water leg and at least 2 handholes or washout plugs near the line of the lower tube sheet.

(d) A fire door or other access opening not less than 11 by 15 inches or 10 by 16 inches or 15 inches in diameter shall be provided for the furnace of an internally fired boiler in which the least furnace dimension is 28 inches or over.

(e) Washout plugs shall be made of nonferrous material and be of not less than 2 inches pipe size.

(f) Washout openings may be used for return pipe connections and the washout plug placed in a tee so that the plug is directly opposite and as close as possible to the opening in the boiler.

(g) All threaded openings shall be tapped into material having a minimum thickness as specified for the various pipe sizes in table 53.03-50 (g).

TABLE 53.03-50 (g)-MINIMUM THICKNESS OF MATE RIAL FOR THREADED CONNECTIONS

(h) Flanged pipe connections to boilers shall conform to the standards given in table 55.07-15 (e5) of Part 55 of this subchapter for the corresponding pipe sizes.

CGFR 48-23, 13 F. R. 3525, June 26, 1948, as amended by CGFR 49-18, 14 F. R. 5086, Aug. 17, 1949]

§ 53.03-55 Installation. (a) Feed or make-up water shall not be discharged directly into any part of a boiler exposed to the radiant heat of the fire. Feed water shall not be introduced through the openings or connections used for the water column, the water gauge, or the gauge cocks.

(b) Hot water systems shall be so installed that there will be no opportunity for the fluid-relief column to be accidentally shut off.

(c) When a stop valve is used in the supply pipe connection of a single boiler, there shall be one used in the return pipe connection.

(d) A stop valve shall be used in each supply and return pipe connection if more than one boiler is connected to a common system.

(e) Provision shall be made for cleaning the interior of the return piping at or close to the boiler.

(f) When stop valves are used they shall be properly designated on tags of metal or other durable material as indicated by the following:

Supply valve-Number (). Do not close without also closing return valve-Number ().

Return valve-Number (). Do not close without also closing supply valve-Number ().

(g) After installation the boiler shall be hydrostatically tested to twice the pressure at which the safety or relief valve is set to open.

CGFR 48-23, 13 F. R. 3525, June 26, 1948]

§ 53.03-60 Safety valves. (a) Each steam heating boiler shall have one or more approved safety valves set to discharge at a pressure of not to exceed 30 p. s. i., and designed, constructed and flow-tested for actual capacity in conformance with Subpart 162.012 of Subchapter Q (Specifications) of this chapter.

(b) The minimum safety valve capacity in pounds per hour shall be determined by dividing the maximum B. t. u. output at the boiler nozzle obtained by the firing of any fuel, for which the unit is designed, by 1,000 or by multiplying the square feet of heating surface by 5. In many cases a greater relieving capacity of valves will have to be provided than the minimum specified by these regulations. In all cases the requirements of paragraph (c) of this section shall be met.

(c) The steam safety valve capacity for each boiler shall be such that with the fuel-burning equipment installed. the pressure cannot rise more than 6 percent above the maximum allowable pressure of the boiler. For set pressures not exceeding 15 p. s. i., the safety valve capacity may be such that with the fuelburning equipment installed, the pressure

cannot rise more than 5 pounds above the maximum allowable pressure.

(d) When operating conditions are changed, or additional boiler heating surface is installed, the safety valve capacity shall be increased, if necessary, to meet the new conditions and be in accordance with paragraph (c) of this section. The additional safety valves may be installed on the outlet piping provided there is no intervening valve. [CGFR 52-43, 17 F. R. 9347, Oct. 18, 1952]

§ 53.03-62 Relief valves. (a) Each hot-water heating or hot-water supply boiler shall have one or more approved relief valves set to relieve at a pressure not to exceed 30 p. s. i., and designed, constructed and flow-tested for actual capacity in conformance with Subpart 162.013 of Subchapter Q (Specifications) of this chapter.

(b) The steam relieving capacity in pounds per hour shall be determined by dividing the maximum B. t. u. output at the boiler nozzle obtained by the firing of any fuel, for which the unit is designed, by 1,000 or by multiplying the square feet of heating surface by 5. In many cases a greater relieving capacity of valves will have to be provided than that minimum specified by the regulations in this subpart. In every case, the requirements of paragraph (c) of this section shall be met.

(c) The relief valve capacity for each boiler shall be such that with any fuel burning equipment installed the pressure cannot rise more than 3 pounds per square inch above the maximum allowable pressure of the boiler.

[CGFR 52-43, 17 F. R. 9348, Oct. 18, 1952]

§ 53.03-63 Installation of safety and relief valves. (a) Safety and relief valves shall be installed with the spindle vertical, if possible, and may be connected directly to the boiler, or to a fitting connected to the boiler by a close nipple, or to a Y base or valveless steam or water pipe between adjacent boilers, or to a valveless header connecting steam or water outlets in the same boiler. Safety and relief valves shall not be connected to an internal pipe in the boiler.

(b) When a Y base is used the inlet area shall be not less than the combined outlet areas.

(c) When the size of the boiler requires a safety or relief valve larger than 4 inches in diameter, two or more valves having the required combined capacity

218039-53-21

shall be used. When two or more valves are used on a boiler, they may be single, directly attached, or mounted on a Y base.

(d) No shut-off of any description shall be placed between the safety or relief valve and the boiler, nor on discharge pipes between such valves and the atmosphere.

(e) The escape from safety or relief valves shall be fitted with discharge piping so arranged that there is no danger of scalding operating personnel.

(f) The area of the discharge pipe shall be not less than the area of the valve or aggregate area based on the nominal diameters of the valves with which it connects. The discharge pipe shall be fitted with an open drain to prevent water from lodging in the upper part of the valve or in the pipe. When an elbow is placed on a safety- or reliefvalve discharge pipe, it shall be located close to the valve outlet.

[CGFR 52-9, 17 F. R. 7651, Aug. 21, 1952]

§ 53.03-70 Fittings and appliances(a) Steam gauges. (1) Each steam boiler shall have a steam gauge connected to its steam space, or to its water column, or to its steam connection by means of a siphon or equivalent device exterior to the boiler and of sufficient capacity to keep the gauge tube filled with water and so arranged that the gauge cannot be shut off from the boiler except by a cock, with T or lever handle, placed in the pipe near the gauge. The handle of the cock shall be parallel to the pipe on which it is located when the cock is open.

(2) Connections to steam gauge siphon shall be of nonferrous metal when smaller than 1 inch pipe and longer than 5 feet between the siphon and point of connection of pipe to boiler, and also when smaller than 1⁄2 inch pipe size and shorter than 5 feet between the siphon and point of connection of pipe to boiler.

(3) The scale on the dial of the gauge shall be graduated to not less than 30 p. s. i. The gauge shall be provided with effective stops for indicating pointer at the zero point. The travel of the pointer from zero to 30 p. s. i. shall be at least 3 inches.

(b) Water pressure gauges. (1) Each hot water boiler shall have a pressure gauge connected to it or to its flow connection in such a manner, that it cannot be shut off from the boiler except

Page 305

by a cock, with T or lever handle, placed on the pipe near the gauge. The handle of the cock shall be parallel to the pipe on which it is located when the cock is open.

(2) Pressure gauge connections shall be of nonferrous material when smaller than 1 inch pipe size and longer than 5 feet between gauge and point of connection of pipe to boiler, and also when smaller than 1⁄2 inch pipe size and shorter than 5 feet between gauge and point of connection of pipe to boiler.

(c) Thermometers. (1) Each hotwater boiler shall have a thermometer so located and connected that the temperature may be read at the same time as the water pressure is being observed.

(2) The thermometer shall be so located that it shall at all times indicate the temperature in degrees Fahrenheit of the water in the boiler or near the outlet.

(d) Temperature combustion regulator. A temperature combustion regulator, which will control the rate of combustion to prevent the temperature of the water from rising above 250° F. at or near the outlet, or a thermostatic device which will relieve the pressure on the boiler when the temperature exceeds 250° F. shall be installed on each hot water heating boiler.

(e) Pressure control regulator. When a pressure control regulator is used, it shall operate and prevent the steam pressure from rising above 30 p. s. i.

(f) Bottom blowoff. Each boiler shall have a blowoff pipe connection fitted with a valve or cock of not less than 34 inch pipe size connected to the lowest water space available.

(g) Water gauge glasses. Each steam boiler shall have one or more water gauge glasses attached to the water column or boiler by means of valved fittings with the lower fitting provided with a valve or pet cock.

(h) Gauge cocks. Each steam boiler shall have two or more gauge cocks loIcated within the visible range of the water glass.

(1) Water column pipes. The minimum size of pipes connecting a water column to a steam boiler shall be 1 inch. No connections, except for regulator, drain or steam gauge, shall be attached to a water column or the piping connecting a water column to a boiler. If the water column or gauge glass is connected

to the boiler by pipe and fittings, a T, or equivalent fitting, in which a drain valve and piping may be attached, shall be installed in the water piping connection at every right angle turn to facilitate cleaning.

(j) Automatic low-water fuel cut-off. (1) Each automatically-fired steam boiler shall be equipped with an automatic low-water fuel cut-off, so located as to automatically cut off the fuel supply when the surface of the water falls below the lowest safe water level. If a water-feeding device is installed in conjunction with the required low-water fuel cut off, it shall be so constructed that the water inlet valve cannot feed water into the boiler through the float chamber and so located as to supply the required amount of feed-water when the surface of the water falls to the lowest safe water level. This point shall be not lower than the lowest visible part of the water glass.

(2) The fuel or feed-water control device may be attached direct to the boiler or to the tapped openings provided for attaching a water glass direct to a boiler, provided that such connections from the boiler are non-ferrous T's or Y's not less than 11⁄2-inch pipe size between the boiler and the water glass, so that the water glass is attached direct and as close as possible to the boiler. The straightway tapping of the Y or T shall take the water glass fitting, and the side outlet of the Y or T shall take the fuel cut-off or water-feeding device.

(3) Low water cut-off devices employing a float and float bowl shall have a vertical straight-a-way valved drain pipe at the lowest point in the water equalizing pipe connection by which the bowl and equalizing pipe can be flushed and the device tested.

[CGFR 52-9, 17 F. R. 7651, Aug. 21, 1952]

§ 53.03-75 Hydrostatic tests, inspection, and stamping. (a) Each boiler shall be subject to a hydrostatic test pressure of not less than 60 pounds per square inch by the manufacturer.

(b) In the event of any defects developing, the defective material may be replaced and the boiler retested.

(c) Individual shop inspection of heating boilers by an inspector is not required. Such inspection shall be made by the manufacturer while the boiler is subjected to the required hydrostatic test

pressure to insure that there are no defects in workmanship and materials.

(d) Steel plate heating boilers of the automatically controlled packaged type shall be subjected to such operating tests as may be prescribed by the Commandant.

(e) Upon completion of the hydrostatic test and inspection and after the boiler is found acceptable it shall be stamped in a suitable location so as to be readily visible, with the following data:

(Name of fabricator and serial number)

(Month and year fabricated)

-p. s. 1. (Maximum w. p.) (Steam or water) B. t. u. per hour, or pounds per hour. (Safety or relief valve capacity, minimum)

(Coast Guard Approval No.)

[CGFR 52-9, 17 F. R. 7651, Aug. 21, 1952] SUBPART 53.05-CAST-IRON HEATING BOILERS

SOURCE: §§ 53.05-1 to 53.05-50 contained in CGFR 48-23, 13 F. R. 3526, June 26, 1948, except as otherwise noted.

$ 53.05-1 Scope. The regulations in this subpart contain detail requirements for the design and construction of castiron heating boilers.

Manufacturer's

certifica

§ 53.05-5 tion. A manufacturer desiring to fabricate cast-iron heating boilers for use on vessels subject to inspection by the Coast Guard shall submit an affidavit on Form CG-935A certifying that such boilers will comply with all the applicable requirements of the regulations in this subchapter.

§ 53.05-10 Material. The material used in the fabrication of cast-iron heating boilers shall conform to the requirements of Subpart 51.61 of this subchapter for grade B or grade C cast iron. [CGFR 48-23, 13 F. R. 3526, June 26, 1948; CGFR 52-62, 17 F. R. 11875, Dec. 31, 1952]

§ 53.05-30 Hydrostatic tests, inspection, and stamping. (a) The completed boiler shall be subject to a hydrostatic test pressure of not less than 60 pounds per square inch by the manufacturer.

(b) In the event of any defects developing, the defective cored section may be replaced and the boiler retested.

(c) The requirements of § 53.03-75 (c) and (d) apply to cast-iron heating boilers.

(d) (1) All cast-iron heating boilers shall be plainly and permanently marked, stamped, or cast with the following data: (1)

(Name of fabricator and serial number). (ii)

(Month and year fabricated). (iii)

p. s. 1. (Maximum w. p.) (Steam or water). iv) pounds per hour or B. t. u. per hour. (Safety or relief valve capacity, minimum).

(v) Coast Guard Approval No.

(2) Items (i), (ii), and (iii) shall be stamped or cast on all cored sections of the boiler. In addition, a name plate containing all the markings listed herein shall be attached in a suitable location on the outside of the completed boiler or casing.

[CGFR 48-23, 13 F. R. 3527, June 26, 1948, as amended by CGFR 52-9, 17 F. R. 7652, Aug. 21, 1952]

§ 53.05-35 Installation. The provisions of § 53.03-55 shall apply to castiron boilers.

§ 53.05-40 Safety and relief valves. (a) The provisions of §§ 53.03-60, 53.0362 and 53.03-63 shall apply to cast-iron heating boilers except as specified in this section.

(b) Safety and relief valves shall be set to discharge at a pressure not to exceed 15 pounds per square inch.

(c) Safety and relief valves for castiron heating boilers shall be such that with any fuel burning equipment installed, the pressure cannot rise above the maximum allowable pressure more than 5 pounds per square inch for a steam boiler and 3 pounds per square inch for a hot-water boiler.

[CGFR 52-43, 17 F. R. 9348, Oct. 18, 1952]

§ 53.05-50 Fittings and appliances. The provisions of § 53.03-70 shall apply to fittings and appliances for cast-iron boilers, except that the pressure control regulator shall operate to prevent the pressure from rising above 15 p. s. i. [CGFR 52-9, 17 F. R. 7652, Aug. 21, 1952]

AUTHORITY: 1 54 01-1 to 54.07-25 issued under N 8 4405, as amended, 4462, as amended. 46 U S. C. 375, 416. Interpret or apply N 2 4400, 4417, 4417a, 4418, 4426444 4454 4491, as amended, sec. 14, 29 Stat. d 41 Mtat 305, secs, 1, 2, 49 Stat. 1544, sco $ 34 Mtat 347, sec. 5. 55 Stat. 244, 245, as amendes 48 V8 C. 362, 363, 366, 367, 391,

454 404 412 435, 489, 1333. 50 U. S. C. A 143 & 0 10402, 17 F. R. 9917; 3 CFR, Tad supp

SOURCE: $ 54.01-1 to 54.07-25 contained in CGFR 52-9, 17 F. R. 7652, Aug. 21. 1952; CGFR 52-62, 17 F. R. 11875, Dec. 31, 1952. SUBPART 54.01-GENERAL REQUIREMENTS

§ 54.01-1 Scope. (a) The regulations in this part contain detail requirements for the design and construction of unfired pressure vessels subject to inspection by the Coast Guard.

(b) An unfired pressure vessel is subject to shop inspection when such a vessel may contain any of the following:

(1) Steam, gas, or vapors at pressures exceeding 15 pounds per square inch or temperatures exceeding 300° F. The shell, tubes, or coils of a heat exchanger shall be considered a pressure vessel if such parts may be subjected to steam, gas, or vapor pressures exceeding 15 pounds per square inch or temperatures exceeding 300° F.

(2) Fuel oil at pressures exceeding 100 pounds per square inch or temperatures exceeding 150° F.

(3) Lubricating oil at pressures exceeding 100 pounds per square inch or temperatures exceeding 200° F.

(4) Liquids, except fuel oil and lubricating oil, at pressures exceeding 100 pounds per square inch or temperatures exceeding 200° F.

(5) Liquids in compression tanks with air cushions of pressures exceeding 100 pounds per square inch.

(6) Stored or stowed dangerous articles, substances, or combustible liquids which are required by law or regulation to be carried in containers fabricated as a pressure vessel, irrespective of pressures, temperatures, or capacities, except such stored or stowed dangerous articles, substances, or combustible liquids which are permitted by Subchapter N (Explosives or Other Dangerous Articles or Substances and Combustible Liquids on Board Vessels) of this chapter to be carried in containers constructed in accordance with the requirements of the Interstate Commerce Commission.

(c) Unfired pressure vessels may be exempted from shop inspection when the internal volume does not exceed 5 cubic feet capacity and the design pressure does not exceed 100 pounds per square inch; however, such vessels shall otherwise comply with the requirements for materials, construction, welding and marking as specified in this subchapter.