C404.6
Insulation of piping. Piping from a water heater to the
termination of the heated water fixture supply pipe shall be insulated in
accordance with Table C403.10.3. On both the inlet and outlet piping of a
storage water heater or heated water storage tank, the piping to a heat trap or
the first 8 feet (2438 mm) of piping, whichever is less, shall be insulated.
Piping that is heat traced shall be insulated in accordance with Table
C403.10.3 or the heat trace manufacturer's instructions. Tubular pipe
insulation shall be installed in accordance with the insulation manufacturer's
instructions. Pipe insulation shall be continuous, including through hangers
and supports, such that thermal bridging is prevented, except where the piping
passes through a framing member. The minimum insulation thickness requirements
of this section shall not supersede any greater insulation thickness
requirements necessary for the protection of piping from freezing temperatures
or the protection of personnel against external surface temperatures on the
insulation.
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EXCEPTION:
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Tubular pipe insulation shall not be required on the
following:
1. The tubing from the connection at the termination of
the fixture supply piping to a plumbing fixture or plumbing appliance.
2. Valves, pumps, strainers and threaded unions in
piping that is 1 inch (25 mm) or less in nominal diameter.
3. Piping from user-controlled shower and bath mixing
valves to the water outlets.
4. Cold-water piping of a demand recirculation water
system.
5. Tubing from a hot drinking-water heating unit to the
water outlet.
6. Piping at locations where a vertical support of the
piping is installed.
7. Piping surrounded by building insulation with a
thermal resistance (R-value) of not less than R-3.
8. Hot water piping that is part of the final pipe run
to the plumbing fixture and is not part of the heated-water circulation system
circulation path is not required to meet the minimum insulation requirements of
Section C404.6.
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C404.6.1
Storage tank insulation. Unfired storage tanks used to store
service hot water at temperatures above 130°F (54°C) shall be wrapped
with an insulating product, installed in accordance with the insulation
manufacturer's instructions and providing a minimum of R-2 additional
insulation for every 10°F (5°C) increase in stored water temperature
above 130°F (54°C). Such additional insulation is also permitted to be
integral to the tank. The insulation is permitted to be discontinuous at
structural supports.
Notes
Wash. Admin. Code §
51-11C-40406
Amended by
WSR
16-03-072, Filed 1/19/2016, effective
7/1/2016
Amended by
WSR
19-02-089, Filed 1/2/2019, effective
7/1/2019
Amended by
WSR
19-24-040, Filed 11/26/2019, effective
7/1/2020
Amended by
WSR
20-21-080, Filed 10/19/2020, effective
2/1/2021
Amended by
WSR
22-14-091, Filed 7/1/2022, effective
7/1/2023
Statutory Authority:
RCW
19.27A.020,
19.27A.025 and
chapters
19.27 and
34.05 RCW. 13-04-056, §
51-11C-40406, filed 2/1/13, effective
7/1/13.
