1、MIL-B-1774C 45 m 7777906 0212345 3 W 10 January 1961 SUPERSEDING MIL-B- 17748B(SHIPS) 18 February 1958 MILITARY SPECIFICATION BOILERS, HEATING, LOW PRESSURE, HOT WATER NAVAL SHIPBOARD 1. SCOPE 1. 1 Scope. - This specification covers oil fired, straight fire, tube type hot water heating boilers for s
2、hipboard use. 1. 2 Classification. - The boilers shall be of the following classes, styles, and sizes, as specified (see 6. 1): Class I - Carbon steel construction. Class II - Nonmagnetic construction. Style A - Horizontal design. Style B - Vertical design. Size 1 - 150, O00 British thermal units (B
3、. t. u. )/ hour capacity. Size 2 - 250,000 B. t. u. /hour capacity. Size 3 - 350,000 B. t. u. /hour capacity. Size 4 - 450,000 B. t. u. /hour capacity. 1.2. 1 Capacity of the boiler is defined as quantity of heat, in B. t. u. /hour transferred into water forced circulated through the boiler, as meas
4、ured at the boiler hot water outlet, when the boiler is burning Diesel fuel oil conforming to Specification MIL-F- 16884. 2. APPLICABLE DOCUMENTS 2. 1 The following specifications, standards and drawing, of the issue in effect on date of invitation for bids, form a part of this specification to the
5、ex- tent specified herein. SPECIFICATIONS FEDERAL QQ-S-766 - Steel Plates, Sheets, and Strip - Corrosion Resisting. MILITARY MIL-R-196 - Repair Parts for Internal Com- bustion Engines, Packaging of. MIL-B-233 - Boxes, Repair Parts. MILITARY (Contd) MIL-D-963 - Drawings, Production, Procedure for Pro
6、cure- ment of. Technical: Reproduction Requirements for. MIL-P-15024 - Plates, Identification - Information and Marking for Identification of Elec- trical, Electronic and Mec hanical Equipment. Mechanical and Electrical Equipment (Less Elec- tronics). MIL-P-15137 - Provisioning and Technical Documen
7、tation for Re- pair Parts for Electrical and Mechanical Equip- ment (Naval Shipboard Use). MIL-I -16165 - Interference Shielding, Electrical Systems. MIL-P-16298 - Preservation, Packaging, Packing, and Marking of Electric Machine Having Rotating Parts and Associated Repair Parts. MIL-F- 16884 - Fuel
8、 Oil, Diesel, Marine. MIL- 1-16910 - Interference Measurement, Radio, Methods and Limits; 14 Kilocycles to 1000 Megacycles. Current, Fractional HP (Shipboard Use). Graphitic (Ductile Iron) (for Shipboard Applica- tions). Steam Turbines and Gears (Including Repair Parts, Tools, Accessories MIL-D-5480
9、 - Data, Engineering and MIL-M-15071 - Manual, Technical, for MIL-M-17059 - Motors, Alternating- MIL-I -17166 - Iron Castings; Nodular MIL-P-17286 - Propulsion and Auxiliary Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-E-37748C q5 7797706 O232
10、346 5 I MILITARY (Contd) and Instruments); Pack- aging of. Equipment and Associated Repair Parts, Prepara- tion for Delivery of. Fractional XP (Shipboard Use). MIL- 0-70327 -Drawings, Engineering and Associated Lists. MIL- E-17555 -Electronic and Electrical MIL-M-17556 -Motor, Direct-Current, STANDA
11、RDS MILITARY MIL-STD-22 - Welded-Joint Designs. MIL-STD-130 - Identification Marking of MIL-STD-278 - Welding and Allied Proc- U. S. Military Property. esses for Machinery or Ships of the United States Navy. DRAWING BUREAU OF SHIPS RE-49A501 - Coupling, Spherical Seat De- sign Data. (Copies of speci
12、fications, standards, drawings, and publications required by contractors in connec- tion with specific procurement functions should be obtained from the procuring activity or as directed by the contracting officer. ) 2.2 Other publications. - The following documents form a part of this specification
13、 to the extent speci- fied herein. Unless otherwise indicated, the issue in effect on date of invitation for bids.shal1 apply. AMERICAN SOCIETY OF MECHANICAL ENGINEERS SB-111 - Copper and Copper-Alloy Seam- less Condenser Tubes and Ferrule Stock. SB-171 - Copper-Alloy Condenser Tube Plates. Boiler C
14、onstruction Code. (Application for copies should be addressed to the American Society of Mechanical Engineers, 29 West Thirty-Ninth Street, New York, N.Y. ). OFFICIAL CLASSIFICATION COMMITTEE Uniform Freight Classification Rules. (Application for copies should be addressed to the Official Classifica
15、tion Committee, 1 Park Avenue at 33rd Street, New York 16, N. Y. ). 3. REQUIREMENTS 3. 1 Preproduction model. - One boiler shall be submitted to a laboratory satisfactory to the bureau or agency concerned for the preproduction inspection specified in 4.2. 1. 3.2 Electrical characteristics. - The boi
16、ler shall be designed to operate on the electric power supply of one of the following ratings, as specified (see 6.1): Direct Alternating current (a. c. current (d. c. 1 volts vas Phase Cycle 115 440 3 60 230 220 3 60 Special 110 3 60 230 Single - 115 Single - Special -I - 3.3 Material. - 3.3.1 Cast
17、 iron shall not be used in any part of the boiler. NoduIar iron conforming to Specification MIL-1-17166 may be used in boiler auxiliaries, ac- cessories, and controls, where no other substitute for cast iron is practicable, provided approval of the specific application is obtained from the bureau or
18、 agency concerned. 3.3.2 Class I - carbon steel construction. - Except as otherwise specified herein, material used in construction of class I boilers shall conform to the A. S. M. E. Boiler Construction Code. 3.3.3 Class - nonmagnetic construction. - 3.3.3.1 General requirements. - Boilers speci- f
19、ied herein are to be installed on ships whose mag- netic signature must be extremely low. Therefore great importance is attached to use of nonmagnetic materials wherever possible without involving de- velopment or affecting the design characteristics. Where experience with working parts mandates the
20、 use of magnetic ferrous materials in the absence of suitable nonmagnetic substitutes, such parts should be as widely dispersed as practicable. On the basis of this consideration, the use of ferrous materials in crankshafts, piston rings, cylinder liners, threaded parts, and ball bearings will be co
21、nsidered by the bureau or agency concerned if the contractor considers there is no suitable nonmagnetic substi- tute. Other parts of all components used in the boiler assembly shall be manufactured from 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,
22、-,-MIL-B-37748C 45 7777906 0232347 7 nonniagnetic materials. Except as otherwise spe- cified herein, material used in the construction of equipment shall be considered nonmagnetic if it has a permeability of less than 1. 08 before fabrication and not greater than 2. O after fabrication. Material use
23、d shall be fully identified on preliminary drawings (see 6.2) and on all drawings submitted by the con- tractor for approval after award of the contract or order (see 3. 10). 3.3.3. 2 Materials. - The following materials shall be used in the boiler shell assembly (including tubes): (a) 70-30 copper-
24、nickel alloy plate in accordance with A. S. M. E. Publication SB-171 for shell assembly proper and all pressure parts. (b) 90-10 copper-nickel alloy seamless tubes (annealed) in accordance with A. S. M. E. Publication SB-111 for tubes. classes 304, 321 or 347, low permeability, of Specification QQ-S
25、-766 may be used for such applications as breechings, cover plates, structural and support members, provided these members do not form an integral part of the pressure vessel and provided they are not welded or brazed to the pressure vessel. Bronze, brass or aluminum may also be used for supports an
26、d for jacket over the shell insulation. (d) Bronze or brass for valves, pipe fittings and piping incident to the boiler assembly, provided that the particular material is suitable for the purpose intended. (c) Steel, corrosion-resisting conforming to 3.3.3.3 Electrical equipment. - (a) All items of
27、electrical equipment shail be fabricated of nonmagnetic material, except for the following parts: (1) Parts required in the magnetic circuit of the particular item of equipment. (2) Structural parts of motors, rotary con- verters, contactors, relays, thermo- stats, and pressure switches which would
28、entail extensive modification and redesign to permit substitution of nonmagnetic material. (b) Electric controllers, solenoids, and switches shall have enclosure and panels of suitable nonmagnetic metals. (c) Stray magnetic fields caused by electrical circuits shall be kept to a minimum by making th
29、e area of electric current loops as small as possible and arranging adjacent loops so that the fields will be in opposition. Current loops shall enclose no magnetic material unless essential for proper per- formance of equipment. (d) In a. c. motors, all connections between stator winding connection
30、s shall be made as short as possible. The power leads to the stator winding shall be run through the same opening in the motor frame. 3.4 Radio interference suppression. - 3.4. 1 The boiler automatic high tension ignition and combustion control system shall be arranged to minimize radio interference
31、, both radiated and Con- ducted, through the use of suitable enclosures, shielding conduits, connectors, and line filters, as required. External leads shall be shielded to re- duce radio interference by shielded metallic conduit of proper diameter with spherical-seat ball and cone fittings in accord
32、ance with Specification MIL-I- 16165 and Drawing RE-49A501, as applicable. For the foregoing type of ignition, and any other type of ignition which may be used, all electrical connec- tions and wiring shall be waterproof. Measurements and limits specified in Specification MIL-I- 169 10 shall be used
33、 as a guide in designing radio interfer- ence suppression. The arrangement of radio inter- ference suppression and all equipment used for same shall be subject to approval by the bureau or agency concerned. 3.5 Design.- 3.5.1 Except as otherwise specified herein, the boiler shall be designed and man
34、ufactured in accord- ance with the Boiler Construction Code, 3. 5.2 The boiler shall be of the following design and performance characteristics: Pressure design, pounds Pressure operating, Temperature, operating per square inch (psi). psi . burner cut-in . burner cut-off . Temperature, air Boiler ef
35、ficiency Percent carbon dioxide at the boiler smoke outlet Gas temperature at the boiler smoke outlet . 30. . 15. . 175“ F. approxi- mately. . 195“ F. approxi- mately. . 100F. . 75 percent minimum. . 10 percent minimum. . 600F. maximum. 3.5.3 The boiler assembly shall include the following component
36、s: (a) Burner. (b) Forced draft blower. (c) Fuel oil pump. (d) Motors and controllers as required by (e) Automatic ignition and combustion control driven auxiliaries. system, including the following: 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
37、MIL-B-377q8C 45 a 9777906 0232348 7 Length MIL-B- 17748C(SHIPS) Width Height Length Width Height (1) Rotary inverter and ignition transformer as necessary to supply alternating electric current for ignition (on d. c. powered boilers). (2) Thermostatic combustion control. (3) Safety combustion contro
38、l and relay (stack switch). (4) Fuel oil solenoid valve. (5) Control circuit transformer (on a. c. powered boilers). (f) Oil pressure regulating and relief valve. (g) Safety relief valve. (h) Bottom blow-off valve. (i) Pressure and altitude gage and thermom- ( j) Fuel oil pressure gage. (k) Fuel oil
39、 strainer. (.i) Combustion observation window. (m) Cleanout openings and piping connections (n) Fuel oil filter. eter. as necessary. 3. 5.4 The boiler shall be equipped with neces- sary brickwork, insulation, and lagging consisting of a metal jacket over insulation. 1 2 3 4 3. 5. 5 Essentially, the
40、boiler shall be a self- contained and complete unit when connected with electrical, fuel oil, and water supply and return lines to be furnished at the place of installation. All parts of the boiler assembly shall be arranged with respect to each other to permit easy access for servicing or repair an
41、d replacement of parts. Inches Inches Inches Inches Inches Inches Pounds 36 21 36 30 21 51 600 42 24 42 33 24 54 700 48 27 45 39 27 61 850 54 30 48 42 30 64 1000 3. 5.6 The boiler design shall permit normal op- eration of the boiler when subject to inclination to an angle up to 45 degrees in any ire
42、ction. Provisions shall be made for firmly securing the boiler to deck or foundation. 3. 5.7 The boiler shall be of either style A, hori- zontal or style B, vertical (see 6. 1) straight tube de- sign. The weight and physical dimensions of the boiler complete with insulation and lagging and all auxil
43、iaries, accessories, and controls shall be the minimum commensurate with reliable and efficient operation, and shall not exceed the limitations spe- cified in table I: Table 1 - Limitations. I I I I I Style B-vertical I Style A-horizontal I I I I I 1 Size I Overall Overall 3.5.8 The finished diamete
44、rs of tube holes in tube sheet shall not exceed the following: Tube hole Size tube diameter Inches Inches 1 1. 02 1 - 1/4 1.28 1- 1/2 1.53 1-3/4 1. 78 2 2.03 2 - 1/4 2.28 2 - 1/2 2.53 3.5.9 The sharp edge of tube holes shall be taken off on both sides of the plate with a file or other tool. 3.5. 10
45、The boiler shall be of welded construc- tion. Welding shall be in accordance with Standard MIL-STD-278. 3.5. 11 Longitudinal seams of shells shall be welded from inside and outside. Joints shall comply with joint numbers B-2, B-5, B-14, or B-31 of Standard MIL-STD-22. 4 -o Provided by IHSNot for Res
46、aleNo reproduction or networking permitted without license from IHS-,-,-MIL-B - 17748C(SMPS) 3. 5. 12 Plain unfianged tube sheets shall be at- tached to shells and combustion chambers by means of a single ffJ1f groove joint, fillet reinforced weld, similar to joint number T-42 of Standard MIL-STD- 2
47、2, except that the root gap shall not exceed 1/8 inch. The size of the reinforcing fillet shall not be less than the thickness of the thinner of the two parts joined. 3. 5. 13 The following methods shall be used for connecting tubes to the tube sheets: Tubes shall be rolled, beaded, and welded aroun
48、d the edge of the bead. 3. 5. 13. 1 The minimum allowable thickness of noncylindrical shells shall be in accordance with applicable paragraph of the A. S. M. E. Boiler Con- struction Code. 3.6 Auxiliary equipment. - 3.6. 1 Except as otherwise specified herein, all auxiliary equipment shall be furnis
49、hed in accordance with the best commercial practice. 3.6.2 The automatic controls shall be as simple and rugged as practicable and shall be suitable for Marine service. Mercury tube actuated type con- trols are not acceptable. 3.6.3 Particular care shall be taken in design and construction of all control equipment to insure safety of the operating personnel from the danger of electric shock. 3.6.4 Oil burner. - The oil burner shall be of a mechanical pressure atomizing type, capable of smokeles
