Coverage and Application. This Code Section has
rules for the piping in industrial, institutional, commercial, and
public buildings, and multi-unit residences, which does not require
the range of sizes, pressures, and temperatures covered in B31.1.
This Code prescribes requirements for the design, materials,
fabrication, installation, inspection, examination, and testing of
piping systems for building services. It includes piping systems in
the building or within the property limits.
Services and Limits
(a) Services. This Code applies to the following
building services, except as excluded in para. 900.1.3:
(1) water and antifreeze solutions for heating and
(2) condensing water
(3) steam or other condensate
(4) other nontoxic liquids
(7) compressed air
(8) other nontoxic, nonflammable gases
(9) combustible liquids including fuel oil
(b) Boiler External Piping. The scope of this
Code includes boiler external piping within the following
(1) for steam boilers, 15 psig (103 kPa gage) max.
(2) for water heating units, 160 psig (1 103 kPa gage)
max. and 250°F (121°C) max.
Boiler external piping above these pressure or temperature
limits is within the scope of ASME B31.1. Boiler external piping is
the piping connected to the boiler and extending to the points
identified in Fig. 900.1.2.
(c) Material and Size Limits. Piping systems of the
following materials are within the scope of this Code, through the
indicated maximum size (andwall thickness if noted):
(1) carbon steel: NPS 48 (DN 1 200) and 0.50 in. (12.7
(2) stainless steel: NPS 24 (DN 600) and 0.50 in. (12.7
(3) aluminum: NPS 12 (DN 300)
(4) brass and copper: NPS 12 (DN 300) and 12.125 in.
(308 mm) O.D. for copper tubing
(5) thermoplastics: NPS 24 (DN 600)
(6) ductile iron: NPS 48 (DN 1 200)
(7) reinforced thermosetting resin: 24 in. (600 mm)
Other materials may be used as noted in Chapter III.
(d) Pressure Limits. Piping systems with working
pressures not in excess of the following limits are within the
scope of this Code:
(1) steam and condensate: 150 psig (1 034 kPa g)
(2) liquids: 350 psig (2 413 kPa g)
(3) vacuum: 1 atm external pressure
(4) compressed air and gas: 150 psig (1 034 kPa g)
(e) Temperature Limits. Piping systems with
working temperatures not in excess of the following limits are
within the scope of this Code:
(1) steam and condensate: 366°F (186°C)
(2) other gases and vapors: 200°F (93°C)
(3) other nonflammable liquids: 250°F (121°C)
The minimum temperature for all services is 0°F (−18°C).
Exclusions. This Code does not apply to
economizers, heaters, pumps, tanks, heat exchangers, and equipment
covered by the ASME Boiler and Pressure Vessel (BPV) Code.