1、*c- - -_ -, -_ I_ - _- - - _- - MIL-C-17774B 73 m 997770b OLL7LIL7 7 - %- MIL-C-l9794B(SHIPS) 11 December 1962 SUPERSEDING 27 October 1959 MIL-C- 19?94A(SHIPS) MILITARY SPECIFICATION CASTABLE MM, REFRACTORY, THERMAL INSULATING 1. SCOPE 1.1 This specification covers thermal insulating refractory cast
2、able mix for use as a back-up insula- tion for refractory furnace linings of boilers. 2. APPLICABLE DOCUMENTS 2.1 The following documents, of the issue in effect on date of invitation for bids or request for pro- posal, form a part of this specification to the extent specified herein: SPECIFICATIONS
3、 FEDERAL UU-S-48 - Sacks, Paper, Shipping. PPP-B-35 - Bags: Textile, Shipping, Burlap, Cotton and Waterproof Laminated. STANDARDS MILITARY MIL-STD-105 - Sampling Procedures and Tables for Inspection by Attributes. MIL-STD-129 - Marking for Shipment and Storage. (Copies of specifications, standards,
4、drawings, and publications required by suppliers in connection with specific procurement functions should be obtained from the procuring activity or as directed by the contracting officer.) 2.2 Other publications. - The following document forms a part of this specification to the extent specified he
5、rein. Unless otherwise indicated, the issue in effect on date of invitation for bids or request for proposal shall apply: OFFICIAL CLASSIFICATION COMMITTEE Uniform Freight Classification Rules. (Application for copies should be addressed to the Official Classification Committee, 1 Park Avenue at 33r
6、d Street, New York 16, N.Y.) 3. REQUIREMENTS 3.1 Material. - The castable refractory shall be composed of a mixture of heat-resistant materials and a bond material. It shall mix readily with water and shall be of such consistency when mixed with water that it can be cast into a sound wall reasonably
7、 free of voids. 3.2 Time for air set. - The length of time for air setting shall not be greater than 24 hours. At the end of this period, the mix shall support its own weight and maintain its originally cast shape (see 4.4. i). 3.3. Density. - The density of the castable refractory shall not exceed
8、45 pounds per cubic foot after being heat soaked at 2,000“F. for 5 hours (see 4.4.2). 3.4 Permanent linear change. - The permanent linear change shall not exceed 3. O percent shrinkage after being heat soaked at 2,000“F. for 5 hours (see 4.4.3). fusion or softening upon completion of the test specif
9、ied in 4.4.4 and shall retain its cast shape without crumbling when removed from the panel assembly. 3.5 Refractoriness. - The castable refractory shall be in satisfactory condition without evidence of I FSC 9350 I THIS DOCUMENT CONTAINS y PAGES. - - - Provided by IHSNot for ResaleNo reproduction or
10、 networking permitted without license from IHS-,-,-MIL-C-l9794B(SHPS) 3.6 T-aI conductance. - The thermal conductance of the mix shali be such that the temperature drop through and block cast from the mix shall be not less than 1,800F. when the hot face of the block is maintained at 2,500F. (see 4.4
11、.4). 3.7 Workmanship. - Workmanship shall be first class in every respect. 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for inspection. - Unless otherwise specified in the contract or purchase order, the supplier is responsible for the performance of all inspection requirements as specified he
12、rein. Except as otherwise specified, the supplier may utilize his own facilities or any commercial laboratory satisfac- tory to the Government. The Government reserves the right to perform any of the inspections set forth in the specification where such inspections are deemed necessary to assure sup
13、plies and services conform to prescribed requirements. 4.2 SampIing for quality conformance inspection. - Sampling for inspection shall be performed in ac- cordancewe provisions set forth in MIL-STD-105, except where otherwise indicated. For purposes of sampIing, an inspection lot for quality confor
14、mance inspection shall consist of all material offered for delivery at one time. 4.3 inspection of the castable mix. - 4.3.1 Examination of the castable mix. - Examination of the castable mix shall be made in accordance with the classification of defects, inspection levels and acceptable quality lev
15、els (AQLs) set forth below. The lot size, for purpose of determining the sample size in accordance with MIL-STD-105, shall be ex- pressed in units of filled containers of castable refractory mix for examination in 4.3.1.1, 4.3.1.2 and 4.3.1.3. 4.3.1.1 Examination of castable mix container for defect
16、s in appearance, workmanship, closures and markings.- The sample unit for this examination shall be one filled container. Examine Defect Appearance and workmanship Not type or size specified. Evidence of sifting or leaking of contents. Bag laminations not as specified. Scuff marks, torn or punctured
17、. End closure not as specified. Omitted, illegible, incorrect, incomplete or not in accordance with contract requirements. Closures Markings 4.3.1.2 Examination of castable mix container for defects in appearance of refractory castable mix. - The sample unit for this examination shall be one filled
18、container. Examine Defect Appearance Material not as specified. Presence of foreign material. Presence of large particles, lumps or caked material. 4.3.1.3 Examination of castable mix for defects in net contents. The sample unit for this examination shall be one filled container. The average net con
19、tents shall be not less than the specified or indicated quantity. No less than five sample units shall be drawn for this examination. 4.3.1.4 inspection levels and acceptable quality levels (AQLs) for examinations. - The inspection levels for determining the sample size and acceptable quality levels
20、 (AQLs) expressed in defects per 100 units shall be as follows: Examination Paragraph inspection Level 4.3.1.1 I 4.3.1.2 L- 6 4.3.1.3 L-4 2 AQL 2.5 2.5 - - I e I h Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-C-l9794B(SAIPS) 4.3.2 Testing of t
21、he castable mix. - The castable mix shall be tested for the applicable characteristics as indicated in table I for each lot presented for examination. The sample unit shall be 15 pounds of the refractory castable mix. The inspection level for determining sample size shall be L-2 except that no less
22、than five sample units shall be randomly selected throughout the lot. No more than one sample shall be drawn from any one container. The test sample shall consist of a 75-pound composite of the sample units. Two or more determinations, as applicable, shall be performed on the composite. There shall
23、be no evi- dence of failure to meet the specified requirements. Table I - Instruc?ions for testing. Spec if icat ion Ref er ence I Number Determinations I per (composite) I Method Test Require- 1 ment Character istics Airsett ing 3.2 4.4.1 2 Density 3.3 4.4.2 Avgof 2 Permanent linear change 3.4 4.4.
24、3 Avgof 2 Refractor ines s 3.5 4.4.4 2 Fusion Softening Crumbling Thermal conductance 3.6 4.4.4 Avgof 2 Results Reported As Pass or Fail/ Numerical1 To Nearest-/ - 0.11b. percu. ft. 0.1 percent l/If failure is indicated, report either description of failure or numerical point of failure. ZTest repor
25、ts shail include all values on which average results are based. 4.4 Tests.- 4.4.1 Time for air set. - The test material shall be thoroughly mixed with water to the consistency of stiff concrete. This mixture shall then be poured into 9 by 4-1/2 by 2-1/2-inch steel molds and shall be placed at once i
26、n a chamber having constant atmosphere of 90F. and 90 percent humidity. At the end of 24 hours the mold shall be removed. 4.4.2 Density. - The test bricks prepared as specified in 4.4.1 shall be returned to the constant humidity chamber for an additional 24 hours of curing. The test bricks shall the
27、n be removed and oven dried for 12 hours at temperature of 220F. Then the test bricks shall be measured. The tes? bricks shall be subjected to a 5 hour heat soak at 2,000“F. and then allowed to cool in the closed furnace to room temperature. The test bricks shall then be weighed. The density shall b
28、e computed from the oven dry volume and the weight after firing at 2,000“F. 4.4.3 Permanent linear change.- The permanent linear change shall be computed from the molded length of the test bricks prepared as specified in 4.4.1 and the fired length of these bricks after being tested as specified in 4
29、.4.2. 4.4.4 Refractoriness and thermal conductance. - The test material shall be thoroughly mixed with water to the consistency of stiff concrete and cast into a block 18 by 18 by 3-1/2 inches. The block shall be allowed to remain in the mold for 24 hours at atmospheric temperatures and then removed
30、 from the mold and allowed to air dry for an additional 24 hours. The test block shall be hilt into a panel. The panel shall be composed of the 3-1/2-inch thick block faced with 2-1/2 inches of firebrick and backed with a 1/8 inch thick steel plate. The firebrick face of the panel shall be exposed t
31、o the furnace atmosphere. The interface of the block and the firebrick shall be maintained at a temperature of 2,500“F. for 24 hours. Then the temperature drop through the cast block shall be determined. The panel shall be allowed to cool to room temperature. Then the test block shall be examined fo
32、r evidence of fusion, softening or crumbling. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-C-l9794B(SHIPS) 5 PREPARATION FOR DELIVERY 5.1 Packing. - 5.1.1 Level A. - Castable refractory shall be packed in 50 pound quantities in multi-wall ship
33、ping sacks construction number 5X or textile laminated shipping bags conforming to UU-S-48 and PPP-B-35, respectively. The specific container selected shall incorporate a liner or ply to provide required mois- ture protection. 5.1.2 Level B. - Castable refractory shall be packed in 50 pound quantiti
34、es in multi-wall shipping sacks construction number 1W or textile laminated shipping bags conforming to UU-S-48 and PPP-B-35, reBpectively. The specific container selected shall incorporate a liner or ply to provide required mois- ture protection. 5.1.3 Level C. - Castable refractory shall be packed
35、 in a manner to insure carrier acceptance and safe delivery to destination at the lowest applicable rate. Containers shall comply with the Uniform Freight Classification Rules or other carrier regulations applicable to the mode of transportation. shipment shall be in accordance with MIL-STD-129. 5.2
36、 Marking.- In addition to any special marking required in the contract or order, marking for 6. NTES 6.1 Ordering data. - Procurement documents should specify the following: (a) Title, number, and date of this specification. (b) Applicable level of packing required (see 5.1). Notice. - When Governme
37、nt drawings, specifications, or other data are used for any purpose other than in connection with a definitely related Government procurement operation, the United States Govern- ment thereby incurs no responsibility nor any obligation whatsoever; and the fact that the Government may have formulated
38、, furnished, or in any way supplied the said drawings, specifications, or other data is not to be regarded by implication or otherwise as in any manner licensing the holder or any other person or corporation, or conveying any rights or permission to manufacture, use, or sell any patented invention that may in any way be related thereto. 4 Preparing activity: Navy - Bureau of Ships (Project 9350-N013Sh) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
