1、MIL-P- 27456C (USAF) 26 September. i967 SUPERSEDING MIL-P-27456B(USAF) 3 May 1962 MILITARY SPECIFICATION PURGING UNIT, AIR, LIQUID OXYGEN STORAGE .TANKS GSU-62/M 1. SCOPE 1.1 This specification covers a liquid-oxygen storage tank air purging unit, designated GSU- 62/M. 2. APPLICABLE DOCUMENTS 2.1 Th
2、e following documents of the issue in effect on date of invitation for bids or request for proposal, form a part of the specification to the extent specified herein. SPEC IF IC AT IONS Federal CC-M-641 NN-P-530 TT-E-489 TT- P-664 TT-W-572 Mi lit ary MIL-C-104 MIL-P-116 MIL-D- 1000 MIL-T-5542 MIL-C-5
3、756 MIL-1-6866 MIL-1-6868 Motor, Alternating Current (Integral Horsepower, 200 HP And Smaller) Plywood, Flat Panel Enamel, Alkyd Gloss, (For Exterior And Interior Surfaces) Primer, Coating, Synthetic, Rust- Inhibiting, Lacquer-Resisting Wood-Preservative; Water-Repellent Crates, Wood; Lumber And Ply
4、wood Sheathed, Nailed And Bolted Preservation, Methods Of Drawings, Engineering And Associated Lists Thread Compound, Antiseize And Sealing, Oxygen Systems Cable And Wire, Power, Electric, Portable Inspection, Penetrant Method Of Inspection Process, Magnetic Particle FSC 3655 Provided by IHSNot for
5、ResaleNo reproduction or networking permitted without license from IHS-,-,-mL-P-27456C(USAF) MIL-M-8090 MIL-A-8421 MIL- S-85 12 MIL-C-8638 MIL-E- 16298 STANDARDS Mi li tary MIL-STD-129 MIL-STD-130 MIL- STD- 143 MIL-STD-281 MIL-STD-470 MIL-STD-808 MIL-STD-8 10 MIL- STD-8 26 MIL-STD-831 MIL-STD-1186 D
6、RAWINGS Ordnance Corps C8987830 Air Force 48B7796 55C6 18 2 Mobility Requirements, Ground Support Equipment, General Specification For Air Transportability Requirements, General Specification For Support Equipment, Aeronautical, Special, General Specification For The Design Of Cleaning Compound; Oxy
7、gen Systems Electric Machines Having Rotating Parts And Associated Repair Parts; Packaging Of Marking For Shipment And Storage Identification Marking Of US Military Property Specifications And Standards, Order Of Precedence For The Selection Of Automobile, Trucks, Truck-Tractors, Trailers And Traile
8、r Dollies; Preserva- tion And Packaging Of Maintainability Program Requirements, (For Systems And Equipment) Finishes, Protective And Codes For Finishing Schemes For Ground And Ground Support Equipment Environmental Test Methods For Aerospace And Ground Equipment Electromagnetic Interference Test Re
9、quirements And Test Methods Test Reports, Preparation Of Cushioning, Anchoring, Bracing, Blocking And Waterproofing; With Appropriate Te s t Met hods Assembly, LOX Coupling, Male Half, All Sizes Ring Assembly - Tie Down 10,000 Lb. Connectors - 440 Volt/416 7olt Power Cable 2 Provided by IHSNot for R
10、esaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P- 27456C (USAF) PUBLICATION Air Force-Navy Aeronautical Bulletin 166 Colors, List Of Standard Aircraft Glossy (Copies of specifications, standards, drawings, and publications required by suppliers in connection with speci
11、fic procurement functions should be obtained from the procuring activity or as directed by the contracting officer.) 2.2 Other publications. The following documents form a part of this speci- fication to the extent specified herein. Unless otherwise indicated, the issue in effect on date of invitati
12、on for bids or request for proposal shall apply National Fire Protection Association Pamphlet 70 National Electrical Code (Copies of the NFPA pamphlet may be obtained upon application to the National Fire Protection Association, 60 Batterymarch Street, Boston 10, Massachusetts.) American Society PTC
13、-19.5:4 (Copies of ASME power American Society of M New York.) 3. REQUIREMENTS of Mechanical Engineers Supplement On Instruments And Apparatus: Part 5, Chapter 4, Flow Measurement By Means Of Standardized Nozzles And Orif ice Plates test code may be obtained upon application to the chanical Engineer
14、s, 29 West 39th Street, New York 18, . 3.1 Preproduction. This specification makes provision for preproduction testing. 3.2 Components. The purging unit shall consist of the following major components: Item Name See Requirement a. Blower 3.8.1 b. Power unit 3.8.2 c. Heater . 3.8.3 d. Servicing hose
15、3.8.4 e. Instrument and control panel 3.8.5 f. Controls, instruments, and accessories 3.8.6 g. Cabinet 3.8.7 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-27456C 36 777770b 0247Li70 5 W 3.3 General specification. The requirements of MIL-S-8
16、512 apply as require- ments of this specification with the exceptions and additions specified herein. When the two specifications conflict, this specification shall govern. 3.4 Selection of specifications and standards. Specifications and standards for necessary commodities and services not specifie
17、d herein shall be selected in accordance with MIL-STD-143. 3.5 Materials. 3.5.1 Fungus-proof materials. Materials that are nutrients for fungi shall not be used where practicalto avoid them. sealed, they shall be compounded or treated as necessary to insure against fungus attack. Fungicidal treatmen
18、t will not be necessary for materials used in a hermetically sealed enclosure. Where used and not hermetically 3.5.2 Gasket and insulating materials. Plastic, rubber-like, rubber, or similar gasket and insulating materials shall be compounded to insure their suitability for the intended application
19、and, where applicable, their resistance to hydrocarbons or iow temperatures. 3.5.3 Packings, gaskets, seals, and other nonmetallic components shall be suitable for use under the conditions specified in 3.7. 3.5.4 Metals. Wherever practicable, lightweight metals shall be used in the construction of t
20、he purging unit. 3.5.5 Combustible materials. Readily combustible materials shall not be used in the purging unit. 3.5.6 Metallic surfaces. Metallic surfaces of the purging unit that contact the purging air shall be fabricated from aluminum, brass, copper, or stainless steel. 3.5.7 Lubricants. The p
21、urging unit shall be designed to fully comply with the requirements specified herein, using only Government specification lubricants. 3.6 Design and construction. constructed that no parts will work loose in service. It shall be built to withstand the strains, jars, vibrations, and other conditions
22、incident to shipping, storage, installation, and service. The purging unit shall be so designed and 3.6.1 Reliability. The purging unit shall have a mean-time-between-failures (MTBF) of not less than 435 hours with a minimum reliability of 94 percent for a 24-hour mission at a confidence factor of 0
23、.90. (See 6.3.3 and 6.3.4) 3.6.2 Endurance. The purging unit shall be designed and constructed to provide satisfactory operation for 1,000 hours at rated capacity and pressure between overhauls. (See 4.6.7) 3.6.3 Maintainability. The purging unit design and construction shall provide for compliance
24、with the maintainability requirements specified in MIL-STD-470. 4 - - - -_ Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I - MIL-P-2745bC 36 W 7777706 0247473 7 MIL-P-27456C (USAF) 3.6.3.1 incorporate features insuring ope-rating clearance for faci
25、litating maintenance and servicing at low ambient temperatures by personnel wearing heavy gloves or mittens and handicapped by bulky clothing and footgear. To the maximum-practicable extent, maintainability provisions shall 3.6.3.2 Intricate locking devices, controls, and threaded fastenings that ca
26、n be easily overtorqued by personnel lacking feel through thick gloves or numbness shall be avoided where possible. 3.6.4 Operating supplies. The purging unit shall be designed to perform as specified herein when operated with electric power having the character- istics specified in 3.8.2.1.1. It sh
27、all require no operating supplies other than electric power and replacement parts. 3.6.5 Mobility. requirements of MIL-M-8090 and those specified for type II, group C mobility. 3.6.6 Controls. The purging unit shall be equipped with all controls necessary to permit ready starting, stopping, and spee
28、d regulation. The purging unit shall be designed to meet the general 3.6.7 Protective covers. Cover plates, gaskets, and fittings necessary for the protection of contained apparatus during operation, storage, or shipment shall be provided. 3.6.8 Operation and maintenance tools. No special tools, oth
29、er than common handtools and those tools normally available in motor shops, shall be required for proper operation, maintenance, and repair of the purging unit. 3.6.9 Hoisting and tiedown provision. Tiedowns in accordance with MIL-A-8421 shall be pr.ovided and, where practicable, shall serve as both
30、 tiedown and hoisting provisions. The hoisting provisions shall be capable of withstanding a vertical acceleration of 3g. The hoisting and tiedown provisions shall include four or more tiedown ring assemblies conforming to Drawing 49B7796. I 3.6.10 Acceleration forces. The purging unit shall be cons
31、tructed to withstand the acceleration forces specified in MIL-A-8421 for flight and taxiing and emergency landing loads. 3.6.11 Lubrication. Wherever practicable, permanently lubricated components, or components not requiring lubrication, shall be used in the design of the purging unit. Grease and o
32、il seals shall be designed and located to provide maximum accessibility for inspection and replacement, 3.6.12 Parts subject to wear. The purging unit shall be designed to provide for lubrication of all parts subject to wear. Wherever practicable, such parts shall be designed and constructed to be r
33、eadily renewable. All grease fittings and other lubrication points shall be located to be readily accessible. (See 3.14.5) 3.6.13 Common parts. The purging unit shall be designed to provide for the maximum practicable interchangeability of hardware and fastening devices by 5 -_ .- . . Provided by IH
34、SNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-P-2745bC 36 W 7779706 0247472 7 MIL-P-27456C(USAF) using the minimum number of types and sizes of bolts, screws, nuts, washers, and other comon hardware. 3.6.14 Covers or plates. Covers or plates that must be rem
35、oved for component.adjustments or for component or part removal shall be equipped with substantial quick-disconnect fittings. 3.6.15 Tubing, lines, and electrical wiring. All tubing, lines, and electrical wiring shall be located in protected positions, securely fastened to framework or body structur
36、es, and provided with protective sleeves, grommets, or similar devices at each point where they pass through members, except where a through-the-frame-type connector is provided. 3.6.16 Piping. shall be at least 1 inch inside diameter and shall terminate at the exterior of the unit in a 1 inch stand
37、ard external pipe thread. The piping between the blower and the servicing hose 3.6.16.1 Pipe thread compound. Pipe thread compound, conforming to MIL-T-5542; thin, nonadhesive-backed, polytetrafluoroethylene tape; or other pipe thread sealing material, specifically approved by the procuring activity
38、, shall be applied to threads prior to assembly of all pipe-threaded fittings. 3.6.17 Air flow. as shown on Figure 1. The flow of air during the purging operation shall be 3.7 Perf ormance. 3.7.1 Flow rate. At an ambient temperature of -65“ Fahrenheit (F) and standard atmospheric pressure, the purgi
39、ng unit shall be capable of con- tinuously delivering air at a minimum rate of 6 pounds per minute (pm) with a discharge pressure of not less than 5 pounds per square inch gage (psig) measured at the discharge end of the servicing hose specified under 3.8.4. The unit shall be capable of operating ag
40、ainst a discharge pressure of O to 5 psig, measured at the discharge end of the servicing hose, throughout the ambient temperature range of -65“ to +130F. 3.7.2 Outlet temperature. an outlet temperature at the discharge end, of 350“ f10“F when operating in ambient temperatures ranging from -65“ to c
41、130“F with the flow rate specified in 3.7.1. In addition, the unit shall be capable of achieving an outlet temperature of 350“ ?1O0F within 10 minutes after activation at an ambient temperature of -65F. (See 4.3.3.3 and 4.6.6) The purging unit shall be capable of maintaining 3.7.3 Operating time. Th
42、e purging unit shall be capable of continuous operation under any of the conditions specified in 3.7.1 and 3.7.2, for periods of not less than 24 hours without requiring shutdown for servicing, maintenance, or repairs. 6 Provided by IHSNot for ResaleNo reproduction or networking permitted without li
43、cense from IHS-,-,-I 7 . *-i . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-3.7.4 Environmental conditions. The purging unit shall withstand the follow- ing envirpnmental conditions without detrimental effect to subsequent operation: a. Storage in
44、 ambient temperatures ranging from -80“ to +160F. (See 4.6.8.1.1) b. Operation in ambient temperatures ranging from -65“ to +130F. (See 4.6.8.1.2) c. (See 4.6.8.3) Relative humidity up to 95 percent at a temperature of 130F d. Fungus growth as encountered in tropical and subtropical climates, (See 4
45、.6.8.4) e. Exposure to salt atmosphere as encountered in coastal areas. (See 4.6.8.5) . f. Rainfall as encountered in any locale. (See 4.6.8.6) g. Sand and dust particles as encountered in desert areas. (See 4.6.8.7) 3.8 Details of components. 3.8.1 Blower. of delivering oil-free air (see 6.3.2) to
46、the heater consistent with the requirements of 3.7.1. The components of the blower requiring oil such as bearings, gears, et cetera, shall be separated from the compression chamber of the assembly to insure delivery of oil-free air to the heating unit. The blower shall be a rotary or centrifugal-typ
47、e unit capable 3.8.1.1 Electric drive motor and power transmission coupling. The blower shall be driven by the electric motor and power transmission assembly specified in 3.8.2.2 and 3.8.2.2.3, respectively. .If practicable, direct drive shall be used. 3.8.1.2 Cooling system. necessary to maintain t
48、he blower components at suitable operating temperatures under all environmental conditions specified herein. The blower shall have an air-cooled system if 3.8.1.3 Blower lubricant. The blower shall be capable of complying with the oil-free requirement of 3.8.1 when operated with conventional hydroca
49、rbon lubricants. 3.8.2 Power unit, 3.8.2.1 Electrical equipment. Electrically powered equipment shall be of the explosion-proof type designed for use in group D atmospheres and class 1, divi- sion 2 hazardous locations in accordance with Pamphlet 70. Electrically powered equipment shall be designed, constructed, and installed in accordance with the National Electrical Manufacturers Association standards and Pamphlet 70. 8 Provided by I
