tests are made. Mechanical gauges used
to measure test pressures shall have a range such
that the highest end of the scale is not greater
than 5 times the test pressure. For example, a
0-15 psi gauge should be used for a 3 psig
pressure test, while a 0-75 psi gauge is required
for a 15 psig test.
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Procedures Used to Pressure Test Propane Piping
Before testing, check the installation carefully
to be sure it is properly installed and meets
applicable state and local codes and regulations.

• All pipe, tubing, and fittings used in the
  installation must meet the requirements in all
  applicable state and local codes and standards,
  particularly the National Fuel Gas Code, NFPA 54.
  
• For new installations, the underground lines and
  the lines inside buildings must be left uncovered
  for the duration of the pressure testing.
• All aboveground lines must be properly supported
  as necessary, and protected from physical damage.
  
• Before beginning a test, be sure the gauge(s) and
  test fittings are in good condition. Test
  fittings equipped with Schrader valves should be
  fitted with appropriate sealing caps and cap
  gaskets.

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Procedures Used to Pressure Test Propane Piping
Pressure Testing Integral Two-Stage Distribution
Systems 11 Inches Water Column Operating
Pressure Integral 2-Stage Regulator
Description Test Pressure Minimum Test Duration Test Medium PressureMeasuring Device
Before appliances are connected 3 psig minimum 10 minutes Air, nitrogen, or carbon dioxide A pressure gauge designed and calibrated to read, record, or indicate a pressure loss due to leakage during the pressure test period.
Figure 2. Pressure Testing Integral Two-Stage
Distribution Lines Operating Pressure 11
Inches Water Column
This method is intended for testing the main and
branch lines before they are connected to the
appliance shutoff valves and the integral
two-stage regulator. The piping system must
withstand a test pressure of at least 3 psig for
a minimum of 10 minutes without showing any drop
in pressure.
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Procedures Used to Pressure Test Propane Piping
Figure 3. Example of Integral Two-Stage Piping
Diagram
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Procedures Used to Pressure Test Propane Piping
Step 1 Make sure the entire line is disconnected from the propane storage container regulator and the ends of all branch lines are either capped or plugged.
Step 2 Install a test adaptor and suitable gauge at any connection in the piping system.
Step 3 Install in the piping system a pressure-measuring device designed and calibrated to read, record, or indicate a pressure loss caused by leakage.
Step 4 Pressurize the piping system to at least 3 psig. A hand pump may be used, as illustrated in Figure 4. The source of pressure shall be isolated before the pressure test is made.
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Procedures Used to Pressure Test Propane Piping
Step 5 Ensure the pressure on the piping system being pressure tested remains constant for a minimum time period of 10 minutes.
Step 6 If the piping system holds the test pressure for a minimum of 10 minutes without any drop, the piping system is considered gastight. (If the piping system is not considered gastight, take appropriate action to locate the leak and make necessary repairs.)
Step 7 Prepare a record that indicates which portions of the piping system were pressure-tested.
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Procedures Used to Pressure Test Propane Piping
Pressure Testing Two-Stage Distribution Systems
11 Inches Water Column Final Delivery Pressure
1st 2nd Stage Regulators
Description Test Pressure Minimum Test Duration Test Medium PressureMeasuring Device
Buried Distribution Line (before regulator is installed). Not less than 1.5 (1½) times the maximum working pressure of the first stage line. The typical working pressure of the first stage regulator is 10 psig therefore, the test pressure should be at least 15 psig. 10 minutes Air, nitrogen, or carbon dioxide A pressure gauge designed and calibrated to read, record, or indicate a pressure loss due to leakage during the pressure test period.
Second Stage Line, Before appliances are installed. 3 psig minimum 10 minutes Air, nitrogen, or carbon dioxide
Figure 5. Pressure Testing Two Stage
Distribution Lines Appliance Operating Pressure
11" w.c.
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Procedures Used to Pressure Test Propane Piping
Figure 6. Pressure Testing First-Stage Line
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Procedures Used to Pressure Test Propane Piping
Step 1 Disconnect the line from the storage container regulator and the second-stage regulator.
Step 2 Plug or cap the terminating ends of the first-stage line.
Step 3 Install a pressure-measuring device designed and calibrated to read, record, or indicate a pressure loss due to leakage during the pressure test period in the container end of the line.
Figure 7. Installing Test Gauge and Fittings
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Procedures Used to Pressure Test Propane Piping
Step 4 Pressurize the piping system to at least 15 psig. (An air pump may be used, as illustrated in Figure 6.) Then isolate the source of pressure.
Step 5 Ensure the pressure remains constant for a minimum time period of 10 minutes.
Step 6 If the line holds the test pressure without any drop, the line is considered gastight. (If the line is not considered gastight, take appropriate action to locate the leak and make necessary repairs.)
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Procedures Used to Pressure Test Propane Piping
Step 7 Prepare a record indicating the section(s) of pipe tested.
Figure 8. Recording the Pressure Test
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Procedures Used to Pressure Test Propane Piping
Test the second-stage line(s) by using the same
basic method used for integral two-stage systems
(a minimum 3-psig test for 10 minutes).
Figure 9. Pressure Testing Distribution Lines
Downstream of 2nd-Stage Regulator
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Procedures Used to Pressure Test Propane Piping
Pressure Testing 2-Pound Distribution Systems
10 psig buried distribution line pressure and
2-psi delivery pressure to one or more line
regulators controlling 11 inches water column
final delivery pressure. If the system uses a
first-stage and 2-PSI service regulators
connected by a buried distribution line, the
system is tested as a two-stage piping system
(Figure 10).
Figure 10.
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Procedures Used to Pressure Test Propane Piping
Description Test Pressure Minimum Test Duration Test Medium PressureMeasuring Device
Buried Distribution Line (before regulator is installed). Not less than 1.5 (1½) times the maximum working pressure of the first stage line. The typical working pressure of the first stage regulator is 10 psig therefore, the test pressure should be at least 15 psig. 10 minutes Air, nitrogen, or carbon dioxide A pressure gauge designed and calibrated to read, record, or indicate a pressure loss due to leakage during the pressure test period.
Line Connecting 2-PSI Service Regulator to Distribution Manifold. 3 psig minimum 10 minutes Air, nitrogen, or carbon dioxide
Distribution Man-fold and distribution lines to appliances 3 psig minimum 10 minutes Air, nitrogen, or carbon dioxide
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Procedures Used to Pressure Test Propane Piping
Figure 12. Pressure Testing First-Stage Line
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Procedures Used to Pressure Test Propane Piping
Step 1 Disconnect the line from the storage container regulator and the second-stage regulator.
Step 2 Plug or cap the terminating ends of the first-stage line.
Step 3 Install a pressure-measuring device designed and calibrated to read, record, or indicate a pressure loss due to leakage during the pressure test period in the container end of the line.
Step 4 Pressurize the piping system to at least 15 psig. Then isolate the source of pressure.
Step 5 Ensure the pressure remains constant for a minimum time period of 10 minutes.
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Procedures Used to Pressure Test Propane Piping
Step 6 If the line holds the test pressure without any drop, the line is considered gastight. (If the line is not considered gastight, take appropriate action to locate the leak and make necessary repairs. Repeat the pressure test as needed until a gastight condition is maintained.)
Step 7 Prepare a record indicating the section(s) of pipe tested.
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Procedures Used to Pressure Test Propane Piping
To test lines in a 2-psi system that uses a
single line regulator and distribution manifold
Step 1 Remove the line regulator located upstream of the distribution manifold and replace with a pipe nipple. (Figure 13) Verify that all valves at the manifold are manufacturer approved for the pressure that will be used for the test and that the valves are in their open positions.
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Procedures Used to Pressure Test Propane Piping
Step 2 Plug or cap the terminating ends of the lines at appliance locations.
Step 3 Install a pressure-measuring device designed and calibrated to read, record, or indicate a pressure loss due to leakage during the pressure test period in the outside connection where the 2-PSI service regulator is disconnected for the pressure test.
Step 4 Pressurize the piping system to at least 3 psig. Then isolate the source of pressure.
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Procedures Used to Pressure Test Propane Piping
Step 5 Ensure the pressure remains constant for a minimum time period of 10 minutes.
Step 6 If the line holds the test pressure without any drop, the lines and manifold are considered gastight. (If the lines are not considered gastight, take appropriate action to locate the leak and make necessary repairs. Repeat the pressure test as needed until a gastight condition is maintained.)
Step 7 Prepare a record indicating the section(s) of pipe tested.
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Procedures Used to Pressure Test Propane Piping
Figure 14. 2-PSI System with 2 Line Regulators
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Procedures Used to Pressure Test Propane Piping
Figure 15. CSST Multiple Manifold System
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Procedures Used to Pressure Test Propane Piping
Be sure to comply with your companys pressure
testing procedures, along with code requirements
of jurisdictional authorities in your area. Also
read and follow manufacturer recommendations for
pressure testing corrugated stainless steel
tubing as appropriate.
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Time to See If You Got the Key Points of This
Module

• Complete the Review on page 14.
• See if you are ready for the Certification Exam
  by checking off the performance criteria on page
  15.

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