Minnesota Administrative Rules
Agency 151 - Labor and Industry Department
Chapter 1346 - MINNESOTA MECHANICAL AND FUEL GAS CODES
MINNESOTA MECHANICAL CODE
Part 1346.1204 - SECTION 1204 PIPE INSULATION
Universal Citation: MN Rules 1346.1204
Current through Register Vol. 49, No. 13, September 23, 2024
IMC Section 1204.2 is amended to read as follows:
1204.2 Required thickness. Hydronic, steam, and condensate piping shall be insulated in accordance with this section.
Exceptions: Piping insulation is not required for:
1. Piping installed within HVAC
equipment; or
2. Piping installed
in basements, crawl spaces, and cellars.
Insulation Thickness for Nominal Pipe Diameters
| Fluid Temperature Range oF | Runouts (see item C) | 1 inch (25.4 mm) and Less | 1.25 to 2" (31.7 to 50.8 mm) | 2.5 to 4" (63.5 to 101.6 mm) | 5 to 6" (127 to 152 mm) | 8" (203 mm) and Larger |
| Piping System Type - Heating | ||||||
| Above 350 | 1.5 | 2.5 | 2.5 | 3.0 | 3.5 | 3.5 |
| 251-350 | 1.5 | 2.0 | 2.5 | 2.5 | 3.5 | 3.5 |
| 201-250 | 1.0 | 1.5 | 1.5 | 2.0 | 2.0 | 3.5 |
| 141-200 | 0.5 | 1.5 | 1.5 | 1.5 | 1.5 | 1.5 |
| 105-140 | 0.5 | 1.0 | 1.0 | 1.0 | 1.5 | 1.5 |
| Piping System Type - Cooling | ||||||
| 40-55 | 0.5 | 0.5 | 0.75 | 1 | 1 | 1 |
| Below 40 (see item D) | 1 | 1 | 1.5 | 1.5 | 1.5 | 1.5 |
A. Insulation
thickness in this section assumes a k-value of 0.27. If the k-value of a
product is less than 0.22, then the thickness must be adjusted to have an
equivalent R-value.
B. For piping exposed to outdoor air,
insulation thickness must be 0.5 inch (12.7 mm) greater than required in the
table.
C. This column applies only
to runouts (branches) 2 inches (50.8 mm) in diameter and less, not exceeding 12
feet (3658 mm) in length, to individual terminal units. All other runouts shall
meet the requirements given in other columns in the table, as
appropriate.
D. For applications
with fluid temperatures of 32
oF (0
oC) and below, a vapor retarder shall be
installed in accordance with IMC Section
604.11.
Statutory Authority: MS s 16B.59; 16B.61; 16B.64; 326B.101; 326B.106; 326B.13
Disclaimer: These regulations may not be the most recent version. Minnesota may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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