Regulations last checked for updates: May 04, 2025

Title 46 - Shipping last revised: Mar 17, 2025
§ 52.01-50 - Fusible plugs (modifies A-19 through A-21).

(a) Fusible plugs must comply with the requirements of A19 and A20 of Section I of the ASME BPVC (incorporated by reference; see § 52.01-1) and be stamped on the casing with the name of the manufacturer, and on the water end of the fusible metal “ASME Std.” Fusible plugs are not permitted where the maximum steam temperature to which they are exposed exceeds 218 °C (425 °F).

(b)(1) Fusible plugs must be cleaned and will be examined by the marine inspector at each inspection for certification, periodic inspection, or if the boiler is opened for repair or inspection. If in the marine inspector's opinion, the condition of any plug is satisfactory, it may be continued in use.

(2) When fusible plugs are renewed at other than the inspection for certification and no marine inspector is in attendance, the Chief Engineer must report the renewal to the Officer in Charge, Marine Inspection. This report must contain the following information:

(i) Name and official number of vessel.

(ii) Date of renewal of fusible plugs.

(iii) Number and location of fusible plugs renewed in each boiler.

(iv) Manufacturer and rating of each plug.

(v) Reason for renewal.

[CGFR 68-82, 33 FR 18815, Dec. 18, 1968, as amended by CGD 81-79, 50 FR 9432, Mar. 8, 1985; USCG-1999-4976, 65 FR 6500, Feb. 9, 2000; USCG-2003-16630, 73 FR 65160, Oct. 31, 2008]
authority: 46 U.S.C. 3306,3307,3703; E.O. 12234, 45 FR 58801, 3 CFR, 1980 Comp., p. 277; Department of Homeland Security Delegation No. 00170.1, Revision No. 01.3
source: CGFR 68-82, 33 FR 18815, Dec. 18, 1968, as amended by USCG-2020-0634, 89 FR 50095, June 12, 2024, unless otherwise noted.
cite as: 46 CFR 52.01-50