1、This specification has been approved by the Bureau of Naval Weapons, Department of the Navy. 1. SCOPE 1.1 Scope. This specification covers one type of silicon carbide- bonded-graphite nozzle insert 2. APPLICABLE DOCUMENTS 2.1 The following documents, of the issue in effect on date of invi- tation fo
2、r bids or request for proposal, form a part of this specification to the extent specified herein. SPECIFICATIONS MIL -1-6866 MIL -R- 2348 I MIL - P- 116 Military Inspection, Penetrant Method of Rocket Motor, Mark 30 Mod I Design and Performance Preservation, Methods of STANDARDS Military MIL -STD -
3、1 05 MIL-STD- 129 MIL - STD - 45 3 Sampling Procedures and Tables For Inspection by Attributes Marking for Shipment and Storage Inspection, Radiographic Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-N-81240 13 7777706 0358885 8 W; i MIL - N- 8i
4、24O ( WP ) DRAWINGS Department of the Navy Bureau of Naval Weapons 2 174529 Insert (When requesting any of the above documents, give the title and complete designation of the item shown above. Copies of this specification and other unclassified specifications, standards and publications required by
5、con- tractors in connection with specific procurement functions may be obtained from the Commanding Officer, Navy Supply Depot (CDS), 5801 Tabor Avenue, Philadelphia, Pennsylvania, 19120. Drawings may be obtained from the Commanding Officer, Naval Ordnance Plant (CTDO), Iroquois Station, Louisville,
6、 Kentucky, 402 14.) 2.2 Other publications. The following documents form a part of this specification to the extent specified herein. Unless otherwise indicated, the issue in effect on date of invitation for bids or request for proposal, shall apply. PUBLICATIONS American Societv for Testing: and Ma
7、terials ASTM C 20-46 Method of Test for Apparent Porosity, Water Absorption, Apparent Specific Gravity, and Bulk Density of Burned Refractory Brick (Application for copies should be addressed to the American Society for Testing and Materials, 1916 Race Street, Philadelphia, Pennsylvania, 19103.) 3,
8、REQUIREMENTS 3.1 Preproduction samples. Unless otherwise specified in the contract or order, preproduction samples of the nozzle insert shall be manufactured using the methods and procedures proposed for the production; The sample shall be tested as specified in Section 4 herein, and is for the purp
9、ose of determining that, prior to starting production, the contractors production methods are capable of yielding items that comply with the technical require- ments of the contract. After satisfactorily passing all the preproduction tests specified herein, no changes in raw materials and processing
10、 of materials for production shall be made without prior written approval of the procuring activity. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-N-L240 13 = 7779906 0358886 T W 3.2 Data requirements. No data is required by this specification
11、or by applicable documents referenced in Section 2 unless specified in the contract or order (see 6.2). 3.3 Materials. The material shall consist of graphite particles of no greater than 420 microns bonded by a silicon .carbide matrix. shall be 2.85 rt 0.10. 3.4.2 Graphite content. The graphite shal
12、l be 18 nor shall these areas be continuous through the thickness of the insert (from internal surface to external surface). 3.4.4 Dimensions. The dimensions shall be as specified on Drawing 2174529. increase by not more than 0.025. free from impurities, chips, voids, and other defects that could ad
13、versely affect its use. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-N-BI240 13 999790b 0358887 I MIL -N- 81240 () 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for inspection. Unless otherwise specified in the contract or purchase order,
14、 the supplier is responsible for the performance of all inspection requirements as specified herein. Except as otherwise specified, the supplier may utilize his own facilities or any commercial laboratory acceptable to the Government. The Government reserves the right to perform any of the inspectio
15、ns set forth in the specification where such inspections are deemed necessary to assure supplies and services conform to prescribed requirements. 4.2 Classification of inspections. Inspection of nozzle inserts shall be classified as follows: a. Preproduction inspection (see 4.4) b. Quality conforman
16、ce inspection (see 4.5) 4.3 Sampling 4.3.1 Preproduction sample. A preproduction sample of six inserts, manufactured in accordance with 3.1, shall be subjected to the preproduction tests detailed in 4.4 at an activity designated by the procuring activity. One shall be crushed for graphite content te
17、st, and up to five shall be installed and fired in accordance with 4.4.1. Further production of inserts by the supplier, prior to the approval of the preproduction sample, shall be at the suppliers risk. 4.3.2 Quality conformance inspection sampling. Except as otherwise specified, the sampling plans
18、 and procedures set forth in MIL-STD-105, level II, shall be used for sampling for specific gravity. For non-destructive tests, 100-percent inspection shall be used. For destructive tests, the sampling plans and procedures set forth in MIL-STD-105, level S-1 shall be used. 4.3.3 Inspection lot. A lo
19、t of inserts shall consist of all items presented for acceptance at one time and produced in a single manufacturing batch under homogeneous conditions of manufacture. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-HIL-N-L2LIO 13 W 79Ob 0358888 3 W -
20、 MIL-N- 81240(WP) 4.4 j. The preproduction sample, after satisfactorily passing the quality conformance inspections detailed in 4.5, shall be subjected to the following tests and examinations. 4.4.1 Throat erosion test. The insert shall be installed in:.a loaded rocket motor and fired in accordance
21、with MIL-R-23481. After firing, the insert shall meet the requirements of 3.4.5. 4.5 Quality conformance inspection. The following quality conformance tests shall be performed on each lot. 4.5.1 Visual examination. Each insert in the lot shall be subjected to visual examination to determine conforma
22、nce with 3.4.4, 3.5 and Section 5, 4.5.2 Raw material. The graphite shall be passed through a U.S. Standard 420 mesh screen prior to use in the nozzle insert. 4.5.3 GraDhite content test a. Preparation of sample. Each of the sample inserts shall be crushed to particle sizes which shall pass through
23、a 10-mesh screen. Using a riffler having eight l/2-inch troughs, a representative sample of not less than 15 grams shall be obtained from each sample insert. Each 15-gram sample shall be crushed to particle sizes which shall be passed through a 100-mesh screen. Each crushed sample shall be placed in
24、 a clean, dry container, labeled to indicate the lot or batch number, material name, manufacturer and date. b. Test procedure. Accurately weigh a platinum crucible to the nearest milligram (mg). Transfer approximately 1,O gram of sample to the platinum crucible. Weigh to nearest milligram. Ignite in
25、 air at 800 degrees Centigrade (C). Maintain the sample at ignition temperature until burning is complete, as indicated by a constant weight. Weigh to nearest milligram. The greatest difference between the extreme values of percent free graphite for the individual samples shall not exceed 10 percent
26、. 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-UIL-N-812LIO 13 W 7797706 0358870 1 W - MIL-N- 8124O(WP) cause for rejection of the individual nozzl
27、e insert. 4.6.2.2 Specific gravity test acceptance. Acceptance shall be based upon an Acceptable Quality Level (AQL) of 1.0 percent as per MIL-STD-105, level II. 4.6.2.3 Destructive. Acceptance shall be based upon an AQL of 4.0 per- cent as per MIL-STD-105, level s-l. 5. PREPARATION FOR DELIVERY 5.1
28、 Preservation, packaging and packing. Unless otherwise specified in the contract or order, minimum requirements for preservation, packaging and packing shall be in accordance with MIL-P-116, method m. 5.2 Marking. Each container shall be marked in accordance with MIL-STD-129. Marking shall include,
29、but not be limited to, the following infor mation: a. Manufacturers name and location b. Insert c. Lot number and date of manufacture d. Number and revision letter of the drawing 6. NOTES 6.1 Intended use. The material purchased in accordance with this specification is intended to be used as nozzle
30、inserts in rocket motors. 6.2 Ordering data. Procurement documents should specify, but not be 7 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-N-BLZgO 13 7777906 035887L 3 MIL- N-8lZ4.O(WP) 3 a“ Q, di O a, k 9 b i cd di O r( 3 a“ Q, di O a, k 65 u i3 cd Q, * O 9 2 a“ Q, * O 9 a, CDCDED amm O00 000 a,a,aJ I kkk 000 mam I 7, k a, -c E d k c a, % PI k O +I en O E( O d .r( -c o 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
