CFR > Title 46 - Shipping > CHAPTER I—COAST GUARD, DEPARTMENT OF HOMELAND SECURITY > SUBCHAPTER D—TANK VESSELS (parts 30 to 39) > PART 39—VAPOR CONTROL SYSTEMS > SUBPART 39.20—Design and Equipment (§39.20-1 to §39.20-13) > 39.20-1—Vapor collection system—TB/ALL.

39.20-1—Vapor collection system—TB/ALL.

(a) Each vapor collection system must meet the following requirements:
(1) Except as allowed by paragraph (a)(3) of this section or the Commandant (CG-522), vapor collection piping must be permanently installed, with the vessel's vapor connection located as close as practical to the loading manifold;
(2) If the vessel collects vapors from incompatible cargoes simultaneously, it must keep the incompatible vapors separate throughout the entire vapor collection system;
(3) A vessel certified to carry cargo listed in Table 151.05 of part 151 or Table 1 of part 153 of this chapter may have vapor connections located in the vicinity of each tank in order to preserve segregation of cargo systems, in lieu of common header piping;
(4) A means must be provided to eliminate liquid condensate which may collect in the system, such as draining and collecting liquid from each low point in the line;
(5) Vapor collection piping must be electrically bonded to the hull and must be electrically continuous; and
(6) An inerted tankship must have a means to isolate the inert gas supply from the vapor collection system. The inert gas main isolation valve required by SOLAS 74, as amended, chapter II-2, Regulation 62.10.8 may be used to satisfy this requirement.
(b) The vapor collection system must not interfere with the proper operation of the cargo tank venting system.
(c) An isolation valve capable of manual operation must be provided at the vessel vapor connection. The valve must have an indicator to show clearly whether the valve is in the open or closed position, unless the valve position can be readily determined from the valve handle or valve stem.
(d) The last 1.0 meter (3.3 feet) of vapor piping before the vessel vapor connection must be:
(1) Painted red/yellow/red with:
(i) The red bands 0.1 meter (0.33 feet) wide, and
(ii) The middle yellow band 0.8 meter (2.64 feet) wide; and
(2) Labeled “VAPOR” in black letters at least 50 millimeters (2 inches) high.
(e) Each vessel vapor connection flange must have a permanently attached 0.5 inch diameter stud at least 1.0 inch long projecting outward from the flange face. The stud must be located at the top of the flange, midway between bolt holes, and in line with the bolt hole pattern.
(f) Each hose used for transferring vapors must:
(1) Have a design burst pressure of at least 25 psig;
(2) Have a maximum allowable working pressure of at least 5 psig;
(3) Be capable of withstanding at least 2.0 psi vacuum without collapsing or constricting;
(4) Be electrically continuous with a maximum resistance of ten thousand (10,000) ohms;
(5) Have flanges with:
(i) A bolt hole arrangement complying with the requirements for 150 pound class ANSI B16.5 flanges, and
(ii) One or more 0.625 inch diameter holes in the flange located midway between bolt holes and in line with the bolt hole pattern;
(6) Be abrasion resistant and resistant to kinking; and
(7) Have the last 1.0 meter (3.3 feet) of each end of the vapor hose marked in accordance with paragraph (d) of this section.
(g) Vapor hose handling equipment must be provided with hose saddles which provide adequate support to prevent kinking or collapse of hoses.
[CGD 88-102, 55 FR 25446, June 21, 1990, as amended by CGD 95-072, 60 FR 50462, Sept. 29, 1995; CGD 96-041, 61 FR 50727, Sept. 27, 1996]