Prior to acceptance and initial
operation, piping installations shall be visually inspected and
pressure-tested to determine that the materials, design, fabrication,
and installation practices are in accordance with the requirements
of this code. [NFPA 54:8.1.1.1]
Inspection shall
consist of visual examination during or after manufacture,
fabrication, assembly, or pressure tests. [NFPA
54:8.1.1.2]
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 noncorrosive
leak-detecting fluid or other leak-detecting methods
approved by the Authority Having Jurisdiction. [NFPA
54:8.1.1.3]
Where new branches are installed
to new appliances, the newly installed branches shall be required to be pressure-tested. Connections between
the new piping and the existing piping shall be
tested with a noncorrosive leak-detecting fluid or approved
leak-detecting methods. [NFPA 54:8.1.1.4]
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 "telltale" located between these valves. A valve shall not be subjected to the test pressure unless it
is determined that the valve, including the valve-closing
mechanism, is designed to safely withstand the pressure.
[NFPA 54:8.1.1.5]
Regulator and valve
assemblies fabricated independently of the piping system
in which they are to be installed shall be permitted to
be tested with inert gas or air at the time of fabrication.
[NFPA 54:8.1.1.6]
The test medium shall be air, nitrogen,
carbon dioxide, or an inert gas. OXYGEN
SHALL NEVER BE USED. [NFPA 54:8.1.2]
Test preparation shall comply with
Section 1213.2.1 through Section 1213.2.6.
Pipe joints, including welds, shall
be left exposed for examination during the test.
Exception: Covered or concealed pipe end joints that have been previously tested in accordance with this code. [NFPA 54:8.1.3.1]
Exception: Covered or concealed pipe end joints that have been previously tested in accordance with this code. [NFPA 54:8.1.3.1]
Expansion joints shall be
provided with temporary restraints, where required, for
the additional thrust load under test. [NFPA 54:8.1.3.2]
Appliances and
equipment that are not to be included in the test shall be either
disconnected from the piping or isolated by blanks,
blind flanges, or caps. Flanged joints at which blinds are
inserted to blank off other equipment during the test shall
not be required to be tested. [NFPA 54:8.1.3.3]
Where the piping system is connected to appliances or
equipment designed for operating pressures of less than the
test pressure, such appliances or equipment shall be isolated
from the piping system by disconnecting them and
capping the outlets. [NFPA 54:8.1.3.4]
Where the piping system is connected
to appliances or equipment designed for operating pressures
equal to or greater than the test pressure, such appliances
and equipment shall be isolated from the piping
system by closing the individual appliance or equipment
shutoff valve(s). [NFPA 54:8.1.3.5]
Testing of piping systems shall be performed
in a manner that protects the safety of employees
and the public during the test. [NFPA 54:8.1.3.6]
This inspection shall include an air,
CO2, or nitrogen pressure test, at which time the gas piping shall
stand a pressure of not less than 10 psi (69 kPa) gauge pressure.
Test pressures shall be held for a length of time satisfactory to
the Authority Having Jurisdiction, but in no case less than 15
minutes with no perceptible drop in pressure. For welded piping,
and for piping carrying gas at pressures in excess of 14
inches water column pressure (3.5 kPa), the test pressure shall
be not less than 60 psi (414 kPa) and shall be continued for a
length of time satisfactory to the Authority Having Jurisdiction, but in no case for less than 30 minutes. For CSST carrying gas
at pressures in excess of 14 inches water column (3.5 kPa) pressure,
the test pressure shall be 30 psi (207 kPa) for 30 minutes. These tests shall be made using air, CO2, or nitrogen pressure
and shall be made in the presence of the Authority Having Jurisdiction.
Necessary apparatus for conducting tests shall be furnished
by the permit holder. Test gauges used in conducting tests
shall be in accordance with Section 318.0.
The piping system
shall withstand the test pressure specified without showing evidence
of leakage or other defects. Reduction of test pressures
as indicated by pressure gauges shall be deemed to indicate the
presence of a leak unless such reduction is readily attributed to
some other cause. [NFPA 54:8.1.5.1]
The leakage shall be located
by means of an approved gas detector, a noncorrosive
leak detection fluid, or other approved leak detection
methods. Matches, candles, open flames, or other methods
that provide a source of ignition shall not be used.
[NFPA 54:8.1.5.2]
Where leakage or other defects
are located, the affected portion of the piping system
shall be repaired or replaced and retested. [NFPA 54:8.1.5.3]
Leak checks using fuel gas
shall be permitted in piping systems that have been pressure-tested
in accordance with Section 1213.0. [NFPA 54:8.2.1]
During the process of turning
gas on into a system of new gas piping, the entire system
shall be inspected to determine that there are no open
fittings or ends and that valves at unused outlets are
closed and plugged or capped. [NFPA 54:8.2.2]
Immediately after the gas is
turned on into a new system or into a system that has
been initially restored after an interruption of service, the
piping system shall be checked for leakage. Where leakage
is indicated, the gas supply shall be shut off until the
necessary repairs have been made. [NFPA 54:8.2.3]
Appliances and equipment shall not be placed in
operation until after the piping system has been checked
in accordance with Section 1213.5.2; connections to the
appliance are checked for leakage; and purged in accordance
with Section 1213.6. [NFPA 54:8.2.4]
The purging of piping shall
be in accordance with Section 1213.6.1 through Section
1213.6.3. [NFPA 54:8.3]
The purging of piping systems shall be in accordance
with the provisions of Section 1213.6.1.1 through
Section 1213.6.1.4 where the piping system meets either
of the following:
For SI umts: 1 inch = 25 mm, 1 foot = 304.8 mm
* CSST EHD size of 62 is equivalent to nominal 2 inches (50 mm) pipe or tubing size.
- The design operating gas pressure exceeds 2 psig (14 kPa).
- The piping being purged contains one or more sections of pipe or tubing meeting the size and length criteria of Table 1213.6.1. [NFPA 54:8.3.1]
| NOMINAL PIPING SIZE (inches) |
LENGTH OF PIPING (feet) |
| ≥ 21/2 < 3 |
> 50 |
| ≥ 3 < 4 |
> 30 |
| ≥ 4 < 6 |
> 15 |
| ≥ 6 < 8 |
> 10 |
| ≥ 8 |
Any length |
* CSST EHD size of 62 is equivalent to nominal 2 inches (50 mm) pipe or tubing size.
Where existing
gas piping is opened, the section that is opened shall
be isolated from the gas supply and the line pressure
vented in accordance with Section 1213.6.1.3.
Where gas piping meeting the criteria of Table
1213.6.1 is removed from service, the residual fuel
gas in the piping shall be displaced with an inert gas.
[NFPA 54:8.3.1.1]
Where gas piping
containing air and meeting the criteria of Table
1213.6.1 is placed in operation, the air in the piping
shall first be displaced with an inert gas. The inert
gas shall then be displaced with fuel gas in accordance
with Section 1213.6.1.3. [NFPA 54:8.3.1.2]
The open end of a piping system being pressure
vented or purged shall discharge directly to an outdoor
location. Purging operations shall comply with
the following requirements:
- The point of discharge shall be controlled with a shutoff valve.
- The point of discharge shall be located not less than 10 feet (3048 mm) from sources of ignition, not less than 10 feet (3048 mm) from building openings, and not less than 25 feet (7620 mm) from mechanical air intake openings.
- During discharge, the open point of discharge shall be continuously attended and monitored with a combustible gas indicator that is in accordance with Section 1213.6.1.4.
- Purging operations introducing fuel gas shall be stopped where 90 percent fuel gas by volume is detected within the pipe.
- Persons not involved in the purging operations shall be evacuated from areas within 10 feet (3048 mm) of the point of discharge. [NFPA 54:8.3.1.3]
Combustible
gas indicators shall be listed and shall be
calibrated in accordance with the manufacturer's instructions.
Combustible gas indicators shall numerically display a volume scale from 0 percent to 100
percent in 1 percent or smaller increments. [NFPA
54:8.3.1.4]
The purging of piping systems shall
be in accordance with the provisions of Section
1213.6.2.1 where the piping system meets both of the
following:
- The design operating pressure is 2 psig (14 kPa) or less.
- The piping being purged is constructed entirely from pipe or tubing not meeting the size and length criteria of Table 1213.6.1. [NFPA 54:8.3.2]
The piping system
shall be purged in accordance with one or more of
the following:
- The piping shall be purged with fuel gas and shall discharge to the outdoors.
- The piping shall be purged with fuel gas and shall discharge to the indoors or outdoors through an appliance burner not located in a combustion chamber. Such burner shall be provided with a continuous source of ignition.
- The piping shall be purged with fuel gas and shall discharge to the indoors or outdoors through a burner that has a continuous source of ignition and that is designed for such purpose.
- The piping shall be purged with fuel gas that is discharge to the indoors or outdoors, and the point of discharge shall be monitored with a listed combustible gas detector in accordance with Section 1213.6.2.2. Purging shall be stopped where fuel gas is detected.
- The piping shall be purged by the gas supplier in accordance with written procedures. [NFPA 54:8.3.2.1]
Combustible
gas detectors shall be listed and shall be calibrated or
tested in accordance with the manufacturer's instructions.
Combustible gas detectors shall be capable of
indicating the presence of fuel gas. [NFPA 54:8.3.2.2]
After
the piping system has been placed in operation, appliances
and equipment shall be purged before being placed
into operation. [NFPA 54:8.3.3]