1、 Beneficial comments (recommendations, additions, deletions) and any pertinent data that may be of use in improving this document should be addressed to: WR-ALC 642 CBSG/GBEA, 460 Richard Ray Blvd. Suite 200, Robins AFB, GA 31098. Since contact information can change, you may want to verify the curr
2、ency or this address information using the ASSIST Online database at http:/assist.daps.dla.mil. AMSC N/A FSC 3655 INCH-POUND MIL-PRF-27720G 1 September 2009 SUPERSEDING MIL-PRF-27720F 11 September 2000 PERFORMANCE SPECIFICATION TANK, STORAGE, LIQUID OXYGEN/LIQUID NITROGEN, TMU-24/E This specificatio
3、n is approved for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification covers two types of skid-mounted, 400-gallon tanks for air transport and storage of liquid oxygen and liquid nitrogen. 1.2 Classification. Tanks covered by this specification ar
4、e of the following types: Type I Liquid Oxygen 400 Gallon Type II Liquid Nitrogen 400 Gallon 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 cited in other sections of this spec
5、ification or recommended for additional 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 documents cited in sections 3 and 4 of this specification, whether or not they are
6、 listed. 2.2 Government documents. 2.2.1 Specifications and standards. The following specifications and standards 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. Provided by IHSNot
7、 for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-27720G 2 FEDERAL STANDARDS FED-STD-595 /24052 Green Semigloss FED-STD-595/36118 Gray, Flat or Lusterless COMMERCIAL ITEM DESCRIPTION A-A-50271 Plate, Identification A-A-58092 Tape, Antiseize, Polytetrafluorethyle
8、ne DEPARTMENT OF DEFENSE SPECIFICATION MIL-H-27301 Hose Assembly, Metal, Cryogenic Liquid Transfer MIL-DTL-83413 Connectors and Assemblies, Electrical, Aircraft Grounding, General Specification for DEPARTMENT OF DEFENSE STANDARDS AN929 Cap Assembly, Tube, Pressure Seal MIL-STD-810 Environmental Engi
9、neering Considerations and Laboratory Tests DEPARTMENT OF DEFENSE HANDBOOKS MIL-HDBK-838 Lubrication of Military Equipment MIL-HDBK-1791 Designing for Internal Aerial Delivery in Fixed Wing Aircraft MIL-HDBK-808 Finish, Protective, and Codes for Finishing Schemes for Ground and Ground Support Equipm
10、ent (Copies of these documents are available online at http:/assist.daps.dla.mil/quicksearch or from the Standardization Document Order Desk, Robbins Avenue, Building 4D, Philadelphia, PA 19111-5094.) 2.2.2 Other Government documents, drawings, and publications. The following other Government docume
11、nts and drawings form a part of this document to the extent specified herein. Unless otherwise specified, the applicable issues are those cited in the solicitation. USAF DRAWINGS 48B7796 Ring Assembly-Tiedown, 10,000 Pounds 68A39469 Plug 68A39470 Body 68A39471 Vacuum Pump Out and Relief Assembly 68A
12、39472 Cap Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-27720G 3 68A39473 Vacuum Pump Out Assembly Filter Assembly 7545352 Requirements for Finishes SA-ALC Ground Support Equipment ORDNANCE CORPS C8987830 Assembly, LOX Coupling, Male Half,
13、All Sizes C8987831 Assembly, LOX Coupling, Female B8987832 Gasket, LOX and LN2, All Sizes B8987833 Gasket, LOX or LN2-Dummy Drawing B8987839 Ring, Retaining A8987840 Ring, Retaining-Dummy Drawing C8987855 Seat, LOX Coupling, 1 inch C8987856 Cone, LOX Coupling C8987857 Nut, LOX Coupling C8987869 Cap,
14、 LOX, 1 inch C8987870 Plug, LOX C8987876 Seat, LN2 Coupling C8987877 Cone, LN2 Coupling C8987878 Nut, LN2 Coupling C8987888 Assembly, Liquid Nitrogen (LN2) Coupling, Male C8987889 Assembly, Liquid Nitrogen (LN2) Coupling, Female C8987890 Cap, LN2 C8987891 Plug, LN2 (Copies of documents and drawings
15、required by suppliers in connection with specific procurement functions should be obtained from the procuring activity or as directed by the contracting officer.) 2.3 Non-Government publications. The following documents form a part of this document to the extent specified herein. Unless otherwise sp
16、ecified, the issues of these documents are those cited in the solicitation or contract. AMERICAN NATIONAL STANDARDS INSTITUTE/AMERICAN SOCIETY FOR QUALITY (ANSI/ASQ) ANSI/ASQC Z1.4 Sampling Procedures and Tables for Inspection by Attributes (DoD-adopted) (ASNI documents may be obtained at www.ansi.o
17、rg or from American National Standards Institute 25 West 43nd Street, New York, NY 10036.) AMERICAN SOCIETY OF MECHANICAL ENGINEERS (ASME) ASME Boiler and Pressure Vessel Code Section VIII Unfired Pressure Vessels Provided by IHSNot for ResaleNo reproduction or networking permitted without license f
18、rom IHS-,-,-MIL-PRF-27720G 4 (ASME documents may be obtained at www.amse.org or from American Society of Mechanical Engineers, PO Box 2900, Fairfield, NJ 07007.) AMERICAN SOCIETY FOR TESTING AND MATERIALS (ASTM) ASTM E 1417 Liquid Penetrant Examination, Standard Practice For (DoD adopted) ASTM E1444
19、 Particle Examination, Magnetic (DoD adopted) (ASTM documents may be obtained at www.astm.org or from American Society for Testing and Materials, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959.) SOCIETY OF AUTOMOTIVE ENGINEERS (SAE) SAE ARP901 Bubble-Point Test Method SAE ARP1176 Oxygen Sys
20、tem and Component Cleaning and Packaging SAE AS4395 Tube Connection, Fitting End - Flared, Design Standard (DoD-adopted) SAE AS8090 Equipment, Towed Aerospace Ground, Mobility (DoD adopted) (SAE documents may be obtained at www.sae.org or from Society of Automotive Engineers, 400 Commonwealth Drive,
21、 Warrendale, PA 15096.) 2.4 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, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws a
22、nd regulations unless a specific exemption has been obtained. 3. REQUIREMENTS 3.1 First article. When specified (see 6.2), a sample shall be subjected to first article inspection in accordance with 4.2. 3.2 Recycled, recovered, or environmentally preferable materials. Recycled, recovered, or environ
23、mentally 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 cost. 3.3 Materials. All materials shall be suitably treated to resist corrosion due
24、 to electrolytic decomposition and any other atmospheric conditions that may be encountered during operational use or storage. The use of toxic chemicals, hazardous substances, or ODCs shall be avoided, whenever feasible (see 4.5.1). Provided by IHSNot for ResaleNo reproduction or networking permitt
25、ed without license from IHS-,-,-MIL-PRF-27720G 5 3.4 Interface. 3.4.1 Tank assembly base. The tank assembly, including all its accessories, shall be mounted on a structurally rigid skid-type base. This base shall serve as a skid base when the unit is placed on a flat, level, hard surface. The base s
26、hall also serve as a rigid platform to allow lifting, handling, and transporting of the complete unit. The overall size of the base shall be not less than the dimensions of the vertical projection of the tank assembly including the control housing. The bottom of the base shall be covered to provide
27、sufficient strength for movements of the full tank over loading ramps or rails with 0.5 inch wide rollers. The top of the base shall be covered to prevent entrance of dirt, debris, and precipitation. Drain openings shall be provided at the bottom (see 4.5.1, 4.5.6.3). 3.4.1.1 Skid base ends. Each en
28、d of the skid base shall be curved at the bottom with a 3-inch minimum radius over at least 90 , or turned up at a 30 to 45 angle so that the bottom rises to a height of not less than 1.25 inches above a flat surface on which the tank is placed (see 4.5.1, 4.5.6.3). 3.4.1.2 Forklift entries. The ski
29、d base shall have two lateral forklift entries, each 3.25 0.13 inches high by 10 0.13 inches wide, spaced 40 0.5 inches centerline distance. The forklift entries shall be placed approximately equidistant from the vertical center-of-gravity (CG) of the full tank. The entries shall extend the entire w
30、idth of the skid base, and shall not contain any obstructions that could impede movement of the forklift tines through the length of the entries. The entries shall restrain the forklift tines as necessary to prevent damage during lifting or movement of the tank assembly (see 4.5.1, 4.5.6.3). 3.4.2 L
31、iquid servicing hose. One 10-foot length of cryogenic liquid hose, conforming to MIL-H-27301, shall be provided with the tank assembly. The tank assembly shall provide protection and storage for the hose while connected to the servicing line. The storage provisions shall securely retain and protect
32、the hose when the tank is subjected to the accelerations specified herein. One end of the hose shall be connected to the 1-inch external pipe thread of the servicing line disconnect fitting (see 4.5.1). . The other end of the hose shall be as follows: a. For the Type I liquid oxygen tank, the other
33、end of the hose shall be provided with a 1-inch close nipple and a 1-inch female liquid oxygen coupling half assembly consisting of a coupling plug, nut, cone, and retaining ring conforming to Ordnance Corps drawings C8987870, C8987857, C8987856, and A8987840, respectively, assembled as shown on dra
34、wing C8987831 (see 4.5.1). b. For the Type II liquid nitrogen tank, the other end of the hose shall be provided with a 1-inch close nipple and a 1-inch female liquid nitrogen coupling half assembly consisting of a coupling plug, nut, cone, and retaining ring conforming to Ordnance Corps drawings C89
35、87891, C8987878, C8987877, and A8987840, respectively, assembled as shown on drawing C8987889(see 4.5.1) . 3.5 Design. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-27720G 6 3.5.1 Tank assembly. The tank assembly shall be a self-contained l
36、iquid oxygen or nitrogen transport and storage unit, consisting of a storage tank with inner and outer shells, a control housing assembly, necessary controls and accessories, and a skid base (see 4.5.1). The tank assembly shall be capable of: a. Being filled with liquid oxygen or nitrogen at a suppl
37、y location (see 4.5.1). b. Being transported (see MIL-HDBK-1791 for guidance) while filled with liquid oxygen or nitrogen and pressurized to 50 pounds per square inch gage (psig) (see 4.5.1). c. Storing the liquid with low evaporation loss rates during transport and at destination until needed, and
38、at that time transferring the liquid into smaller servicing containers (see 4.5.1). 3.5.2 Reliability. The tank assembly shall have a mean time between failures (MTBF) of not less than 21 servicing cycles at a 0.9 confidence level (see 4.5.1, 4.5.17, 4.5.19). 3.5.3 Maintainability. Parts and assembl
39、ies shall be located and mounted to provide adequate clearance for repair and other maintenance and, where practicable, to permit removal and replacement of any part or assembly by removing or disconnecting only mounting bolts or fasteners, panel doors, tubing, or control cables to the part or assem
40、bly being removed. All removable lines shall include special means for gripping the lines for attachment and detachment. The tank assembly, where practicable, shall include readily detachable and attachable type fittings in the liquid and vapor lines to permit rapid component removal and replacement
41、. Disconnect points shall be clearly indicated and identified. The design shall ensure clearance for operation, servicing and maintenance at low ambient temperatures by personnel wearing heavy gloves or mittens, bulky clothing and footgear. The design shall ensure maintenance and servicing can be pe
42、rformed using only common handtools. Intricate locking devices, controls, or fasteners that can be easily overtorqued by personnel lacking feel through thick gloves or numbness shall be avoided. Component installation design shall be such that the items can only be installed in their proper operatin
43、g position to avoid reverse installation (see 4.5.1, 4.5.20). 3.5.4 Pressure vessels. The liquid storage tank assembly, piping, and connections thereto shall meet the requirements of section VIII of the ASME Boiler and Pressure Vessel Code (see 4.5.1, 4.5.2). Also, the inner shell shall be certified
44、 under the code for the specified working pressure (see 6.2). 3.5.5 Inner shell. 3.5.5.1 Design pressure. The inner shell shall have a maximum working pressure the same as the inner shell pressure relief device (see 3.5.5.2). The normal working pressure shall be not less than 50 psig for transferrin
45、g liquid oxygen or nitrogen. The inner shell shall withstand an absolute pressure of 100 microns of mercury (Hg) or less with the annular space at atmospheric pressure. The shell shall not sustain damage when the annular space is evacuated to a high Provided by IHSNot for ResaleNo reproduction or ne
46、tworking permitted without license from IHS-,-,-MIL-PRF-27720G 7 vacuum or is pressurized to the outer shell pressure relief device maximum opening pressure (see 4.5.1, 4.5.2). 3.5.5.2 Inner shell safety head. A bursting-disc type safety head using a readily replaceable disc in a union-type fixture
47、shall be provided to relieve the inner shell vapor phase pressure to atmosphere should this pressure become excessive and the pressure relief valve fail to open. The safety head relief pressure shall be not greater than 1-1/2 times the inner shell maximum working pressure (see 4.5.1, 4.5.2.1). 3.5.5
48、.3 Inner shell vapor space pressure relief device. An automatic pressure relief device shall be connected into the vapor vent line between the outer shell and the vent line shutoff valve to relieve excess pressure. The relief device shall open at a pressure sufficiently below the inner shell burstin
49、g-disc type safety head breaking pressure to ensure against rupture of the safety head unless the relief device fails, but not less than 50 psig, and shall be sized to insure against the inner shell vapor space pressure exceeding 65 psig under the conditions specified (see 4.5.1, 4.5.16.4.1). 3.5.5.4 Sump and drain provisions. The inner shell shall have a sump wit
