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(continued)
(b)(1) All vessels having oil fired boilers must have at least two fuel service pumps, each of sufficient capacity to supply all the boilers at full power, and arranged so that one may be overhauled while the other is in service. At least two fuel oil heaters of approximately equal capacity must be installed and so arranged that any heater may be overhauled while the other(s) is (are) in service. Suction and discharge strainers must be of the duplex or other type capable of being cleaned without interrupting the oil supply.
(2) All auxiliary boilers, except those furnishing steam for vital equipment and fire extinguishing purposes other than duplicate installations, may be equipped with a single fuel oil service pump and a single fuel oil heater. Such pumps need not be fitted with discharge strainers.
(3) Strainers must be located so as to preclude the possibility of spraying oil on the burner or boiler casing, or be provided with spray shields. Coamings, drip pans, etc., must be fitted under fuel oil service pumps, heaters, etc., where necessary to prevent oil drainage to the bilge.
(4) Boilers burning fuel oils of low viscosity need not be equipped with fuel oil heaters, provided acceptable evidence is furnished to indicate that satisfactory combustion will be obtained without the use of heaters.
(c) Piping between service pumps and burners shall be located so as to be readily observable, and all bolted flange joints shall be provided with a wrap around deflector to deflect spray in case of a leak. The relief valve located at the pump and the relief valves fitted to the fuel oil heaters shall discharge back into the settling tank or the suction side of the pump. The return line from the burners shall be so arranged that the suction piping cannot be subjected to discharge pressure.
(d) If threaded-bonnet valves are employed, they shall be of the union-bonnet type capable of being packed under pressure.
(e) Unions shall not be used for pipe diameters of 1 inch and above.
(f) Boiler header valves of the quick closing type shall be installed in the fuel supply lines as close to the boiler front header as practicable. The location is to be accessible to the operator or remotely controlled.
(g) Bushings and street ells are not permitted in fuel oil discharge piping.
(h) Each fuel-oil service pump must be equipped with controls as required by §58.0125 of this subchapter.
[CGFR 6882, 33 FR 18843, Dec. 18, 1968, as amended by CGFR 69127, 35 FR 9978, June 17, 1970; CGD 77140, 54 FR 40609, Oct. 2, 1989; CGD 83043, 60 FR 24774, May 10, 1995]
§ 56.50-70 Gasoline fuel systems.
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(a) Material. (1) Fuel supply piping to the engines shall be of seamless drawn annealed copper pipe or tubing, nickel copper, or copper nickel pipe or tubing meeting the requirements of subpart 56.60.
(2) Tubing wall thicknesses shall not be less than the larger of that shown in Table 56.5070(a), or as required by §56.0710(e) and 104.1.2 of ANSI-B31.1.
(3) Tubing fittings shall be of nonferrous drawn or forged metal and of the flared type except that the flareless fittings of the nonbite type may be used when the tubing system is of nickel copper or copper nickel. Tubing shall be cut square and flared by suitable tools. Tube ends shall be annealed before flaring. Pipe fittings shall be of nonferrous material. Pipe thread joints shall be made tight with a suitable compound.
(4) Valves for fuel lines shall be of nonferrous material of the union bonnet type with ground seats except that cocks may be used if they are the solid bottom type with tapered plugs and union bonnets.
Table 56.50-70(a)_Tubing Wall Thickness
------------------------------------------------------------------------
Thickness
Outside diameter of tubing in inches ---------------------
B.W.G. Inch
------------------------------------------------------------------------
\1/8\, \3/16\, \1/4\.............................. #21 0.032
\5/16\, \3/8\..................................... #20 .035
\7/16\, \1/2\..................................... #19 .042
------------------------------------------------------------------------
(b) Installation. (1) All fuel pipes, pipe connections, and accessories shall be readily accessible. The piping shall run in sight wherever practicable, protected against mechanical injury, and effectively secured against excessive movement and vibration by the use of soft nonferrous metal liners or straps without sharp edges. Where passing through steel decks or bulkheads, fuel lines shall be protected by close fitting ferrules or stuffing boxes. Refer to §56.3025 for tubing joint installations.
(2) A short length of suitable metallic or nonmetallic flexible tubing or hose, or a loop of annealed copper tubing shall be installed in the fuel supply line at or near the engine to prevent damage by vibration. If nonmetallic flexible hose is used it shall meet the requirements of §56.6025(b) for fuel service. Flexible hose connections should maintain metallic contact between the sections of the fuel supply lines; however, if such contact is not maintained, the fuel tank shall be grounded.
(3) Valves in fuel lines shall be installed to close against the flow.
(c) Shutoff valves. Shutoff valves of a suitable type shall be installed in the fuel supply lines, one as close to each tank as practicable, and one as close to each carburetor as practicable. Where fuel tanks are installed below the weather deck, arrangements shall be provided for operating all shutoff valves at the tanks from outside the compartments in which they are located, preferably from an accessible position on the weather deck. The operating gear for the shutoff valves at the tanks shall be accessible at all times and shall be suitably marked.
(d) Strainers. A suitable twin strainer shall be fitted in the fuel supply line in the engine compartment. Strainers shall be of the type opening on top for cleaning screens. A drip pan shall be fitted under the strainer.
(e) Outlets and drains. Outlets in fuel lines for drawing gasoline for any purpose are prohibited. Valved openings in the bottom of fuel tanks are prohibited; however, openings fitted with threaded plug or cap can be used for cleaning purposes.
(f) Fuel suction connections. All fuel suction and return lines shall enter the top of the fuel tanks and connections shall be fitted into spuds. Such lines shall extend nearly to the bottom of the tank.
(g) Filling and sounding pipes. Filling and sounding pipes shall be so arranged that vapors or possible overflow when filling cannot escape to the inside of the vessel but will discharge overboard. Such pipes shall terminate on the weather deck clear of any coamings and shall be fitted with suitable shutoff valves or deck plugs. Filling and sounding pipes shall extend to within one-half of their diameter from the bottom of the tank or from the surface of the striking plate in case of a sounding pipe. A flame screen of noncorrodible wire mesh shall be fitted in the throat of the filling pipe. Sounding pipes shall be kept closed at all times except during sounding.
(h) Vent pipes. Each tank shall be fitted with a vent, the cross-sectional area of which shall not be less than that of the filling pipe. The vent pipes shall terminate at least 2 feet above the weather deck and not less than 3 feet from any opening into living quarters or other below deck space. The ends of vent pipes shall terminate with U-bends and shall be fitted with flame screens or flame arresters. The flame screens shall consist of a single screen of corrosion resistant wire of at least 30 by 30 mesh.
(i) Gasoline tanks. For requirements pertaining to independent gasoline fuel tanks see subpart 58.50 of this subchapter.
(j) Fuel pumps. Each fuel pump must be equipped with controls as required by §58.0125 of this subchapter.
[CGFR 6882, 33 FR 18843, Dec. 18, 1968, as amended by CGFR 69127, 35 FR 9978, June 17, 1970; CGFR 7259R, 37 FR 6189, Mar. 25, 1972; CGD 83043, 60 FR 24774, May 10, 1995; USCG200213058, 67 FR 61278, Sept. 30, 2002]
§ 56.50-75 Diesel fuel systems.
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(a) Vessels greater than 100 gross tons. (1) The diesel fuel system shall comply with §§56.5060, 56.5085, and 56.5090. The fuel supply piping to engines shall be of seamless steel, annealed seamless copper or brass pipe or tubing, or of nickel copper or copper nickel alloy meeting the requirements of subpart 56.60 for materials and §56.5070(a)(2) for thickness. Fuel oil service or unit pumps shall be equipped with controls to comply with §58.0125 of this subchapter.
(2) The installation shall comply with §56.5070(b).
(3) Tubing connections and fittings shall be drawn or forged metal of the flared type except that flareless fittings of the nonbite type may be used when the tubing system is steel, nickel-copper, or copper-nickel. When making flared tube connections the tubing shall be cut square and flared by suitable tools. Tube ends shall be annealed before flaring.
(b) Vessels of 100 gross tons and less and tank barges. (1) Materials. Fuel supply piping shall be of copper, nickel copper or copper nickel having a minimum wall thickness of 0.035 inch except that piping of other materials such as seamless steel pipe or tubing which provides equivalent safety may be used.
(2) Tubing connections and fittings. Tubing connections shall comply with the provisions of §56.5075(a)(3).
(3) Installation. The installation of diesel fuel piping shall comply with the requirements of §56.5070(b).
(4) Shutoff valves. Shutoff valves shall be installed in the fuel supply lines, one as close to each tank as practicable, and one as close to each fuel pump as practicable. Valves shall be accessible at all times.
(5) Outlets and drains. Valves for removing water or impurities from fuel oil systems will be permitted in the machinery space provided such valves are fitted with caps or plugs to prevent leakage.
(6) Filling pipe. Tank filling pipes on motorboats and motor vessels of less than 100 gross tons and tank barges shall terminate on an open deck and shall be fitted with suitable shutoff valves, deck plugs, or caps.
(7) Vent pipes. Each tank shall be fitted with a vent pipe complying with §56.5085.
(8) Independent diesel fuel tanks. See subpart 58.50 of this subchapter for specific requirements.
[CGFR 6882, 33 FR 18843, Dec. 18, 1968, as amended by CGD 77140, 54 FR 40610, Oct. 2, 1989]
§ 56.50-80 Lubricating-oil systems.
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(a) The lubricating oil system shall be designed to function satisfactorily when the vessel has a permanent 15° list and a permanent 5° trim.
(b) When pressure or gravity-forced lubrication is employed for the steam driven main propelling machinery, an independent auxiliary lubricating pump shall be provided.
(c) Oil coolers on steam driven machinery shall be provided with two separate means of circulating water through the coolers.
(d) For internal combustion engine installations, the requirements of paragraphs (b) and (c) of this section shall be met, but they do not apply to vessels in river and harbor service, nor to any vessel below 300 gross tons. Where the size and design of an engine is such that lubrication before starting is not necessary and an attached pump is normally used, the independent auxiliary pump is not required if a duplicate of the attached pump is carried as spare. In meeting the requirements of paragraph (c) of this section in the case of internal combustion engines, two separate means are to be provided for circulating coolant on those engines on which oil coolers are fitted. One of those means must be independently driven and may consist of a connection from a pump of adequate size normally used for other purposes utilizing the required coolant. Where the design of an engine will not readily accommodate an independent pump connection, the independent auxiliary pump will not be required if a duplicate of the attached pump is carried as a spare. Oil filters shall be provided on all internal combustion engine installations. On main propulsion engines which are fitted with full-flow type filters, the arrangement shall be such that the filters may be cleaned without interrupting the oil supply except that such an arrangement is not required on vessels having more than a single main propulsion engine.
(e) The lubricating oil piping shall be independent of other piping systems and shall be provided with necessary coolers, heaters, filters, etc., for proper operation. Oil heaters shall be fitted with bypasses.
(f) Diesel engine lubrication systems shall be so arranged that vapors from the sump tank may not be discharged back into the engine crank case of engines of the dry sump type.
(g) Steam turbine driven propulsion and auxiliary generating machinery depending on forced lubrication shall be arranged to shut down automatically upon failure of the lubricating system.
(h) Sight-flow glasses may be used in lubricating-oil systems provided it has been demonstrated, to the satisfaction of the Commanding Officer, Marine Safety Center, that they can withstand exposure to a flame at a temperature of 927 °C (1700 °F) for one hour, without failure or appreciable leakage.
(i) Steam driven propulsion machinery must be provided with an emergency supply of lubricating oil that must operate automatically upon failure of the lubricating oil system. The emergency oil supply must be adequate to provide lubrication until the equipment comes to rest during automatic shutdown.
[CGFR 6882, 33 FR 18843, Dec. 18, 1968, as amended by CGFR 69127, 35 FR 9979, June 17, 1970; CGD 81030, 53 FR 17837, May 18, 1988; CGD 83043, 60 FR 24774, May 10, 1995]
§ 56.50-85 Tank-vent piping.
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(a) This section applies to vents for all independent, fixed, non-pressure tanks or containers or for spaces in which liquids, such as fuel, ship's stores, cargo, or ballast, are carried.
(1) The structural arrangement in double bottom and other tanks shall be such as to permit the free passage of air and gases from all parts of the tanks to vent pipes.
(2) Tanks having a comparatively small surface, such as fuel oil settling tanks, need be fitted with only one vent pipe, but tanks having a comparatively large surface shall be fitted with at least two vent pipes. The vents shall be located so as to provide venting of the tanks under any service condition.
(3) Vent pipes for fuel oil tanks shall, wherever possible, have a slope of no less than 30°. Header lines, where both ends are adequately drained to a tank, are excluded from this requirement.
(4) Tank vents must extend above the weather deck, except vents from fresh water tanks, bilge oily-water holding tanks, bilge slop tanks, and tanks containing Grade E combustible liquids, such as lubricating oil, may terminate in the machinery space, provided
(i) The vents are arranged to prevent overflow on machinery, electrical equipment, and hot surfaces;
(ii) Tanks containing combustible liquids are not heated; and
(iii) The vents terminate above the deep load waterline if the tanks have boundaries in common with the hull.
(5) Vents from oil tanks must terminate not less than three feet from any opening into living quarters.
(6) Vents extending above the freeboard deck or superstructure deck from fuel oil and other tanks must be at least Schedule 40 in wall thickness. Except for barges in inland service and for Great Lakes vessels, the height from the deck to any point where water may gain access through the vent to below deck must be at least 30 inches (760mm) on the freeboard deck and 17 1/2 inches (450mm) on the superstructure deck. On Great Lakes vessels, the height from the deck to any point where water may gain access through the vent to below deck must be at least 30 inches (760mm) on the freeboard deck, 24 inches (610mm) on the raised quarterdeck, and 12 inches (305mm) on other superstructure decks. Where the height of vents on Great Lakes vessels may interfere with the working of the vessel, a lower height may be approved by the Marine Safety Center provided the vent cap is properly protected from mechanical damage. For barges in inland service, the vents must extend at least six inches above the deck. A lesser amount may be approved by the Marine Safety Center if evidence is provided that a particular vent has proven satisfactory in service.
(7) Satisfactory means, permanently attached, shall be provided for closing the openings of all vents, except that barges in inland service may be exempted. Acceptable means of closure are:
(i) A ball check valve where the ball float, normally in the open position, will float up and close under the action of a submerging wave. The valve shall be designed so that the effective clear discharge area through the valve with the float in the open position is not less than the inlet area of the vent pipe to which the valve is connected.
(ii) A hinged closure normally open on the outlet of the return bend, which must close automatically by the force of a submerging wave; or
(iii) Another suitable device acceptable to the Commanding Officer, Marine Safety Center.
(8) Vent outlets from all tanks which may emit flammable or combustible vapors, such as bilge slop tanks and contaminated drain tanks, must be fitted with a single screen of corrosion-resistant wire of at least 30 by 30 mesh, or two screens of at least 20 by 20 mesh spaced not less than one-half inch (13mm) nor more than 1 1/2 inches (38mm) apart. The clear area through the mesh must not be less than the internal unobstructed area of the required pipe.
(9) Where vents are provided with flame screens, the closure device shall be situated so as not to damage these screens.
(10) The diameter of each vent pipe must not be less than 1 1/2 inches nominal pipe size for fresh water tanks, 2 inches nominal pipe size for water ballast tanks, and 2 1/2 inches nominal pipe size for fuel oil tanks, except that small independent tanks need not have a vent more than 25% greater in cross-sectional area than the fill line.
(11)(i) If a tank may be filled by a pressure head exceeding that for which the tank is designed, the aggregate cross-sectional area of the vents in each tank must be not less than the cross-sectional area of the filling line unless the tank is protected by overflows, in which case the aggregate cross-sectional area of the overflows must be not less than the cross-sectional area of the filling line.
(ii) Provision must be made to guard against liquids rising in the venting system to a height that would exceed the design head of a cargo tank or fuel-oil tank. It may be made by high-level alarms or overflow-control systems or other, equivalent means, together with gauging devices and procedures for filling cargo tanks.
(12) Where deep tanks are intended for the occasional carriage of dry or liquid cargo, a spectacle or ring and blank flange may be fitted in the overflow pipe so arranged as not to interfere with venting when the tanks contain oil.
(13) Vents from fresh water or water ballast tanks shall not be connected to a common header with vents from oil or oily ballast tanks.
(b) Tank vents must remain within the watertight subdivision boundaries in which the tanks they vent are located. Where the structural configuration of a vessel makes meeting this requirement impracticable, the Marine Safety Center may permit a tank vent to penetrate a watertight subdivision bulkhead. All tank vents which penetrate watertight subdivision bulkheads must terminate above the weather deck.
[CGFR 6882, 33 FR 18843, Dec. 18, 1968, as amended by CGD 77140, 54 FR 40610, Oct. 2, 1989; CGD 83043, 60 FR 24774, May 10, 1995; CGD 95012, 60 FR 48050, Sept. 18, 1995]
§ 56.50-90 Sounding devices.
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(a) Each tank must be provided with a suitable means of determining liquid level. Except for a main cargo tank on a tank vessel, each integral hull tank and compartment, unless at all times accessible while the vessel is operating, must be fitted with a sounding pipe.
(b) Where sounding pipes terminate below the freeboard deck on cargo vessels, they shall be fitted with gate valves. On passenger vessels, where sounding pipes terminate below the bulkhead deck, they shall be fitted with self-closing gate valves.
(c) Except as allowed by this paragraph, on each vessel constructed on or after June 9, 1995, no sounding pipe used in a fuel-oil tank may terminate in any space where the risk of ignition of spillage from the pipe might arise. None may terminate in a space for passengers or crew. When practicable, none may terminate in a machinery space. When the Commanding Officer, Marine Safety Center, determines it impracticable to avoid terminating a pipe in a machinery space, a sounding pipe may terminate in a machinery space if all the following requirements are met:
(1) In addition to the sounding pipe, the fuel-oil tank has an oil-level gauge complying with paragraph (d) of this section.
(2) The pipe terminates in a place remote from ignition hazards unless precautions are taken such as fitting an effective screen (shield) to prevent the fuel oil, in case of spillage through the end of the pipe, from coming into contact with a source of ignition.
(3) The end of the pipe is fitted with a self-closing blanking device and a small-diameter, self-closing control cock located below the blanking device for the purpose of ascertaining before the blanking device is opened that no fuel oil is present. Provision must be made to ensure that no spillage of fuel oil through the control cock involves an ignition hazard.
(d) On each vessel constructed on or after June 9, 1995, other oil-level gauges may be used instead of sounding pipes if all the following requirements are met:
(1) In a passenger vessel, no such gauge may require penetration below the top of the tank, and neither the failure of a gauge nor an overfilling of the tank may permit release of fuel into the space.
(2) In a cargo vessel, neither the failure of such a gauge nor an overfilling of the tank may permit release of fuel into the space. The use of cylindrical gauge-glasses is prohibited. The use of oil-level gauges with flat glasses and self-closing valves between the gauges and fuel tanks is acceptable.
(e) The upper ends of sounding pipes terminating at the weather deck shall be closed by a screw cap or plug. Great Lakes dry cargo carriers may have the sounding pipes which service ballast water tanks terminate at least 4 inches above the deck if closure is provided by a tight fitting hinged cover making metal-to-metal contact with the hinge on the forward side. Positive means to secure these caps in the closed position shall be provided. Provision shall be made to prevent damage to the vessels' plating by the striking of the sounding rod.
(f) On mobile offshore drilling units where installation of sounding pipes may not be practicable for some tanks, alternate means of determining liquid level may be used if approved by the Commandant.
[CGFR 6882, 33 FR 18843, Dec. 18, 1968, as amended by CGD 73251, 43 FR 56800, Dec. 4, 1978; CGD 83043, 60 FR 24774, May 10, 1995; CGD 95028, 62 FR 51201, Sept. 30, 1997]
§ 56.50-95 Overboard discharges and shell connections.
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(a)(1) All inlets and discharges led through the vessel's side shall be fitted with efficient and accessible means, located as close to the hull penetrations as is practicable, for preventing the accidental admission of water into the vessel either through such pipes or in the event of fracture of such pipes.
(2) The number of scuppers, sanitary discharges, tank overflows, and other similar openings in the vessel's side shall be reduced to a minimum, either by making each discharge serve for as many as possible of the sanitary and other pipes, or in any other satisfactory manner.
(3) In general, when the bulkhead deck is above the freeboard deck, the requirements of this section apply relative to the bulkhead deck. For vessels not assigned load lines, such as certain inland vessels and barges, the weather deck shall be taken as the freeboard deck.
(b)(1) Scuppers and discharge pipes originating at any level and penetrating the shell either more than 17 1/2 inches (450mm) below the freeboard deck or less than 23 1/2 inches (600mm) above the summer load waterline must be provided with an automatic nonreturn valve at the shell. This valve, unless required by paragraph (b)(2) of this section, may be omitted if the piping is not less than Schedule 80 in wall thickness for nominal pipe sizes through 8 inches, Schedule 60 for nominal pipe sizes above 8 inches and below 16 inches, and Schedule 40 for nominal pipe sizes 16 inches and above.
(2) Discharges led through the shell originating either from spaces below the freeboard deck or from within enclosed superstructures and equivalent deckhouses on the freeboard deck as defined in §42.1315(i) of subchapter E (Load Lines) of this chapter, shall be fitted with efficient and accessible means for preventing water from passing inboard. Normally each separate discharge shall have one automatic nonreturn valve with a positive means of closing it from a position above the freeboard deck. Where, however, the vertical upward distance from the summer load line to the inboard end of the discharge pipe through which flooding can take place exceed 0.01L, the discharge may have two automatic nonreturn valves without positive means of closing, provided that the inboard valve is always accessible for examination under service conditions. Where that vertical distance exceeds 0.02L a single automatic nonreturn valve without positive means of closing is acceptable. In an installation where the two automatic nonreturn valves are used, the inboard valve must be above the tropical load line. The means for operating the positive action valve shall be readily accessible and provided with an indicator showing whether the valve is open or closed. A suitable arrangement shall be made to insure the valve is not closed by unauthorized persons, and a notice shall be posted in a conspicuous place at the operating station to the effect that the valve shall not be closed except as required in an emergency.
(3) Where scuppers and drains are installed in superstructures or deckhouses not enclosed as defined in §42.1315(j) of subchapter E (Load Lines) of this chapter, they shall be led overboard. Refer to paragraph (b)(1) of this section for any nonreturn valve requirement.
(4) Sanitary pump discharges leading directly overboard or via a holding tank must meet the standards prescribed by this paragraph. The location of the sanitary system openings within the vessel determines whether the requirements of paragraph (b)(2) or (3) of this section are applicable.
(c) Overflow pipes which discharge through the vessel's side must be located as far above the deepest load line as practicable and fitted with valves as required by paragraph (b) of this section. Two automatic nonreturn valves must be used unless it is impracticable to locate the inboard valve in an accessible position, in which case a nonreturn valve with a positive means of closure from a position above the freeboard deck will be acceptable. Overflows which extend at least 30 inches above the freeboard deck before discharging overboard may be fitted with a single automatic nonreturn valve at the vessel's side. Overflow pipes which serve as tank vents must not be fitted with positive means of closure without the specific approval of the Marine Safety Center. Overflow pipes may be vented to the weather.
(d)(1) Sea inlets and discharges, such as used in closed systems required for the operation of main and auxiliary machinery, as in pump connections or scoop injection heat exchanger connections, need not meet the requirements of paragraphs (b) (1) and (2) of this section but instead shall be fitted with a shutoff valve located as near the shell plating as practicable, and may be locally controlled if the valve is located in a manned machinery space. These controls shall be readily accessible above the floor plates and shall be provided with indication showing whether the valve is opened or closed. Manned machinery spaces include the main machinery space and are either attended by the crew or are automated in accordance with part 62 of this subchapter to be comparable to an attended space.
(2) In unmanned machinery spaces, all machinery inlets and discharges as described in paragraph (d)(1) of this section shall be remotely operable from a position above the freeboard deck unless otherwise approved and shall meet the access and marking requirements of paragraph (b)(2) of this section.
(e)(1) Pipes terminating at the shell plating shall be fitted with bends or elbows between the outboard openings and the first rigid connection inboard. In no case shall such pipes be fitted in a direct line between the shell opening and the first inboard connection.
(2) Seachests and other hull fittings shall be of substantial construction and as short as possible. They shall be located as to minimize the possibility of being blocked or obstructed.
(3) The thickness of inlet and discharge connections outboard of the shutoff valves, and exclusive of seachests, must be not less than that of Schedule 80 for nominal pipe sizes through 8 inches, Schedule 60 for nominal pipe sizes above 8 inches and below 16 inches, and Schedule 40 for nominal pipe sizes 16 inches and above.
(f) Valves required by this section and piping system components outboard of such required valves on new vessel installations or replacements in vessels of 150 gross tons and over shall be of a steel, bronze, or ductile cast iron specification listed in Table 56.601(a). Lead or other heat sensitive materials having a melting point of 1,700 °F. or less shall not be used in such service, or in any other application where the deterioration of the piping system in the event of fire would give rise to danger of flooding. Brittle materials such as cast iron shall not be used in such service. Where nonmetallic materials are used in a piping system, and shell closures are required by this section, a positive closure metallic valve is required (see also §56.6025).
(g) The inboard openings of ash and rubbish-chute discharges shall be fitted with efficient covers. If the inboard opening is located below the freeboard deck, the cover shall be watertight, and in addition, an automatic nonreturn valve shall be fitted in the chute in any easily accessible position above the deepest load line. Means shall be provided for securing both the cover and the valve when the chute is not in use. When ash-ejectors or similar expelling devices located in the boilerroom have the inboard openings below the deepest load line, they shall be fitted with efficient means for preventing the accidental admission of water. The thickness of pipe for ash ejector discharge shall be not less than Schedule 80.
(h) Where deck drains, soil lines, and sanitary drains discharge through the shell in way of cargo tanks on tank vessels, the valves required by this section shall be located outside the cargo tanks. These valves shall meet the material requirements of paragraph (f) of this section. The piping led through such tanks shall be fitted with expansion bends where required, and shall be of steel pipe having a wall thickness of not less than five-eighths inch, except that the use of suitable corrosion-resistant material of lesser thickness will be given special consideration by the Commandant. All pipe joints within the tanks shall be welded. Soil lines and sanitary drains which pass through cargo tanks shall be provided with nonreturn valves with positive means of closing or other suitable means for preventing the entrance of gases into living quarters.
(i) Except as provided for in §58.2020(c) of this chapter, sea valves must not be held open with locks. Where it is necessary to hold a discharge or intake closed with a lock, either a locking valve may be located inboard of the sea valve, or the design must be such that there is sufficient freedom of motion to fully close the locked sea valve after an event, such as fire damage to the seat, causes significant leakage through the valve. Valves which must be opened in and emergency, such as bilge discharges or fire pump suctions must not be locked closed, whether they are sea valves or not.
[CGFR 6882, 33 FR 18843; Dec. 18, 1968, as amended by CGFR 69127, 35 FR 9979, June 17, 1970; CGFR 7259R, 37 FR 6189, Mar. 25, 1972; CGD 81030, 53 FR 17837, May 18, 1988; CGD 77140, 54 FR 40610, Oct. 2, 1989]
§ 56.50-96 Keel cooler installations.
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(a) Keel cooler installations shall meet the requirements of §56.5095(d)(1) and (2), and (e)(3), and (f) except that shutoff or isolation valves will not be required for the inlet and discharge connections if:
(1) The installation is forward of the collision bulkhead; or,
(2) The installation is integral with the ship's hull such that the cooler tubes are welded directly to the hull of the vessel with the hull forming part of the tube and satisfies all of the following:
(i) The cooler structure is fabricated from material of the same thickness and quality as the hull plating to which it is attached except that in the case of half round pipe lesser thickness may be used if specifically approved by the Commandant. In any case the structure, with the exception of the hull proper, need not exceed three-eighths inch in thickness.
(ii) The flexible connections and all openings internal to the vessel, such as expansion tank vents and fills, in the installation are above the deepest load line and all piping components are Schedule 80 or thicker below the deepest load line.
(iii) Full penetration welds are employed in the fabrication of the structure and its attachment to the hull.
(iv) The forward end of the structure must be faired to the hull such that the horizontal length of the fairing is no less than four times the height of the structure, or be in a protected location such as inside a bow thruster trunk.
[CGFR 6882, 33 FR 18843, Dec. 18, 1968, as amended by CGFR 7259R, 37 FR 6189, Mar. 25, 1972; CGD 77140, 54 FR 40611, Oct. 2, 1989]
§ 56.50-97 Instrument, control and sampling piping (modifies 122.3).
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(a) Instrument, control and sampling piping must comply with paragraph 122.3 of ANSI-B31.1 except that:
(1) Soldered type fittings may not be used.
(2) The outside diameter of takeoff connections may not be less than 0.840 inches for service conditions up to 900 psi or 800 °F., and 1.050 inches for conditions that exceed either of these limits.
[CGFR 6882, 33 FR 18843, Dec. 18, 1968, as amended by CGFR 69127, 35 FR 9978, June 17, 1970; CGD 73254, 40 FR 40165, Sept. 2, 1975]
§ 56.50-103 Fixed oxygen-acetylene distribution piping.
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(a) This section applies to fixed piping installed for the distribution of oxygen and acetylene carried in cylinders as vessels stores.
(b) The distribution piping shall be of at least standard wall thickness and shall include a means, located as close to the supply cylinders as possible, of regulating the pressure from the supply cylinders to the suitable pressure at the outlet stations.
(c) Acetylene distribution piping and pipe fittings must be seamless steel. Copper alloys containing less than 65 percent copper may be used in connection with valves, regulators, gages, and other equipment used with acetylene.
(d) Oxygen distribution piping and pipe fittings must be seamless steel or copper.
(e) When more than two cylinders are connected to a manifold, the supply pipe between each cylinder and manifold shall be fitted with a non-return valve.
(f) Except for the cylinder manifolds, acetylene is not to be piped at a pressure in excess of 100 kPa (14.7 psi).
(g) Pipe joints on the low pressure side of the regulators shall be welded.
(h) Branch lines shall not run through unventilated spaces or accommodation spaces.
(i) Relief valves or rupture discs shall be installed as relief devices in the piping system if the maximum design pressure of the piping system can be exceeded. The relief device set pressure shall not exceed the maximum design pressure of the piping system. Relief devices shall discharge to a location in the weather at least 3 m (10 ft) from sources of ignition or openings to spaces or tanks.
(j) Outlet stations are to be provided with suitable protective devices which will prevent the back flow of gas into the supply lines and prevent the passage of flame into the supply lines.
(k) Shutoff valves shall be fitted at each outlet.
[CGD 95028, 62 FR 51201, Sept. 30, 1997]
§ 56.50-105 Low-temperature piping.
top
(a) Class I-L. Piping systems designated to operate at temperatures below 0 °F. and pressures above 150 pounds per square inch gage shall be of Class I-L. Exceptions to this rule may be found in the individual requirements for specific commodities in subchapters D, I, and O of this chapter. The following requirements for Class I-L piping systems shall be satisfied:
(1) Materials. All materials used in low temperature piping systems shall be selected from among those specifications listed in Table 56.50105 and shall satisfy all of the requirements of the specifications, except that:
(i) The minimum service temperature as defined in §54.2510(a)(2) of this subchapter shall not be colder than that shown in Table 56.50105; and
(ii) The material shall be tested for low temperature toughness using the Charpy V-notch specimen of ASTM E 23 (incorporated by reference, see §56.012), Notched Bar Impact Testing of Metallic Materials, Type A, Figure 4. The toughness testing requirements of subpart 54.05 of this subchapter shall be satisfied for each particular product form. Charpy V-notch tests shall be conducted at temperatures not warmer than 10 °F. below the minimum service temperature of the design, except that for service temperatures of 320 °F. and below, the impact test may be conducted at the service temperature. The minimum average energy shall not be less than that shown in Table 56.50105. In the case of steels conforming to the specifications of Table 54.2520(a) of this subchapter the minimum lateral expansion shall not be less than that required in §54.2520 of this subchapter. The minimum energy permitted for a single specimen and the minimum subsize energies shall be those obtained by multiplying the average energy shown in Table 56.50105 by the applicable fraction shown in Table 56.50105(a).
Table 56.50-105(a)_Charpy V-Notch Energy Multiplying Factors
------------------------------------------------------------------------
Factor for Factor for
minimum minimum
energy, energy
Charpy V-notch specimen size \1\ average of single
3 specimens specimen
\1\ \1\
------------------------------------------------------------------------
10x10 mm...................................... 1 2/3
10x7.5 mm..................................... 5/6 5/9
10x5.0 mm..................................... 2/3 4/9
10x2.5 mm..................................... 1/2 1/3
------------------------------------------------------------------------
\1\ Straight line interpolation for intermediate values is permitted.
(iii) Steels equivalent to those listed in Table 56.50105 of this part, but not produced according to a particular ASTM specification, may be used only with the prior consent of the Marine Safety Center. Steels differing in chemical composition, mechanical properties or heat treatments from those specified may be specially approved by the Marine Safety Center. Similarly, aluminum alloys and other nonferrous materials not covered in Table 56.50105 of this part may be specifically approved by the Marine Safety Center for service at any low temperature. There are restrictions on the use of certain materials in this part and in subchapter O of this chapter.
(2) Piping weldments. Piping weldments shall be fabricated to satisfy the requirements of §57.031(b) of this subchapter in addition to subpart 56.70. Toughness testing of production weldments for low temperature piping systems and assemblies is not required.
(3) Postweld heat treatment. All piping weldments shall be postweld heat treated for stress relief in accordance with the procedures of subpart 56.85. The only exceptions to this requirement are for materials which do not require postweld heat treatment as shown in Table 56.8510. Relief from postweld heat treatment shall not be dependent upon pipe thickness or weld joint type.
(4) Nonacceptable joints. Single welded butt joints with backing ring left in place, socket welds, slip-on flanges, pipe joining sleeves, and threaded joints shall not be used, except in small diameter instrument lines.
(5) Other requirements. All other requirements of this part for Class I piping apply to Class I-L piping. Pressure testing must comply with subpart 56.97 of this part, and nondestructive testing of circumferentially welded joints must comply with §56.9510. Seamless tubular products must be used except that, when the service pressure does not exceed 1724 KPa (250 psi), the Commanding Officer, Marine Safety Center, may give special consideration to appropriate grades of piping and tubing that are welded without the addition of filler metal in the root pass. Each production procedure and quality-control program for welded products must be acceptable to the Officer in Charge, Marine Inspection.
(b) Class II-L. Piping systems designed to operate at temperatures below 0 °F. and pressures not higher than 150 pounds per square inch gage shall be of Class II-L. Exceptions to this rule may be found in the individual requirements for specific commodities in subchapter D (Tank Vessels) and I (Cargo and Miscellaneous Vessels) of this chapter. The following requirements for Class II-L piping systems shall be satisfied:
(1) Materials must be the same as those required by paragraph (a)(1) of this section except that pipe and tubing of appropriate grades welded without the addition of a filler metal may be used. The Commandant may give special consideration to tubular products welded with the addition of filler metal.
(2) Piping weldments shall be fabricated to satisfy the requirements of §57.031(b) of this subchapter in addition to subpart 56.70. Toughness testing of production weldments for low temperature piping systems and assemblies is not required.
(3) All piping weldments shall be postweld heat treated for stress relief in accordance with the procedures of subpart 56.85. The only exceptions to this requirement are for materials which do not require postweld heat treatment as shown in Table 56.8510 and for socket weld joints and slip-on flange weld attachments where the weld thickness does not exceed that exempted by this table. Otherwise, relief from post-weld heat treatment shall not be dependent upon pipe thickness or weld joint type.
(4) Socket welds in nominal sizes above 3 inches, slip-on flanges in nominal sizes above 4 inches, and threaded joints in sizes above 1 inch shall not be used.
(5) Pressure testing must comply with Subpart 56.97, and nondestructive testing of welded joints must comply with §56.9510.
(6) All other requirements contained in this part for Class II piping shall be applicable to Class II-L systems, except that §56.7015(b)(3)(iv) shall not apply.
Table 56.50-105_Acceptable Materials and Toughness Test Criteria \2\
----------------------------------------------------------------------------------------------------------------
ASTM specification Minimum service Minimum avg Charpy
Product form \3\ Grade \4\ temperature V notch energy
----------------------------------------------------------------------------------------------------------------
Pipe............................ 1................. -30 °F........ 20 ft. lb.
3................. -150 °F....... 25 ft. lb.
Tube (carbon and low A-333 and 4 (A-333 only).... -100 °F....... 25 ft. lb.
alloy steels). A-334............. 6................. -30 °F........ 20 ft. lb.
7................. -100 °F....... 25 ft. lb.
8................. -320 °F....... Refer to §
54.25-20 of this
subchapter.
Pipe (Austenitic stainless A-312............. All Grades........ No limit.......... Austenitic
steel). stainless steel
piping need be
impact tested
only when
toughness tests
are specified in
subpart 54.25 of
this subchapter
for plating of
the same alloy
designation. When
such toughness
tests are
required, the
minimum average
energy is 25 ft.
lb.
Wrought welding fittings WPL1.............. -30 °F........ 20 ft. lb.
(carbon and low alloy A-420............. WPL3.............. -150 °F....... 25 ft. lb.
steels). WPL4.............. -100 °F....... 25 ft. lb.
Forged or rolled flanges, LF1............... -30 °F........ 20 ft. lb.
forged fittings, valves A-350 \1\......... LF2............... -30 °F........ 20 ft. lb.
and pressure parts LF3............... -150 °F....... 25 ft. lb.
(carbon and low alloy LF4............... -100 °F....... 25 ft. lb.
steels).
Forged or rolled flanges, forged A-182............. Austenitic grades No limit.......... These products
fittings, valves and pressure only (304, 304H, need be impact
parts (high alloy steels). 304L, 310, 316, tested only when
316H, 316L, 321, toughness tests
321H, 347, 347H, are specified in
348, 348H). subpart 54.25 of
this subchapter
for plating of
the same alloy
designation. When
such toughness
tests are
required, the
minimum averageenergy is 25 ft. (continued)