1、pzq A-A-59375 27June2000 SUPERSEDING 28 October 1986 MIL-F- 8025 SA COMMERCIAL ITEM DESCRIPTION FURNACES, HEAT-TREATING, ELECTRIC, NATURAL ATMOSPHERE, BOX TYPE The General Services Administration has authorized the use of this commercial item description for all federal agencies. 1. SCOPE. This comm
2、ercial item description (CID) covers electric box type furnaces intended for use in heat-treating shops for hardening, tempering, normalizing, and annealing metal parts in a natural atmosphere. Furnaces covered by this CID are not intended for atmosphere control use. 2. CLASSIFICATION. The furnaces
3、shall be of the following types, styles, classes, and sizes. The type, style, class, and size to be furnished shall be as specified (see 7.2(b). The chamber depth for the type I furnace shall be as specified (see 7.2(c). Type I - Single chamber (style A or style B) Type II - Double chamber (style A
4、lower chamber and style B upper chamber) Style A - Forced air convection design Class 1 - 1200 OF to 1250 OF maximum operating temperature Class 2 - 1400 OF maximum operating temperature Style B - Radiation design Class 2 - 1400 OF maximum operating temperature Class 3 - 2000 OF maximum operating te
5、mperature Class 4 - 2200 OF to 2300 OF maximum operating temperature Class 5 - 2750 OF maximum operating temperature Size and depth - The chamber width, height, and depth are shown in tables I through III. Beneficial comments, recommendations, additions, deletions, clarifications, etc., and any data
6、 which may improve this document should be sent to: Defense Supply Center Richmond, ATTN: DSCR-VBD, 8000 Jefferson Davis Highway, Richmond, VA 23297-5610. AMSC NIA FSC 3424 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Provided by IHSNot for ResaleNo reproduction
7、or networking permitted without license from IHS-,-,-A-A-59375 TABLE II. Sizes of type I, style B furnaces. 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-A-A-59375 Size o1 TABLE II. Sizes of type I, style B furnaces (continued). Lower furnace Upp
8、er furnace Chamber dimensions, Chamber dimensions, Width Height Depth Width Height Depth Style Class inches Style Class inches 2 12 12 11 3 12 12 12 TABLE III. Sizes of type II furnaces. 121 12 I 12 I 17 I 2 12 12 23 2 12 12 29 2 18 18 24 A 2 18 18 36 B 11 19 I 12 I 19 11 10 I 10 I 24 1 12 12 36 1 1
9、9 12 19 131 12 I 12 I 18 I 3 12 12 24 3 12 12 30 10 10 24 I I 4 12 12 36 4 19 12 19 3. SALIENT CHARACTERISTICS 3.1 General requirements. The furnace shall be new and one of the manufacturers current models capable of operation in accordance with the requirements herein. All parts subject to wear, br
10、eakage, or distortion shall be accessible for adjustment, replacement, and repair. The furnace shall be a box design having electrical heating elements, a hearth to support the load, and a single opening in the end of the chamber for loading and unloading on a horizontal plane. 3.1.1 Furnace type. T
11、he type I furnace shall have a single chamber of either a style A forced air convection design or a style B radiation design. The type II furnace shall have a double chamber (overhnder) with a style A lower chamber and a style B upper chamber. 3 Provided by IHSNot for ResaleNo reproduction or networ
12、king permitted without license from IHS-,-,-A-A-59375 3.1.2 Furnace stvle. The style A furnace shall use forced air convection to heat the load. Air shall be heated in an area separated from the load and blown into the chamber by one or more fans. The load shall not be exposed to radiant heat from t
13、he electrical heating elements. The style B furnace shall use radiation to heat the load by direct exposure to the electrical heating elements. 3.2 Components. All the furnaces shall include, as a minimum, the following components: 3.2.1 Frame. The furnace shall have a structural frame that shall pr
14、ovide stable support for the chamber, hearth, and maximum rated load. A floor-mounted furnace shall have provisions for being lifted by a forklift. 3.2.2 Shell. The outer shell of the furnace shall be constructed of reinforced sheet steel and have welded or riveted joints to provide a rigid structur
15、e. 3.2.3 Hearth. Unless otherwise specified (see 7.2(d), the hearth shall be constructed of heat- conducting material considered by the manufacturer as standard. The hearth shall be capable of supporting rated loads at the furnace maximum operating temperature without permanent distortion. If requir
16、ed, rollers or slide rails shall be provided for moving the load in and out of the chamber as specified (see 7.2(e). If required, the furnace shall be provided with the number and arrangement of removable shelves as specified (see 7.2(f). 3.2.4 Lining. The furnace chamber and door lining shall be ra
17、ted for the furnace maximum operating temperature and shall have insulating properties that maintain the furnace exterior surface temperature at or below the temperature shown in table IV. 3.2.5 Door. The furnace shall have a door-operated interlock switch that turns off the power to the heating ele
18、ments when the door is opened. The door of a class 1 or 2 furnace shall be mounted on hinges and swing open. The door of a class 3,4, or 5 furnace shall open by being lifted vertically either by manual means with a suitable counterweight(s) or by a power-operated system as specified (see 7.2(g). The
19、 door mechanism shall move the door away from the face of the furnace a sufficient distance to prevent damage to the chamber perimeter seal or to the lining during lifting and lowering. The door hot side shall face away from the operator at all times during lifting and lowering. 3.2.6 Temperature co
20、ntroller. Unless otherwise specified (see 7.2(h), the furnace shall have a microprocessor-based programmable temperature controller that meets the requirements of sections 5-3 and 5-18.2 of National Fire Protection Association (NFPA) 86, “Standard for Ovens and Furnaces“ (DoD adopted). The temperatu
21、re controller shall maintain the furnace chambers temperature at the control thermocouple within k 2 OF of the set temperature. If required, ramp and soak period software programs for process temperature control shall be provided as specified (see 7.2(i). The temperature controller shall have an ext
22、ernal dual 120-volt, single-phase, 60- hertz outlet for powering a process data recorder or other process monitor. 3.2.7 Excess temperature controller. Unless otherwise specified (see 7.2j), an excess temperature controller independent of the temperature controller shall be provided. The excess temp
23、erature controller shall automatically turn off the heating elements when the chamber temperature rises above the set temperature by an incremental temperature selectable within a range of 50 OF to 100 OF. 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IH
24、S-,-,-A-A-59375 Style 3.2.8 Electrical svstem. Unless otherwise specified (see 7.2(k), the electrical system shall conform to the NFPA 70, “National Electrical Code“ (DoD adopted), and NFPA 86 sections 4-6 and 5-18. The furnace shall be wired for operation from a 230- or 460-volt, 3-phase, 60-hertz
25、circuit as specified (see 7.2(1). Maximum rated Maximum surface Class temperature (MRT), OF temperature at MRT, OF 3.2.9 Optional accessories. Optional accessories shall be provided as specified (see 7.2(m). 1 2 2 3 4 5 A B 3.3 Performance. Unless otherwise specified (see 7.2(n), the furnace shall b
26、e capable of operating continuously with the maximum rated load at any set temperature within the operating range considered by the manufacturer as standard. 1200-1250 Ambient + 60 1400 Ambient + 80 1400 Ambient + 80 2000 Ambient + 140 2200-2300 Ambient + 160 2750 Ambient + 200 3.3.1 Exterior surfac
27、e temperature. Unless otherwise specified (see 7.2(0), the furnace exterior allowable maximum surface temperature is shown in table IV when operating at the chamber maximum rated temperature. Style A B TABLE IV. Furnace exterior surface temperatures. Chamber temperature, Recovery rate, OF pounds/squ
28、are foothour Class 1 1200 60 2 1400 60 2 1400 60 3 2000 60 4 2150 50 5 2150 50 3.3.2 Recovery rate and heating capacity. The furnace shall have a recovery rate for not less than the weight of iron or steel per square foot of hearth area per hour heated to the temperature shown in table V. The furnac
29、e shall have a heating capacity of not less than the weight of iron or steel per square foot of hearth area heated to the temperature shown in table VI. TABLE V. Recovery rate. 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-A-A-59375 Style A TABLE
30、 VI. Heating capacity. Chamber temperature, Heat capacity, “F pounds/square foot Class 1 1200 100 2 1400 100 2 1400 100 IB 3 2000 100 4 2300 80 5 3.4 Furnace dimensions and weight. If required, the maximum exterior dimensions (length, width, and height) and weight shall not exceed the restrictions s
31、pecified (see 7.2(p). 2750 60 3.5 Safety and health requirements. The furnace shall be designed and manufactured in accordance with NFPA 86. If required to process volatile substances, combustible materials, or finished or oil-coated metal parts, the furnace shall meet the requirements of NFPA 86, c
32、lass A ovens as specified (see 7.2(q). Otherwise, the furnace shall meet the requirements of NFPA 86, class B ovens. The manufacturer shall ensure that the furnace and all equipment and accessories used on the furnace shall be in compliance with Occupational Safety and Health Administrations (OSHA)
33、Title 29 of the Code of Federal Regulations (CFR), Part 1910, “Occupational Safety and Health Standards“. If a conflict arises between the NFPA and OSHA standards, the OSHA standards shall apply. 3.6 System of units. The U.S. Customary System of Units (US) or the International System of Units (SI) s
34、hall be used to graduate measuring and indicating devices. When only one system of graduation is acceptable, the particular graduation required shall be as specified (see 7.2(r). Regardless of the measurement system used, all measuring and indicating devices on the furnace shall be graduated in the
35、same system. When specified (see 7.2(s), measuring and indicating devices shall be graduated in both the US and SI system of measurements. 3.7 Nameplate. A nameplate shall be securely attached to the furnace. Unless otherwise specified (see 7.2(t), the nameplate shall contain the following informati
36、on: a. b. d. e. f. g. h. C. 1. Nomenclature. Manufacturers name. Serial number. Furnace model designation. Power input (volts, total amperes, phase, Short-circuitover-current rating. Contract number or order number. National stock number. Date of manufacture. and frequency). 6 Provided by IHSNot for
37、 ResaleNo reproduction or networking permitted without license from IHS-,-,-A-A-59375 3.8 Lubrication plate or chart. When specified (see 7.2(u), a lubrication plate or chart shall be attached to the furnace. The information provided on the plate or chart shall include: a. Points of lubricant applic
38、ation. b. Servicing interval. c. Type of lubricant(s) with SAE number or lubricant identifier. 4. REGULATORY REQUIREMENTS 4.1 Recovered materials. The offerorkontractor is encouraged to use recovered materials to the maximum extent practicable, in accordance with paragraph 23.403 of the Federal Acqu
39、isition Regulation (FAR). 4.2 Environmental protection. The item shall meet all applicable Environmental Protection Agency (EPA) restrictions in effect on the date of the contract. These regulations apply to the emission of materials hazardous to the environment or the users health and shall be adhe
40、red to during the manufacturing, service, transportation, storage, and operationhse of the item. 5. PRODUCT CONFORMANCE PROVISIONS 5.1 Product conformance. The products provided shall meet the salient characteristics of this commercial item description, conform to the producers own drawings, specifi
41、cations, standards, and quality assurance practices, and be the same product offered for sale in the commercial marketplace. The government reserves the right to require proof of such conformance. 5.2 Inspection. The furnace shall be inspected to determine compliance with all requirements specified
42、in this CID. 5.3 Testing. Unless otherwise specified (see 7.2(v), the furnace shall be tested in accordance with sections 5.3.1 through 5.3.6. 5.3.1 Test setup and conditions. Unless otherwise specified (see 7.2(w), the manufacturer shall be responsible for supplying all tooling and material(s) and
43、shall conduct all tests required by the Government. The manufacturer shall provide test instruments and equipment with calibration traceable to the National Institute of Standards and Technology (NIST) and shall provide certification of calibration as specified (see 7.2(x). Unless otherwise specifie
44、d (see 7.2(y), the furnace shall be tested at an ambient temperature of 80 OF k 20 OF. 5.3.2 Operational test. The furnace shall be operated in accordance with the manufacturers standard operational procedures for furnace startup and refractory cure. The furnace shall be operated at the chamber maxi
45、mum rated temperature for not less than 8 hours. Proper operation of all controls and features shall be verified during the trial period. 7 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-A-A-59375 5.3.3 Surface temperature test. The chamber shall be
46、 stabilized at its maximum operating temperature, and the exterior surface temperatures of the furnace and door shall be measured at random locations. The exterior surfaces shall not exceed the temperature shown in table IV for the furnace provided. 5.3.4 Performance test. With the chamber temperatu
47、re stabilized at the temperature shown in table V, the furnace shall be loaded with an ambient-temperature batch of iron or steel equivalent to the hourly recovery weight for the style and class of furnace. A temperature survey shall be recorded in accordance with Society of Automotive EngineerdAero
48、space Material Specification SAE/AMS 2750, “Pyrometry“ (DoD adopted), during the recovery cycle, and at the end of 1 hour the temperature shall have recovered within +lo OF of the initial temperature. From the time the recovery cycle is initiated until thermal equilibrium is reached, no temperature
49、reading shall exceed the target recovery temperature by more than 10 OF. The results of the test shall be compared with the requirements specified in paragraphs 3.3 through 3.3.2. 5.3.5 Temperature uniformity. After the load and chamber in section 5.3.4 performance test have reached thermal equilibrium, a temperature survey shall be taken every 5 minutes for 30 minutes in accordance with SAE/AMS 2750. The temperatu
