Page 112 - 2018_IMC

CHAPTER 10

BOILERS, WATER HEATERS
AND PRESSURE VESSELS

User note:
About this chapter: Chapter 10 addresses boilers, water heaters, expansion tanks and pressure vessels in general, such as compressed air
vessels. This chapter includes requirements for components of hydronic HVAC systems, with the focus being on safety, maintenance, testing
and safety control devices.

SECTION 1001 1002.2.1 Sizing. Water heaters utilized for both potable
GENERAL water heating and space-heating applications shall be sized
to prevent the space-heating load from diminishing the
1001.1 Scope. This chapter shall govern the installation,
alteration and repair of boilers, water heaters and pressure required potable water-heating capacity.
vessels. 1002.2.2 Temperature limitation. Where a combination
Exceptions: potable water-heating and space-heating system requires
water for space heating at temperatures higher than 140ºF
1. Pressure vessels used for unheated water supply.
(60ºC), a temperature-actuated mixing valve that conforms
2. Portable unfired pressure vessels and Interstate to ASSE 1017 shall be provided to temper the water sup-
Commerce Commission containers. plied to the potable hot water distribution system to a tem-
3. Containers for bulk oxygen and medical gas. perature of 140ºF (60ºC) or less.
4. Unfired pressure vessels having a volume of 5 cubic 1002.3 Supplemental water-heating devices. Potable water-
3
feet (0.14 m ) or less operating at pressures not heating devices that utilize refrigerant-to-water heat exchang-
exceeding 250 pounds per square inch (psi) (1724 ers shall be approved and installed in accordance with the
kPa) and located within occupancies of Groups B, F, International Plumbing Code and the manufacturer’s instruc-
H, M, R, S and U. tions.
5. Pressure vessels used in refrigeration systems that
are regulated by Chapter 11 of this code. SECTION 1003
6. Pressure tanks used in conjunction with coaxial PRESSURE VESSELS
cables, telephone cables, power cables and other
similar humidity control systems. 1003.1 General. All pressure vessels, unless otherwise
approved, shall be constructed and certified in accordance
7. Any boiler or pressure vessel subject to inspection with the ASME Boiler and Pressure Vessel Code, and shall
by federal or state inspectors. be installed in accordance with the manufacturer’s instruc-
tions and nationally recognized standards. Directly fired pres-
SECTION 1002 sure vessels shall meet the requirements of Section 1004.
WATER HEATERS 1003.2 Piping. All piping materials, fittings, joints, connec-
1002.1 General. Potable water heaters and hot water storage tions and devices associated with systems utilized in conjunc-
tanks shall be listed and labeled and installed in accordance tion with pressure vessels shall be designed for the specific
with the manufacturer’s instructions, the International application and shall be approved.
Plumbing Code and this code. Water heaters shall be capable 1003.3 Welding. Welding on pressure vessels shall be per-
of being removed without first removing a permanent portion formed by an R-Stamp holder in accordance with the
of the building structure. The potable water connections and National Board Inspection Code, Part 3 or in accordance
relief valves for all water heaters shall conform to the require- with an approved standard.
ments of the International Plumbing Code. Domestic electric
water heaters shall comply with UL 174 or UL 1453. Com-
mercial electric water heaters shall comply with UL 1453. SECTION 1004
Oil-fired water heaters shall comply with UL 732. Solid- BOILERS
fuel-fired water heaters shall comply with UL 2523. Solar 1004.1 Standards. Boilers shall be designed, constructed and
thermal water heating systems shall comply with Chapter 14 certified in accordance with the ASME Boiler and Pressure
and ICC 900/SRCC 300. Vessel Code, Section I or IV. Controls and safety devices for
1002.2 Water heaters utilized for space heating. Water boilers with fuel input ratings of 12,500,000 Btu/hr
heaters utilized both to supply potable hot water and provide (3,662,500 W) or less shall meet the requirements of ASME
hot water for space-heating applications shall be listed and CSD-1. Controls and safety devices for boilers with inputs
labeled for such applications by the manufacturer and shall greater than 12,500,000 Btu/hr (3,662,500 W) shall meet the
be installed in accordance with the manufacturer’s instruc- requirements of NFPA 85. Packaged oil-fired boilers shall be
tions and the International Plumbing Code. listed and labeled in accordance with UL 726. Packaged elec-

2018 INTERNATIONAL MECHANICAL CODE  95
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