Rules for this Code Section have been developed considering the
needs for applications that include piping typically found in
electric power generating stations, in industrial and institutional
plants, geothermal heating systems, and central and district
heating and cooling systems.
This Code prescribes requirements for the design, materials,
fabrication, erection, test, inspection, operation, and maintenance
of piping systems.
Piping as used in this Code includes pipe, flanges, bolting,
gaskets, valves, pressure-relieving valves/ devices, fittings, and
the pressure containing portions of other piping components,
whether manufactured in accordance with Standards listed in Table
126.1 or specially designed. It also includes hangers and supports
and other equipment items necessary to prevent overstressing the
pressure containing components.
Rules governing piping for miscellaneous appurtenances, such as
water columns, remote water level indicators, pressure gages, gage
glasses, etc., are included within the scope of this Code, but the
requirements for boiler appurtenances shall be in accordance with
Section I of the ASME Boiler and Pressure Vessel Code, PG-60.
The users of this Code are advised that in some areas
legislation may establish governmental jurisdiction over the
subject matter covered by this Code. However, any such legal
requirement shall not relieve the owner of his inspection
responsibilities specified in para. 136.1.
Power piping systems as covered by this Code apply to all piping
and their component parts except as excluded in para. 100.1.3. They
include but are not limited to steam, water, oil, gas, and air
(A) This Code covers boiler external piping as defined
below for power boilers and high temperature, high pressure water
boilers in which steam or vapor is generated at a pressure of more
than 15 psig [100 kPa (gage)]; and high temperature water is
generated at pressures exceeding 160 psig [1 103 kPa (gage)] and/or
temperatures exceeding 250°F (120°C).
Boiler external piping shall be considered as piping that begins
where the boiler proper terminates at
(1) the first circumferential joint for welding end
(2) the face of the first flange in bolted flanged
(3) the first threaded joint in that type of
connection; and that extends up to and including the valve or
valves required by para. 122.1.
The terminal points themselves are considered part of the boiler
external piping. The terminal points and piping external to power
boilers are illustrated by Figs. 100.1.2(A.1), 100.1.2(A.2),
100.1.2(B), and 100.1.2(C).
Piping between the terminal points and the valve or valves
required by para. 122.1 shall be provided with Data Reports,
inspection, and stamping as required by Section I of the ASME
Boiler and Pressure Vessel Code. All welding and brazing of this
piping shall be performed by manufacturers or contractors
authorized to use the appropriate symbol shown in Figs. PG-105.1
through PG-105.3 of Section I of the ASME Boiler and Pressure
Vessel Code. The installation of boiler external piping by
mechanical means may be performed by an organization not holding a
Code symbol stamp. However, the holder of a valid S, A, or PP
Certificate of Authorization shall be responsible for the
documentation and hydrostatic test, regardless of the method of
assembly. The quality control system requirements of Section I of
the ASME Boiler and Pressure Vessel Code shall apply.