1、MIL-L-18618A 68 777770b OLL7271 7 9 &58q&TD MIL-L-l8618A(OS) 5 January 1976 SUPERCEDING MIL-L-18618 (Nord) 2 June 1955 MILITARY SPECIFICATION LEAD CARBONATE, BASIC, DRY (FOR ORDNANCE USE) This specification is approved for use by all departments and agencies of the Department of Defense. 1, SCOPE 1.
2、1 Scope. This specification covers basic lead carbonate for use in propellant powders. 2. APPLICABLE DOCUMENTS *2.1 The following documents of the issues in effect on date of In the event of conflict invitation for bids or request for proposals form a part of this speci- fication to the extent speci
3、fied herein. between this specfication and other documents referenced herein, requirements of this specification shall apply. SPECIFICATIONS Mili t ary MIL-P-17449 Powder, Propellant, Cordite N STANDARDS Military MIL-STD-129 Marking of Shipment and Storage (Copies of specifications and standards req
4、uired by suppliers in connection with specific procurement functions should be obtained from the procuring activity or as directed by the contracting officer.) . o Licensed by Information Handling ServicesMIL-L-1bLA 68 m 777770b 0117272 7 m MI L-L- 18 6 18A (OS) *2.2 Other publications. The followin
5、g documents form a part of this specification to the extent specified herein. between this specification and other documents referenced herein, the requirements of this specification shall apply. In the event of conflict American Society for Testing and Materials (ASTM) D 185 D 280 D 301 D 1301 Coar
6、se Particles in Pigments, Pastes, and Paints, Test for. Hygroscopic Moisture and Other Matter Volatile Under the Test Conditions in Pigments, Test for Soluble Nitrocellulose, Test for Chemical Analysis of White Lead Pigments, Standard Methods for (Copies are obtainable from the American Society for
7、Testing and Materials, 1916 Raca Street, Philadelphia, Pa. 19103.) 3. REQUIREMENTS 3.1 Material. The material shall be a high-grade basic carbonate white lead and shall contain no more than traces of impurities incident to well controlled manufacture of this material. Requirements Minimum Impurities
8、 62% Lead carbonate Total lead (calculated as Pb) 80% Moisture - Maximum 0.5% 69 % 0.7% 3.1.2 Physical properties. All primary samples shall conform to the fallowing physical requirements: 2 Licensed by Information Handling ServicesRequirement s Minimum Maximum 5 microns Average particle size - Perc
9、ent coarse particles - 0.5% 3.1.3 pH value. When tested as specified in 4.3.2, all primary samples shall have a pH value between 5.5 and 7.0. 3.1.4 Compatibility test. When tested as specified in 4.3.4, the stability end point for the control shall not differ by more than 10 minutes from the stabili
10、ty end point for any of the primary samples of basic lead carbonate mixed with propellant. 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
11、as specified herein. as otherwise specified in the contract or order, the supplier may use his own or any other facilities suitable for the performance of the inspection requirements specified herein, unless disapproved by the Government. inspections set forth in the specification where such inspect
12、ions are deemed necessary to assure supplies and services conform to prescribed requirements. Except The Government reserves the right to perform any of the 4.2 Sampling. 4.2.3 - Lot. A lot shall consist of 5,000 pounds or less of material manufactured as part of one batch or under uniform process c
13、onditions. 4.2.2 Samples. A minimum of five containers in the lot shall be selected in a random manner so as to be representative of the lot, From each selected container, a primary sample of 1-1/2 pounds shall be removed by means of a scoop. into 3 subsamples of 8 ounces each. The first and second
14、subsamples from each container shall be placed in separate rubber stoppered bottles and labeled to show the name of the material, manufacturer, plant, con- tract or order number, lot number, and the identification of the con- tainer from which it was taken. The remaining 8-ounce subsamples shall be
15、thoroughly mixed together and separated into 2 approximately equal composite samples, Each composite sample shall be placed in a rubber Each sample shall then be subdivided 3 -. Licensed by Information Handling ServicesMIL-L-LbLBA b 999970b OLL7274 2 MIL-L- 186 18A (OS ) stoppered bottle and labeled
16、 to show the name of the material, manufac- turer, plant, contract or order number, number of pounds in the lot, and lot number. The five bottles containing the first subsamples from each container and one bottle of the composite sample shall be forwarded to the Commanding Officer, Naval Ordnance St
17、ation, Indian Head, Md., for analysis, Each of the forwarded primary samples shall be for use in testing conformity to the requirements for physical properties, pH, and compatibility. chemical analysis. The remaining five bottles containing the second subsamples from each container and the other bot
18、tle containing the composite sample shall be retained for possible future use in case any of the samples tested should fail to meet the requirments of this speci- f ication. The forwarded composite sample shall be for use in the 4.3 Test procedures. *4.3.1 Chemical composition. Analysis for chemical
19、 composition shall be carried out on the Composite sample in accordance with the following. 3r4.3.1.1 Insoluble impurities. Insoluble impurities shall be deter- mined in accordance with ASTM D 1301. *4.3.1.2 Total lead. Total lead shall be determined in accordance with ASTM D 1301, using the factor
20、0.641 for converting lead chromate to lead. *4.3.1,3 Lead carbonate. Lead carbonate shall be determined in accordance with ASTM D 1301, using the evolution method for determining con. *4.3.1.4 Moisture. Moisture shall be determined in accordance with ASTM D 280. 4.3.2 pH value. Prepare a quantity of
21、 carbon dioxide-free water by boiling distilled water in a 1-liter flask for 15 minutes. flask with an “Ascarite“ (or similar CO2 absorbent material) guard tube and cool to 25“ C. Check the pH of the water at 25“ f 1“ C to determine that its value lies between 6.0 and 70. Transfer 10 * 0.01 grams of
22、 a primary sample of the basic lead carbonate to a 250-milliliter (mi) flask equipped with a ground-glass stopper. stopper the flask, and shake for 1 minute Close the Add 100 ml of the prepared water, Allow the flask and contents 4 Licensed by Information Handling ServicesMIL-L-LbL&A 68 7799706 OLL7
23、275 Y W MIL-L-l8618A( OS) to stand for 1 hour, with occasional swirling, at 25“ k 1“ C. Allow the sample to settle. Determine the pH of the liquid at 25“ 1: 1 C by means of a calibrated potentiometer equipped with a glass electrode and a saturated calomel reference elec- trode, sample submitted as r
24、epresentative of the lot. Decant a portion of the supernatant liquid. Repeat or concurrently perform this procedure for each primary 4.3.3 Physcial properties. 4.3.3.1 Average particle size. The average particle size shall be determined separately on each primary sample using the Fisher Sub-Sieve Si
25、zer. shall be used. instructions supplied with the instrument. A sample of 6.14 t 0.01 grams (approximately 1 ml by volume) All operations shall be performed in accordance with the *4.3.3.2 Percent coarse particles. Each primary sample shall be tested as described in ASTM D 185, using a No. 325 U. S
26、. Standard sieve. *4.3.4 Compatibility test. Each primary sample shall be tested separately, but the tests can be run concurrently with a single control standard if facilities permit. A ground sample of Cordite N propellant powder, which has met the requirements of MIL-P-17449 shall be mixed thoroug
27、hly with 10 percent of its weight of the primary sample. mixture shall then be subjected to the stability test described in ASTM D 301, using a temperature of 120“ C instead of 134.5 C, A control sample of the Cordite N propellant powder mixed thoroughly with 10 percent of its weight of the standard
28、 lead carbonate (Lot IH STD 1 previously tested at the Naval Ordnance Station, Indian Head, Md, and found satis- factory for propellant use), shall be tested at the same time. This 5. PREPARATION FOR DELIVERY 5.1 Packaging, Unless otherwise specified in the contract or pur- chase order, basic lead c
29、arbonate shall be packaged in 50-pound con- tainers conforming to standard commercial practice for the pigment “basic carbonate white lead. “ 5.2 Marking. Unless otherwise specified, each container shall be plainly marked with the following information completed: 5 Licensed by Information Handling S
30、ervicesMIL-L- 186 18A (OS ) Mat er i al Specification Stock No. Qum ti ty Contractor Manufacturer Contract No. Gross Weight Date Lot No. In addition to the foregoing, shipments shall be marked in accordance with the requirements of MIL-STD-129. 6. NOTES *6.1 Ordering data. Procurement documents shou
31、ld specify the title, number, and date of this specification. 6,2 Material. Under 3.1, the material is described chemically as basic lead carbonate with a lead carbonate content of 62 to 69 percent. The remainder (other than impurities and moisture) is generally all lead hydroxide or various proport
32、ions of lead hydroxide and anhydrous lead oxide combined in the compound. Thus, the material “basic lead car- bonate“ covered by this specification is high grade commercial “white lead“ with a lead carbonate content and ratio of lead carbonate to lead hydroxide complying with the requirements of 3.1
33、. 6.3 Compatibility test. The compatibility test described in 4.3.4 is intended to determine whether any undesirable interaction occurs between the material and the propellant powder. that high grade commercial pigment “basic carbonate white lead“ will readily pass this test. bility tests will be co
34、nducted at Government laboratories. fnformation regarding testing of samples for conformance to the compatibility require- ment prior to submission of bids may be obtained from the Commanding Officer, Naval Ordnance Station, Indian Head, Md. 20640. Previous tests have indicated Prime manufacturers a
35、re advised that compati- 6 Licensed by Information Handling Services- - MIL-L-L8bLA b 77777Ob OLL7277 W *6.4 The margins of this specification are marked with asterisks to indicate where changes (additions, modifications, corrections, delections) from the previous issue were made. This was done as a
36、 convenience only and the Government assumes no liability whatsoever for any inaccuracies in these notations. Bidders and contractors are cautioned to evaluate the requirements of this document based on the entire content irrespec- tive of the marginal notations and relationship to the last previous issue. Custodian : Navy - OS ri US. GOVERNMENT PRINTING OFFICE: V76-603-766:254 Preparing activity: (Project No. 6810-N077) Navy - OS 7 Licensed by Information Handling Services
