1、MIL-PRF-27401G 07 August 2013 SUPERSEDING MIL-PRF-27401F 10 January 2008 PERFORMANCE SPECIFICATION PROPELLANT PRESSURIZING AGENT, NITROGEN AMSC N/A FSC 9135 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. METRIC Comments, suggestions, or questions on this document s
2、hould be addressed to AFPA/PTPT, 2430 C Street, Bldg 70, Area B, Wright-Patterson AFB OH 45433-7632 or e-mailed to AFPA.PTPSwpafb.af.mil. Since contact information can change, you may want to verify the currency of this address information using the ASSIST Online database at https:/assist.dla.mil. P
3、rovided by IHSNot for Resale-,-,-MIL-PRF-27401G 2 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 three grades and two types of nitrogen. 1.2 Classification. The nitrogen will be o
4、f the following types and grades as specified (see 6.2). 1.2.1 Types. The types of nitrogen are as follows: Type I - Gaseous Type II - Liquid 1.2.2 Grades. The grades of nitrogen are as follows: Grade A - 99.5 percent pure, aerospace practices Grade B - 99.99 percent pure, space vehicle and cabin en
5、vironment Grade C - 99.995 percent pure, special applications 1.3 Part or identifying number (PIN). The PINs to be used for nitrogen acquired to this specification are created as follows: M 27401 - X X Example of PIN: M27401-2B Grade (see 1.2.2). Type (see 1.2.1). Use 1 for Type I, 2 for Type II. Sp
6、ecification number. Prefix for military specification. 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed in this section are specified in sections 3, 4, or 5 of this specification. This section does not include documents cited in other sections of this specification or recommended for additi
7、onal information or as examples. While every effort has been made to ensure the completeness of this list, document users are cautioned that they must meet all specified requirements of documents cited in sections 3, 4, or 5 of this specification, whether or not they are listed. 2.2 Government docum
8、ents. 2.2.1 Specifications, standards, and handbooks. The following specification forms a part of this document to the extent specified herein. Unless otherwise specified, the issue of this document is the Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHSM
9、IL-PRF-27401G 3 one cited in the solicitation or contract (see 6.2). DEPARTMENT OF DEFENSE STANDARDS MIL-STD-101 Color Code for Pipelines and for Compressed Gas Cylinders MIL-STD-1411 Inspection and Maintenance of Compressed Gas Cylinders COMMERCIAL ITEM DESCRIPTIONS A-A-58092 Tape, Antiseize, Polyt
10、etrafluorethylene A-A-59860 Valves, Cylinder, Gas (For Compressed or Liquefied Gases) (Copies of these documents are available online at https:/assist.dla.mil or from the Standardization Document Order Desk, 700 Robbins Avenue, Bldg 4D, Philadelphia PA 19111-5094.) 2.3 Non-government publications. T
11、he following documents form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract. ASTM INTERNATIONAL ASTM E 29 Standard Practice for Using Significant Digits in Test Data to Determine Conform
12、ance with Specifications (DoD Adopted) ASTM F 307 Standard Practice for Sampling Pressurized Gas for Gas Analysis (DoD Adopted) ASTM F 310 Standard Practice for Sampling Cryogenic Aerospace Fluids (DoD Adopted) (Copies of these documents are available online at http:/www.astm.org or by mail at ASTM
13、International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken PA 19428-2959) COMPRESSED GAS ASSOCIATION (CGA) CGA G-10.1 Commodity Specification for Nitrogen CGA P-15 Filling of Industrial and Medical Nonflammable Compressed Gas Cylinders (Copies of these documents are available online at h
14、ttp:/ or by mail from the Compressed Gas Association, Inc., 14501 George Carter Way, Suite 103, Chantilly, VA 20151) 2.4 Order of precedence. In the event of a conflict between the text of this document and the references cited herein, the text of this document takes precedence. Nothing in this docu
15、ment, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 3. REQUIREMENTS 3.1 Grade requirements. The nitrogen purity and the impurity concentrations as applicable to each grade of nitrogen shall conform to the limits of Table I when tested in accordanc
16、e with the applicable test method also specified in Table I. Other limits and tests may be specified by the procuring activity (see 6.2). 3.2 Limiting values. The following applies to all specified limits in this specification: For purposes of determining conformance with these requirements, an obse
17、rved value or a calculated value Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHSMIL-PRF-27401G 4 shall be rounded off in the last right-hand digit used in expressing the specification limit, using the Rounding Method of ASTM E29. 3.3 Filter. 3.3.1 Contai
18、ners. A filter with a rating of at least 10-micrometer nominal and 40-micrometer absolute rating shall be installed between the manufacturers plant system and the manifold used to fill the gas or liquid containers for delivery. 3.3.2 Pipelines. A filter with a rating of at least 3.5-micrometer nomin
19、al and 12-micrometer absolute rating shall be installed downstream of compressors and/or converters and as close to the users interface as possible for delivery into pipelines. The filter shall remove all particles greater than 100 micrometers in any dimension. TABLE I. Grade limits for nitrogen. Gr
20、ade Test Method A B C Purity a, b, % by vol, min 99.5 99.99 99.995 4.4.1 Impurities, ppm by volume, max Water Total hydrocarbons as methane Oxygen Hydrogen Argon eCarbon dioxide eCarbon monoxide e5000 c26.3 58.3 5000 - d- d- d- d100 c11.5 5.0 50 - d20 5 5 50 c5.7 5.0 20 0.5 2 5 5 - 4.4.2 4.4.2 4.4.2
21、 4.4.2 4.4.2 4.4.2 4.4.2 Particulate f, mg/L, max 1.0 1.0 1.0 4.4.3 Notes. a. Percent nitrogen includes trace quantities of argon (Grade A), neon, and helium. b. If direct method is required, use the alternate method found in 6.3. c. Sum, in parts per million (ppm), of water, hydrocarbons, oxygen, a
22、nd if applicable, argon, hydrogen, carbon monoxide, and carbon dioxide. d. No limit for this grade. e. If required by contract (see 6.2). f. Applies only to Type II (Liquid) nitrogen. The particulate limit may be removed by the procuring activity (see 6.2). Provided by IHSNot for Resale-,-,-MIL-PRF-
23、27401G 5 3.4 Filled containers (Type I only). 3.4.1 Pressure. The container filling pressure (see 6.2) shall not differ from that required by the contract by more than 1.0% at 21C (70F) when tested as specified in 4.5.1. In no case shall the filling pressure exceed the rated service pressure of the
24、container. 3.4.2 Leakage. Containers shall not leak when tested according to 4.5.2. 3.4.3 Inspection and maintenance. Compressed gas cylinders shall be inspected, maintained, and charged according to 4.5.3. 4. VERIFICATION 4.1 Points of inspection (see 6.2). 4.1.1 Containers. Unless otherwise specif
25、ied, acceptance tests shall be conducted at the site of filling prior to shipment or departure. 4.1.2 Pipeline. When Type I nitrogen is delivered in pipeline, acceptance tests shall be conducted immediately prior to entering the users system. 4.2 Conformance inspection. Quality conformance tests sha
26、ll consist of the following: a. Individual tests (Type I only) 4.2.1 b. Sampling tests 4.2.2 4.2.1 Individual tests (Type I only). Each container shall be subjected to the following tests as described under 4.5: a. Filling pressure 4.5.1 b. Leakage 4.5.2 4.2.2 Sampling test. The number of nitrogen c
27、ontainers shall be selected in accordance with Table II and subjected to the tests required by Table I. TABLE II. Sampling for test. Number of containers in lot Number of containers to be sampled 1 1 2 40 2 41 70 3 71 over 4 Provided by IHSNot for Resale-,-,-MIL-PRF-27401G 6 4.2.3 Lot definitions. 4
28、.2.3.1 Type I. A lot is defined as all of the nitrogen supplied in one or more container(s) filled from a single manifold at the same time. 4.2.3.2 Type II. Each filled container shall constitute a lot. 4.2.3.3 Container Assemblies. A shipping conveyance consisting of multiple cylinders or tubes tha
29、t are interconnected by a single manifold that equalizes the pressure across all cylinders/tubes to form a single unit is considered a single container for the purpose of this specification. 4.2.4 Sample. Each sample shall be of sufficient size to conduct all the quality conformance tests as specifi
30、ed herein. Unless otherwise specified, the quality conformance tests shall be performed on each required sample (see 6.2). When required, an equivalent sample shall be forwarded to a laboratory designated by the procuring activity for testing. 4.2.4.1 Sampling methods. Each sample taken for analysis
31、 shall be representative of the entire contents of the container being sampled. All equipment used shall be made of suitable materials. Unless otherwise specified in the acquisition requirements (see 6.2), sampling shall be accomplished by one of the following methods. a. Type I, gaseous nitrogen ma
32、y be sampled in accordance with ASTM F 307 and Type II, liquid nitrogen may be sampled in accordance with ASTM F 310. It is critical that the outlet of the sampling port be clean and free of contaminants. b. Connect the shipping container being sampled directly to the analytical equipment using suit
33、able pressure regulation as required to prevent over-pressurization of the equipment. 4.2.5 Non-Bulk Containers. Non-bulk containers are defined as containers of 400 liters or less water capacity. The number of containers filled with Type I (gaseous) nitrogen selected for sampling from each lot shal
34、l be in accordance with Table II. The first and last containers to be filled within a given lot are typically sampled. Other samples may be selected at random. Every container filled with Type II (liquid) nitrogen shall constitute a lot and will be sampled. 4.2.6 Bulk transports. Bulk containers are
35、 defined as containers of more than 400 liters water capacity. Each bulk container filled with Type I (gaseous) or Type II (liquid) nitrogen constitute a lot and shall be sampled. 4.2.6.1 Continuous service. Unless otherwise specified by the procuring activity, the following sample option for nitrog
36、en shall be used for storage and transport tanks engaged in continuous nitrogen service (see 6.2). Contractor shall sample the contents of each transport tank engaged in continuous nitrogen service at least once every seven days at uniform intervals of time. Samples shall be taken from the filled tr
37、ansport tanks. Contractor shall sample the contents of each transport tank when entering continuous service and when the transport tank has remained empty for a period greater than 24 hours. When empty, all ports and vents shall remain closed to the atmosphere. While in continuous service, complianc
38、e with quality conformance tests specified herein shall be determined by sampling the filling point storage tank after each addition or, in case of continuous production, at established intervals not less frequent than once every 24 hours. When a storage tank is being filled during a change of duty
39、shift, sampling shall be performed after filling. (see 6.5.1) 4.2.7 Pipelines. Unless otherwise specified in the contract, the following sampling plan shall be used for pipelines: Sampling to determine specification compliance shall be accomplished by drawing liquid phase samples from each filled co
40、ntainer transporting liquid for conversion to gas and by drawing samples from the gas supplied into the users system (see 6.2). Provided by IHSNot for Resale-,-,-MIL-PRF-27401G 7 4.2.7.1 Liquid phase samples. Liquid phase samples shall be tested for each parameter in applicable grade of Type II nitr
41、ogen. Sampling under the “continuous service“ provisions can be applied. 4.2.7.2 Gas phase samples. a. Samples shall be tested for each parameter in the applicable grade of Type I nitrogen. Samples shall be drawn in accordance with 4.2.4 from a point immediately prior to entering the users system. T
42、he frequency of sampling shall not be less than once every seven days at regular intervals. b. When specified in contract, in-line samples shall be drawn and tested with continuous monitors for each parameter specified in contract for the applicable grade of Type I nitrogen. Each analyzer shall be e
43、quipped with a permanent recording device. When specified in contract, an alarm system to indicate contaminant contents in excess of specified maximum shall be provided (see 6.2). c. After internal exposure of the pipeline to the atmosphere or other foreign materials, a sample of gas shall be taken
44、from the pipeline prior to delivery into the users system at a point between the final filter and the interface with the Government system. The sample shall be tested for each parameter in applicable grade of Type I nitrogen. After cleaning operation, the sample shall also be tested for contaminatio
45、n by vapors from the cleaning materials. 4.3 Rejection. When any sample tested in accordance with 4.4 fails to conform to the requirements specified herein, the entire lot represented by the sample shall be rejected. 4.4 Analytical procedures. Unless otherwise specified, samples shall be analyzed ac
46、cording to the procedures described in 4.4.2 (see 6.2). Calibration gas standards may be required to calibrate (zero and span) analytical instruments used to determine the purity and impurity contents of the nitrogen. The accuracy of the calibration gas standards is to be traceable to the National I
47、nstitute of Standards and Technology. 4.4.1 Nitrogen content. The nitrogen content in percent shall be found by determining the aggregate impurities by the methods described in 4.4.2. The nitrogen purity is the value obtained when the aggregate impurities, expressed as volume percent, is subtracted
48、from 100 percent. 4.4.2 Impurities. Methods shall be selected from those of CGA G-10.1. 4.4.3 Particulate content. A filter holder assembly, (Pall Life Sciences part number 2220), or equivalent modified as shown on Figure 1 shall be attached to the withdrawal line of the vessel to be utilized to fil
49、l the tanks. A preweighed filter paper (47 mm glass fiber paper, type A/E or equivalent) shall be placed on top of another filter of the same kind. The filters shall then be placed on the porous filter support, which, in turn, shall be placed in the filter holder as shown on Figure 1. The male threads of the filter holder shall be wrapped with thin, nonadhesive-backed polytetrafluorethylen
