49 CFR § 179.200-4 - Insulation.

---
identifier: "/us/cfr/t49/s179.200-4"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "49 CFR § 179.200-4 - Insulation."
title_number: 49
title_name: "Transportation"
section_number: "179.200-4"
section_name: "Insulation."
chapter_name: "PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
subchapter_number: "C"
subchapter_name: "HAZARDOUS MATERIALS REGULATIONS"
part_number: "179"
part_name: "SPECIFICATIONS FOR TANK CARS"
positive_law: false
currency: "2026-03-24"
last_updated: "2026-03-24"
format_version: "1.1.0"
generator: "[email protected]"
authority: "49 U.S.C. 5101-5128; 49 CFR 1.81 and 1.97."
regulatory_source: "29 FR 18995, Dec. 29, 1964, unless otherwise noted. Redesignated at 32 FR 5606, Apr. 5, 1967."
cfr_part: "179"
---


# 179.200-4 Insulation.

(a) If insulation is applied, the tank shell and expansion dome when used must be insulated with an approved material. The entire insulation must be covered with a metal jacket of a thickness not less than 11 gauge (0.1196 inch) nominal (Manufacturer's Standard Gauge) and flashed around all openings so as to be weather tight. The exterior surface of a carbon steel tank and the inside surface of a carbon steel jacket must be given a protection coating.

(b) If insulation is a specification requirement, it shall be of sufficient thickness so that the thermal conductance at 60 °F is not more than 0.225 Btu per hour, per square foot, per degree F temperature differential, unless otherwise provided in § 179.201-1. If exterior heaters are attached to tank, the thickness of the insulation over each heater element may be reduced to one-half that required for the shell.

[29 FR 18995, Dec. 29, 1964. Redesignated at 32 FR 5606, Apr. 5, 1967, and amended by Amdt. 179-10, 36 FR 21349, Nov. 6, 1971; Amdt. 179-50, 60 FR 49078, Sept. 21, 1995]