1、MIL-PRF-7254G 15 December 1997 SUPERSEDING MIL-P-7254F 30 April 1970 PERFORMANCE SPECIFICATION PROPELLANT, NITRIC ACID This specification is approved for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification covers the requirements for four types of
2、 nitric acid propellant. 1.2 Classification. The nitric acid will be of the following types as specified (6.2): 1.2.1 Types. The types of nitric acid are as follows: Type IIIA - Nominal 14 percent NO2 content plus corrosion inhibitor Type IIIB - Nominal 14 percent NOz content, lower solids content,
3、plus corrosion inhibitor Type IIILS - Limited storage propellant with nominal 14 percent NO2 content, lower solids content, plus corrosion inhibitor, and limited iron content Type IV - High density propellant with nominal 44 percent NO2 content, lower solids content, plus corrosion inhibitor, and li
4、mited iron content 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed in this section are specified in sections 3 and 4 of this specification. This section does not include documents in other sections of this specification or recommended for additional information or as examples. While every
5、effort has been made to ensure the completeness of this list, document users are cautioned that they Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to SA- ALC/SFSP, 1014 Billy Mitchell Blvd/STE 1,
6、Kelly AFB TX 78241-5603, by using the Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter. AMSC N/A FSC 9135 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Provided by IHSNot for ResaleNo reproduction or n
7、etworking permitted without license from IHS-,-,-m 0b 2047377 927 MIL-PRF-7254G must meet all specified requirements documents cited in sections 3 and 4 of this specification, whether or not they are listed. 2.2 Government documents. 2.2.1 Specifications, standards, and handbooks. The following spec
8、ifications form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those listed in the issue of the Department of Defense Index of Specifications and Standards (DoDISS) and supplement thereto, cited in the solicitation (see 6.2). S P
9、ECI FICAT IONS DEPARTMENT OF DEFENSE MIL-PRF-27401 - Propellant, Pressurizing Agent, Nitrogen (Unless otherwise indicated, copies of the above specifications are available from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia.PA 19111-5094). 2.3 Non-Government p
10、ublications. The following documents form a part of this document to the extent specified herein. Unless otherwise specified, the issues of the documents which are DoD adopted are those listed in the issue of the DoDISS cited in the solicitation. Unless otherwise specified, the issues of documents n
11、ot listed in the DoDISS are the issues of the documents cited in the solicitation (see 6.2). AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM) ASTM D 1068 - Test Methods for Iron in Water (DoD adopted) ASTM E 29 - Practice for Using Significant Digits in Test Data to Determine Conformance with Speci
12、fications (DoD adopted) (Application for copies should be addressed to the American Society for Testing and Materials, 100 Barr Harbor Drive, West Conshohocken PA 19428-2959 2.4 Order of precedence. In the event of a conflict between the text of this document and the references cited herein, the tex
13、t of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 3. REQUIREMENTS 3.1 Chemical composition and physical properties. The chemical composition and physical properties of the propellants shal
14、l conform to Table I. 3.2 Limiting values. The following applies to all specified limits in this specification: For purposes of determining conformance with these requirements, an observed value or a calculated value shall be rounded off “to the nearest unit“ in the last right-hand digit used in exp
15、ressing the specification limit according to the rounding-off method of ASTM Practice E 29 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. Composition “03, percent by weight NO*, percent by weight HF, percent by weight H20, percent by weight Fe20
16、3, percent by weight Solids , percent by weight, as nitrates Specific Gravity, 15.6“C/15.6“C 0 90b 2047378 863 Type IIIA Type IIIB Type IIILS Type IV Test Para 81.6 - 84.9 81.7 - 84.9 83.7 - 86.4 52.7 - 57.4 4.4.9 14 f 1 14 ? 1 14 $: 1 44 k 2 4.4.3 0.7 f 0.1 0.7 k 0.1 4.4.4 0.7 k 0.1 0.7 * 0.1 0.5 m
17、ax 4.4.8 1.5 - 2.5 1.5 - 2.5 0.5 max 4.4.7 not not 0.0015 max 0.002 max specified specified 0.10 max 0.04 max 0.04 max 0.04 max 4.4.6 4.4.5 1.564 min 1.564 min 1.572 min 1.642 min 1.575 max 1.575 max 1.582 max 1.652 max MIL-PRF-7254G for Using Significant Digits in Test Data to Determine Conformance
18、 with Specifications. 3.3 Qualitative. The propellant shall be a single phase liquid (6.4) when examined visually by transmitted light, and the IRFNA spectrum resulting from the water analysis (4.4.8 and Figure 2) shall contain the 1440 nm peak which identifies the presence of nitric acid. TABLE I.
19、Chemical composition and physical properties. 4. VERIFICATION 4.1 Classification of inspections. The inspections shall be classified as quality conformance inspections. 4.2 Quality conformance inspection. The quality conformance inspection shall consist of the following: a. Individual tests . 4.2.1
20、b. Sampling tests 4.2.2 4.2.1 Individual tests. The propellant shall be subjected to the following test as described under 4.4: Examination of product 4.4.1 4.2.2 Sampling tests. The propellant shall be selected according to 4.2.2.1 and subjected to the following tests as described under 4.3: 3 Prov
21、ided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-7254G a. Nitrogen dioxide . 4.4.3 b. Hydrogen fluoride. 4.4.4 c. Specific gravity . 4.4.5 d. Total solids . 4.4.6 e. Iron content . 4.4.7 f. Water. 4.4.8 4.2.2.1 Sampling plan. 4.2.2.1.1 s. A lot sh
22、all consist of one of the following: a. The propellant produced in not more than 24 consecutive hours from a continuous process which is used to fill shipping containers directly from the process output. A continuous process shall be the production of product by continuous input of raw materials and
23、 output of finished product by one manufacturer in one plant with no change in manufacturing conditions or materials. b. The propellant from individual runs of a batch process which is used to fill shipping containers directly from the process output. A batch process shall be the production of produ
24、ct by runs from single additions of raw materials which are reacted and purified forming the product. c. The propellant from either or both the continuous and batch processes which is held in a single storage tank and subsequently withdrawn to fill shipping containers. The product shall be homogeneo
25、us at the time of withdrawal and shall not be added to while being withdrawn. addition to the storage tank, the contents shall constitute a separate lot. After each 4.2.2.1.2 Sample. A sample consists of not less than 150 milliters (mL) of propellant. Unless otherwise specified, quality conformance
26、tests shall be made on the sample of propellant taken directly from the shipping containers. When required, the sample shall be forwarded to a laboratory designated by the procuring activity for subjection to the quality conformance specified herein. TABLE II. Sampling for test Number of containers
27、in lot I I Number of containers to be sampled 2 - 25 26 - 150 151 - 1200 2 3 5 4.2.2.1.3 Containers of 400 liters or less water capacity. The number of containers selected for sampling from each lot shall be in accordance with Table II. The first and last Containers to be filled within a given lot s
28、hall be sampled. Other containers may be selected at random. If more than one lot is represented in the shipment, then each lot represented shall be treated as a separate shipment for sampling purposes. The contents of each selected container shall be thoroughly mixed by rolling and inverting immedi
29、ately prior 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-7254G to sampling. The samples may be obtained in any convenient manner. Each sample shall be subjected to all the tests of this specification. 4.2.2.1.4 Containers greater than 40
30、0 liters water capacity. Each container shall constitute a lot. Unless otherwise specified, the sample shall be from a point 6 to 12 inches from the bottom of the shipping container and shall be tested to determine compliance with this specification. 4.3 Rejection. When any sample tested in accordan
31、ce with 4.4 fails to conform to the requirements specified herein, the entire lot represented by the sample shall be rejected. Unless otherwise specified, disposition of rejected product shall be specified by the procuring activity (5.2). 4.4 Test methods. 4.4.1 Examination of product. The propellan
32、t shall be visually examined to determine compliance with the requirement specified herein. Examination to ensure that the propellant conforms to paragraph 3.3 shall be conducted after 25 mL of sample has been transferred to a 100-mL polychlorotrifluoroethylene vessel or equal. 4.4.2 Neutralization.
33、 The acid sample shall be neutralized by the following procedure. 4.4.2.1 Sample preparations. Trancsfer 1 mL of acid into a tared 2-mL polyethylene or polypropylene weighing vial and close the top. Weigh the vial with the sample and determine the sample weight. Sample sizes should average about 1.3
34、 g when using 0.5N alkali. 4.4.2.2 Procedure. The weighed ampoule shall be placed into a heavy- walled, glass stoppered 500-mL iodine flask, containing a measured amount of 0.5N sodium hydroxide which is in excess of that required for neutralization. The amount of alkali needed shall be calculated a
35、fter the sample weight is known. Cool the contents of the iodine flask in a salt-water-ice bath for five minutes. Displace the air in the flask with gaseous nitrogen conforming to MIL-PRF-27401. Immerse the plastic v.ial in a bath of powdered carbon dioxide or liquid nitrogen and freeze the liquid s
36、ample. Open the top of the vial, drop it into the flask after the air above the solution has been displaced, and quickly insert the glass stopper. The stopper shall be held in place with the thumb, and the flask shaken vigorously. The flask shall be allowed to stand for 15 minutes at room temperatur
37、e with occasional shaking during this time. A small quantity of distilled water shall be poured into the lip of the flask, the stopper loosened to allow the water to run into the flask and the stopper shall be rinsed with a stream of distilled water, also into the flask. Add 3 to 5 drops of phenolph
38、thalein indicator to ensure that the contents of the flask are slightly alkaline with respect to phenolphthalein. 4.4.2.3 Reagents and equipment. The following reagents and equipment shall apply as test conditions of 4.4.2. 4.4.2.3.1 Reagents. a. Sodium hydroxide solution, 0.5N: Dissolve 20 g of ACS
39、 reagent grade, low carbonate, NaOH in distilled water in a 1000-mL volumetric flask. Allow to cool and dilute to the mark with distilled water. Store in polyethylene and ensure the exclusion of atmospheric carbon dioxide. 5 Provided by IHSNot for ResaleNo reproduction or networking permitted withou
40、t license from IHS-,-,-MIL-PRF-7254G b. Distilled water. c. Phenolphthalein indicator. d. Gaseous nitrogen conforming to MIL-PRF-27401. 4.4.2.3.2 Equipment. a. Flask, iodine, heavy walled glass stoppered, 500 mL capacity. b. Ampoules, polyethylene or polypropylene, as required. c. Flasks, volumetric
41、, 1000 mL capacity. d. Ice bath, salt-water. e. Bath of powdered carbon dioxide or liquid nitrogen. 4.4.3 Nitrogen dioxide. The nitrogen dioxide content of all types of propellant shall be determined by the following procedure: 4.4.3.1 Procedure. The slightly alkaline sample of 4.4.2 shall be transf
42、erred quantitatively to a 250-mL volumetric flask and diluted to volume with distilled water. A 50-mL aliquot of this solution shall be withdrawn and transferred to a 250-mL flask and placed in the salt-water ice bath. The remaining solution shall be transferred to a plastic screw-cap container and
43、reserved for tests in 4.4.4. One mL of 1N H2S04 shall be added with stirring. Add without stirring an exact volume of 0.1N ceric solution sufficient to react the nitrite ion, amount can be calculated from the aliquot weight of the sample, plus 5 mL in excess. The beaker shall be placed on the stirri
44、ng platform and the electrode assembly immersed, and a blanket of gaseous nitrogen conforming to MIL-PRF-27401, Type I, shall cover the contents. Start the stirring motor and titrate the excess ceric solution with standardized 0.05N ferrous ammonium sulfate potentiometrically using the millivolt sca
45、le of a pH meter or a recorder. A plot of volume (mL) versus millivolts (mv) shall be drawn from which the end point can be determined. 4.4.3.2 Calculation. The NO2 content shall be calculated by the following formula: ( mL Ce4+ x N) - (mL Fe2+ x NI) x 4.601 0.2 w NO, ,percent by weight = where : N
46、= normality of the ceric solution NI = normality of the ferrous ammonium sulfate W = original weight in grams (4.4.2.1) 4.4.3.3 Reagents and equipment. The following reagents and equipment shall apply as test conditions of 4.4.3. 4.4.3.3.1 Reagents. 6 Provided by IHSNot for ResaleNo reproduction or
47、networking permitted without license from IHS-,-,- 9Qh 2047382 294 = . MIL-PRF-7254G a. Standard ceric solution 0.1N: Dissolve exactly 54.878 g of dry primary standard grade ceric ammonium hexanitrate (NH4) 2Ce (NO3) in 2N H2C04 and make up to the mark in a 1000-mL volumetric flask with 2N H2S04. Th
48、e ceric nitrate is dried for two hours at 60C (140F) in a vacuum oven. Store the solution in a polyethylene bottle with a gaseous nitrogen atmosphere. Solution which has been prepared in excess of seven days shall be standardized weekly before use with NIST primary standard grade arsenic trioxide us
49、ing ferroin as the indicator. b. Standard ferrous solution, 0.05N: Dissolve 19.608 g of ferrous ammonium sulfate hexahydrate, Fe(NH4)2(S04)2.6H20, with 0.5N sulfuric acid in a 1000-mL volumetric flask, and dilute to the mark with the same sulfuric acid solution. Standardize the ferrous sulfate reagent ,against 25 mL of the 0.1N ceric solution in triplicate, using the potentiometric procedure of 4.4.3.1. c. Sulfuric acid solution, 0.5NI lNI and 2
