1、AMSC N/A FSC 4720 MIL-PRF-83772C 30 September 2013 SUPERSEDING MIL-PRF-83772B (USAF) 8 JULY 1998 PERFORMANCE SPECIFICATION HOSE, ASSEMBLY, CRYOGENIC LIQUID, AIRCRAFT SERVICING This specification is approved for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. Thi
2、s specification covers a non-vacuum hose assembly for servicing aircraft with cryogenic liquids (liquid oxygen or liquid nitrogen). 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 docu
3、ments cited in other sections of this specification or recommended for additional information or as examples. While every effort has been made to ensure the completeness of these lists, document users are cautioned that they must meet all specified requirements of documents cited in sections 3, 4, o
4、r 5 of this specification, whether or not they are listed. 2.2 Non-government publications. The 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. ASME INTERNATION
5、AL ASME-B1.20.1 - Pipe Threads, (Inch) General Purpose (ASME documents may be obtained online at http:/www.asme.org/ or from ASME International, Three Park Avenue, New York, New York 10016-5990, USA.) Comments, suggestions, or questions on this document should be addressed to Oklahoma City Air Logis
6、tics Center/ENSDAA, 3001 Staff Drive, Suite 1AB81A, Tinker AFB, OK 73145 or emailed to af71tinker.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. INCH-POUND Provided by IHSNot for
7、 ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-83772C 2 AMERICAN SOCIETY FOR QUALITY (ASQ) ASQ-Z1.4 - Sampling Procedures and Tables for Inspection by Attributes (ASQ documents may be obtained online at http:/www.asq.org/ or from American Society for Quality, P.O
8、. Box 3005, Milwaukee, WI 53201-3005 or 600 North Plankinton Avenue, Milwaukee, WI 53203 USA.) 2.3 Order of precedence. Unless otherwise noted herein or in the contract, in the event of a conflict between the text of this document and the references cited herein (except for related specification she
9、ets), the text 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 Design and construction. The hose assembly shall be designed and constructed as specified herein for use
10、with cryogenic fluids such as liquid oxygen and liquid nitrogen (see 6.4). 3.1.1 Hose assembly. The hose assembly shall be capable of transferring oxygen or nitrogen through the hose and out the filler valve, as a liquid, at a minimum rate of 1 gallon per minute (gpm). The hose assembly shall confor
11、m to the weight, size, flexibility and other physical characteristics listed below: a. The length of the hose assembly shall be 10 feet 1 inch. b. The outer diameter of the outer covering shall be 1.25 inches maximum. There shall be no sharp or frayed edges. c. The weight of the hose assembly shall
12、not exceed 7.20 pounds. d. One end of the hose assembly shall terminate in a 0.75 inch National Pipe Thread (NPT) standard female fitting 14 threads per inch (tpi). The other end shall terminate in 1 inch NPT standard male fitting with 11.5 tpi. Guidance for pipe threads is provided in ASME B1.20.1.
13、 Both end fittings shall have hexagonal-type outer surface. e. The hose assembly shall be constructed such that the hose shall not suffer damage if handled or installed with bends whose radius is greater than or equal to seven inches. f. Provided that all other requirements of this specification are
14、 met, reclaimed materials may be used. 3.2 Performance. In addition to the design requirements, the hose assembly shall meet the performance requirements listed below. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-83772C 3 3.2.1 Proof press
15、ure. The hose assembly shall withstand a proof pressure of at least 150 psi without leakage for 1 minute. 3.2.2 Burst pressure. The hose assembly shall have a burst pressure of not less than 500 psi. 3.2.3 Operation. At an ambient temperature of 70 10F and a service pressure of 45 5 psi, the hose as
16、sembly shall be capable of being purged in 2 minutes or less and then shall be capable of servicing liquid nitrogen through the hose and out the filler valve, as a liquid, at a minimum rate of 1 gallon per minute (gpm). 3.2.4 Outer hose surface temperature. The outer surface temperature of the hose
17、assembly shall not drop below 15F after 10 minutes of servicing with liquid nitrogen at an ambient temperature of 70 10F. 3.2.5 Tensile strength. The hose assembly shall withstand a longitudinal tensile force of 300 pounds. 3.2.6 Abrasion. The hose assembly shall be capable of being dragged on a con
18、crete surface for 20,000 feet without structurally damaging the hose assembly. 3.2.7 Continuity. The hose assembly shall have electrical continuity from one end fitting, through the hose, to the other end fitting. 3.3 Recycled, recovered, or environmentally preferable materials. Recycled, recovered,
19、 or environmentally preferable materials should be used to the maximum extent possible, provided that the material meets or exceeds the operational and maintenance requirements, and promotes economically advantageous life cycle costs. 3.4 Identification of product. The hose assembly shall be marked
20、for identification as prescribed by the authority. The marking shall be clearly readable (see 6.2). In addition to markings required by the procuring activity, hose containers and shipping containers shall be marked as follows: HOSE ASSEMBLY, CRYOGENIC LIQUID, AIRCRAFT SERVICING 3.4.1 Precautionary
21、markings. The following marking also shall be included on the hose containers and shipping containers: DO NOT ALLOW OIL OF ANY KIND TO BE USED ON OR COME IN CONTACT WITH THIS HOSE 3.5 Cleaning. All parts of the hose assembly which come in contact with liquid oxygen shall be cleaned in accordance wit
22、h accepted industrial practices for breathing class oxygen using an oxygen-safe cleaning solvent. The same batch of cleaning solvent shall be used to clean quantities not greater than 50 hoses. Immediately following cleaning, hoses shall be dried with Provided by IHSNot for ResaleNo reproduction or
23、networking permitted without license from IHS-,-,-MIL-PRF-83772C 4 oil-free air or gaseous nitrogen (see 6.4) and shall then have their ends sealed. The interior of the inner hose and end fittings of the cleaned hose assemblies shall meet the requirements listed below: a. Particle (metal or non-meta
24、l;) count and sizes (1) No particle greater than 2500 microns. (2) No more than 1 particle between 700 and 2500 microns. (3) No more than five particles between 175 and 700 microns. b. Non-volatile residue shall not exceed 0.001 grams per square foot of the inner hose interior surface area. 4. VERIF
25、ICATION 4.1 Classification of inspections. The inspection requirements specified herein are classified as follows: a. Qualification inspection (see 4.4). b. Conformance inspection (see 4.5). 4.1.1 Requirements cross-reference matrix. Table I provides a cross-reference matrix of the section 3 require
26、ments tested or verified in the paragraphs below. 4.2 Test conditions. Unless otherwise specified, all tests shall be performed at an ambient temperature of 70 10F. 4.3 Test report. The results of this testing shall be documented as prescribed by the procuring activity (see 6.2). TABLE I. Requiremen
27、ts cross-reference matrix. Requirement Verification Requirement Verification 3.1.1 4.4.3, 4.4.4 3.2.6 4.4.6 3.2.1 4.4.4 3.2.7 4.4.8 3.2.2 4.4.9 3.4 4.4.3 3.2.3 4.4.7 3.4.1 4.4.3 3.2.4 4.4.5.1 3.5 4.4.2 3.2.5 4.4.5.2 4.4 Qualification inspections. These qualification tests shall be performed on 1 hos
28、e assembly. The tests shall be performed in the order presented below. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-83772C 5 4.4.1 Test article. The test hose assembly shall be randomly selected by an authorized government representative f
29、rom hose assemblies which have been manufactured in the same manner that all hose assemblies to be bought per the contract will be manufactured. If the test is successful, the remaining hose assemblies shall be included in the first lot of hose assemblies to be delivered to the Government. 4.4.2 Cle
30、aning test. The cleaning test shall consist of particulate test and a non-volatile residue (NVR) test. 4.4.2.1 Particulate test. A 15-ounce sample of an acceptable oxygen-safe commercial cleaning solvent shall be poured through the selected test sample hose assembly held vertically, such that the in
31、terior walls are rinsed and flushed with solvent. The liquid leaving the bottom of the hose shall be collected in a clean container and filtered by means of a vacuum pump through a 10 micron-pore membrane filter. The filtered solvent, in its cleaned container, shall be saved for later use in the non
32、-volatile residue test. The particulate (metal or nonmetal) found on the membrane filter surface shall have (1) no particle greater than 2500 microns, (2) no more than 1 particle between 700 and 2500 microns and, (3) no more than 5 particulates between 175 and 700 microns. Immediately after the rins
33、ing of this test sample hose assembly, it shall be thoroughly dried and its ends shall be resealed. 4.4.2.2 Non-volatile residue test. To determine the amount of NVR, the solvent used in the particulate test (4.4.2.1) shall be dried using an evaporate process and the residue weighed (see 6.9). The w
34、eight of the NVR shall be divided by the interior surface area of the hose assembly and the value obtained shall be less than 0.001 grams per square foot. 4.4.3 Examination of hose. The hose assembly shall be physically inspected to ensure the following: a. The total length is 10 feet 1 inch. b. The
35、 outer diameter of the outer covering is not more than 1.25 inches. c. The total weight does not exceed 7.20 pounds. d. The hose assembly terminates in a 0.75 inch NPT standard female fitting having 14 tpi at one end, and a 1 inch NPT standard male fitting with 11.5 tpi at the other end. Both end fi
36、ttings shall have a hexagonal-type outer surface. e. The outer covering is free from sharp or frayed edges. f. The markings are as prescribed by the procuring authority and all hoses carry the precautionary labeling (see 6.2). 4.4.4 Bend radius test. The hose assembly shall be installed in a fixture
37、 as shown in figure 1, and shall be rotated at a rate of at least 10 rpm for 45 minutes fifteen (15) minutes at each of three different heights (H) of 1, 3 and 6 feet, with a liquid nitrogen flow rate of at least 1 Provided by IHSNot for ResaleNo reproduction or networking permitted without license
38、from IHS-,-,-MIL-PRF-83772C 6 gpm. The hose shall neither rupture nor leak as a result of this test, nor shall it develop sharp or frayed edges that would be dangerous in operational use. The integrity of the hose shall be verified after the test by pneumatically pressurizing the hose to 150 5 psig
39、and then submerging the hose in water. There shall be no steady stream of air bubbles evidencing leakage from the hose assembly. 4.4.4.1 Alternate bend radius test. When specified by the procuring authority as an alternate to paragraph 4.4.4, the hose assembly shall be attached to a solid support, s
40、tretched out straight, and the hose shall have liquid nitrogen pumped through it at a rate of at least 1 gpm for 15 minutes. After the 15 minutes, the flow of liquid nitrogen shall be turned off. a. Within two minutes, the hose shall be completely coiled around a 10 inch square mandrel and then it s
41、hall be uncoiled and straightened out. b. Liquid nitrogen shall be pumped through the hose at a rate of 1 gpm, or more, for at least 1 minute. After this minute, turn off the liquid nitrogen source. Repeat steps a and b above a total of 100 times; 50 times coiling clockwise; then 50 times coiling co
42、unterclockwise. Following the completion of the 100 coils, hose assembly integrity shall be verified by pneumatically pressurizing the hose to 150 5 psig, and then submerging the hose in water. There shall be no steady stream of air bubbles evidencing leakage from the hose assembly. Provided by IHSN
43、ot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-83772C 7 FIGURE 1. Bend radius test. 4.4.5 Tensile and temperature tests. The temperature test shall be run during the first 10 minutes of the 30 minute tensile test. 4.4.5.1 Outer hose surface temperature test
44、. The male end of the hose assembly shall be attached to a solid support and liquid nitrogen flowed through it and out of the other end at a flow rate of at least 1 gpm. Three thermocouples shall be placed on the outer covering of the hose assembly in order to record the surface temperature througho
45、ut the first 10 minutes of liquid nitrogen flow. Two of the thermocouples shall be attached approximately 1 foot from either end of the hose assembly, and the third shall be attached near the middle. No external heat source shall be directed toward the hose or thermocouples during this test. The hos
46、e assembly temperatures shall not fall below 15F after liquid nitrogen has flowed through the hose for 10 minutes. 4.4.5.2 Tensile strength test. Without a break in the flow of liquid nitrogen per paragraph 4.4.5.1, a flow of 1 gpm shall continue for additional 20 minutes. Immediately following thes
47、e 20 minutes, and just after the flow is stopped, a tensile force of 300 pounds shall be applied at the free end of the hose. This pulling and stretching force shall remain for 1 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-83772C 8 minute
48、. The hose shall then be proof pressure tested per paragraph 4.4.4. The hose assembly shall maintain the 150 5 psig pressure for at least 1 minute. 4.4.6 Abrasion drag test. The hose assembly shall be placed on a dry, brushed concrete surface, such as a runway, and dragged a distance of at least 20,
49、000 feet at a speed of 4 to 5 MPH. The end of the hose with the male end fitting shall be approximately 18 inches above the ground, held stationary, and shall be horizontally oriented with the centerline of the hose pointing in the direction being dragged. The hose shall be visually inspected each 5,000 feet and at the end distance of 20,000 feet. The extent of wear shall b
