Certain material is incorporated by reference into this part with the approval of the Director of the Federal Register under 5 U.S.C. 552(a) and 1 CFR part 51. To enforce any edition other than that specified in this section, the Coast Guard must publish a document in the Federal Register and the material must be available to the public. All approved incorporation by reference (IBR) material is available for inspection at the U.S. Coast Guard and the National Archives and Records Administration (NARA). Contact U.S. Coast Guard Headquarters at: Commandant (CG-ENG), Attn: Office of Design and Engineering Standards, U.S. Coast Guard Stop 7509, 2703 Martin Luther King Jr. Avenue SE, Washington, DC 20593-7509; phone (202) 372-1375; email [email protected]. For information on the availability of this material at NARA, visit www.archives.gov/federal-register/cfr/ibr-locations or email [email protected]. The material may be obtained from the following sources:

(a) American Society of Mechanical Engineers (ASME), Two Park Avenue, New York, NY 10016-5990; 800-843-2763; [email protected]; www.asme.org.

(1) ASME BPVC.I-2019, 2019 ASME Boiler and Pressure Vessel Code, Section I, Rules for Construction of Power Boilers, 2019 Edition, issued July 1, 2019 (“Section I of the ASME BPVC”); IBR approved for § 53.01-10(e).

(2) ASME BPVC.IV-2019, 2019 ASME Boiler and Pressure Vessel Code, Section IV, Rules for Construction of Heating Boilers, 2019 Edition, issued July 1, 2019 (“Section IV of the ASME BPVC”); IBR approved for §§ 53.01-3; 53.01-5; 53.01-10(a); 53.05-1(a); 53.05-2(a); 53.05-3; 53.05-5; 53.10-1; 53.10-3(a); 53.10-10; 53.10-15; 53.12-1(a).

(b) UL Solutions, 333 Pfingston Road, Northbrook, IL 60062; 847-272-8800; www.ul.com.

(1) UL 174, Standard for Safety, Household Electric Storage Tank Water Heaters, Eleventh Edition, dated April 29, 2004, including revisions through December 15, 2016 (“UL 174”); IBR approved for § 53.01-10(c).

(2) UL 1453, Standard for Safety, Electric Booster and Commercial Storage Tank Water Heaters, Sixth Edition, dated March 29, 2016, including revisions through March 9, 2017 (“UL 1453”); IBR approved for § 53.01-10(c).

(a) Heating boilers must be designed, constructed, inspected, tested, and stamped in accordance with Section IV of the ASME BPVC (incorporated by reference; see § 53.01-1) as limited, modified, or replaced by specific requirements in this part. The provisions in the appendices to Section IV of the ASME BPVC are adopted and must be followed when the requirements in Section IV make them mandatory. For general information, table 1 to § 53.01-3(a) lists the various paragraphs in Section IV of the ASME BPVC that are limited, modified, or replaced by regulations in this part.

(b) References to the ASME BPVC, such as paragraph HG-307, indicate:

(1) H = Section IV of the ASME BPVC.

(2) G = Part containing general requirements.

(3) 3 = Article in part.

(4) 307 = Paragraph within Article 3.

(c) When a paragraph or a section of the regulations in this part relates to Section IV of the ASME BPVC, the relationship with the code will be shown immediately following the heading of the section or at the beginning of the paragraph, as follows:

(1) (Modifies H__.) This indicates that the material in H__ is generally applicable but is being altered, amplified, or augmented.

(2) (Replaces H__.) This indicates that H__ does not apply.

(3) (Reproduces H__.) This indicates that H__ is being identically reproduced for convenience, not for emphasis.

(a) The regulations in this part apply to steam heating boilers, hot water boilers (which include hot water heating boilers and hot water supply boilers), and to appurtenances thereto. The requirements in this part must be used in conjunction with Section IV of the ASME BPVC (incorporated by reference; see § 53.01-1). Table 1 to § 54.01-5 of this subchapter gives a breakdown by parts in this subchapter of the regulations governing various types of pressure vessels and boilers.

(b) (Modifies HG-100.) The requirements of part HG of Section IV of the ASME BPVC must be used except as noted otherwise in this part.

(a) General. The service restrictions and exceptions must be as indicated in this section in lieu of the requirements of HG-101 of Section IV of the ASME BPVC (incorporated by reference; see § 53.01-1).

(b) Service restrictions. (1) Boilers of wrought materials must be restricted to a maximum of 103 kPa gage (15 psig) for steam and a maximum of 689 kPa (100 psig) or 121 °C (250 °F) for hot water. If operating conditions exceed these limits, design and fabrications must be in accordance with part 52 of this subchapter.

(2) Boilers of cast iron materials must be restricted to a maximum of 103 kPa gage (15 psig) for steam and to a maximum of 206 kPa gage (30 psig) or 121 °C (250 °F) for hot water.

(c) Hot water supply boilers. (1) Electrically fired hot water supply boilers that have a capacity not greater than 454 liters (120 gallons), a heat input not greater than 58.6 kilowatts (200,000 Btu per hour), and are listed as approved under UL 174 or UL 1453 (both incorporated by reference; see § 53.01-1) are exempted from the requirements of this part provided they are protected by a pressure relief device. This relief device need not comply with § 53.05-2.

(2) Oil fired hot water supply boilers are not exempted from the requirements of this part on the basis of size or heat input.

(d) Exhaust gas boilers. Exhaust gas type boilers must be restricted to a working pressure equal to or less than 103 kPa gage (15 psig) and an operating temperature equal to or less than 454 °C (850 °F). The design temperature of parts exposed to the exhaust gas must be the maximum temperature that could normally be produced by the source of exhaust gas. This temperature must be verified by testing or by the manufacturer of the engine or other equipment producing the exhaust.

(e) ASME BPVC Section I. Heating boilers whose operating conditions are within the service restrictions of paragraph (b)(1) of this section may be constructed in accordance with Section I of the ASME BPVC (incorporated by reference; see § 53.01-1). In addition, these heating boilers must:

(1) Be stamped with the appropriate ASME symbol in accordance with Section I of the ASME BPVC;

(2) Meet the service restrictions of paragraph (b)(2) of this section if made of cast iron;

(3) Have safety valves which meet the requirements of § 52.01-120 of this subchapter;

(4) If a hot water supply boiler, have a temperature relief valve or a pressure-temperature relief valve in accordance with § 53.05-2(c);

(5) If automatically controlled, meet the applicable requirements in part 63 of this subchapter; and

(6) Meet the inspection and test requirements of § 53.10-3.

(f) Controls and miscellaneous accessories. Refer to part 63 of this subchapter for the requirements governing controls and miscellaneous accessories.