(1) Pressure
testing required. After assembly and after any modification or repair, metallic
LP-gas piping and hose shall be pressure-tested as follows:
a. Piping systems having operating pressures
greater than 20 psig shall be pressure-tested in accordance with the following:
(1) Prior to acceptance and initial
operation, all piping installations shall be visually inspected and
pressure-tested to determine that the materials, design, fabrication, and
installation practices comply with the requirements of this chapter.
(2) Inspection shall consist of visual
examination, during or after manufacture, fabrication, assembly, or pressure
tests as appropriate.
(3) When
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.
(4) When new branches are installed to a new
appliance or appliances, only the newly installed branch or 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.
(5) A piping system shall be tested as a
complete unit or in sections. A valve in a line shall not be used as a bulkhead
between gas in one section of the piping system and test medium in an adjacent
section, unless a double block and bleed valve is installed. 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 applied during the test.
(6) 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.
(7) Prior to testing
the system, the interior of the pipe shall be cleared of all foreign
material.
(8) The test medium shall
be air, nitrogen, carbon dioxide, or an inert gas. Oxygen shall not be
used.
(9) 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 five times the test
pressure.
(10) The test pressure to
be used shall be no less than 50 psi and shall not exceed 75 psi.
(11) Expansion joints shall be provided with
temporary restraints, if required, for the additional thrust load under
test.
(12) 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.
(13) 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 outlet(s).
(14) Where
the piping system is connected to appliances or equipment designed for
operating pressures equal to or greater than the test pressure, such appliances
or equipment shall be isolated from the piping system by closing the individual
appliance or equipment shutoff valve(s).
(15) All testing of piping systems shall be
performed in a manner that protects the safety of employees and the public
during the test.
(16) Test duration
shall be not less than one-half hour for each 500
ft3(14 m3) of pipe volume
or fraction thereof. The duration of the test shall not be required to exceed
24 hours.
EXCEPTION: When a system having a volume of less than 10
ft3(0.28 m3) is tested,
the test duration shall be a minimum of 10 minutes.
b. Piping systems having operating
pressures of 20 psig or less, all polyethylene and polyamide piping, and piping
to which NFPA 54 National Fuel Gas Code, 2015 edition, is applicable shall be
tested in accordance with that code.