1、Comments, suggestions, or questions on this document should be addressed to Defense Logistic Agency Aviation VEB, 8000 Jefferson Davis Highway, Richmond, VA 23297-5610 or emailed to STDZNMGTdla.mil. Since contact information can change, you may want to verify the currency of this address information
2、 using the ASSIST Online database at https:/assist.daps.dla.mil. AMSC N/A FSC 6685 MIL-DTL-25308C 1 November 2010 Superseding MIL-G-25308B 2 December 1971 DETAIL SPECIFICATION GAGE, PRESSURE, DIAL INDICATING, HYDRAULIC, TYPE ME-1 1. SCOPE 1.1 Scope. This specification covers the requirements for one
3、 type of hydraulic, dial indicating, pressure gage, designated type ME-1. 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 rec
4、ommended 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 of documents cited in sections 3, 4, or 5 of this specification, whether or not they are listed. 2
5、.2 Government documents. 2.2.1 Specifications, standards, and handbooks. The following specifications, standards, and handbooks of the exact revision listed below form a part of this document to the extent specified herein. INCH-POUND Inactive for new design after 9 March 1999. Provided by IHSNot fo
6、r ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25308C 2 FEDERAL STANDARD FED-STD-595/37038 - Black, Flat or Lusterless FED-STD-595/37875 - White, Flat or Lusterless DEPARTMENT OF DEFENSE SPECIFICATIONS MIL-DTL-5541 - Chemical Conversion Coatings on Aluminum and
7、Aluminum Alloys MIL-PRF-6085 - Lubricating Oil: Instrument, Aircraft, Low Volatility MIL-S-7742 - Screw Threads, Standard, Optimum Selected Series: General Specification for MIL-A-8625 - Anodic Coatings for Aluminum and Aluminum Alloys MIL-B-27497 - Bearing, Jewel, Sapphire or Ruby, Synthetic MS2810
8、5 - Cover Glass, Aircraft Instrument Dial MS33639 - Cases, Instrument, Clamp-mounted, Aircraft DEPARTMENT OF DEFENSE STANDARDS MIL-STD-130 - Identification Marking of U.S. Military Property MIL-STD-810 - Environmental Engineering Considerations and Laboratory Tests MIL-STD-810B, Notice 1 - Environme
9、ntal Test Methods, dated 20 October 1969, method 514.1 Vibration test only MIL-STD-810B - Environmental Test Methods, dated 15 June 1967 and including corrections of Notice 4 dated 21 September 1970, method 504 Temperature-Altitude test only MIL-STD-889 - Dissimilar Metals DEPARTMENT OF DEFENSE HAND
10、BOOKS MIL-HDBK-781 - Reliability Test Methods, Plans, and Environments for Engineering Development, Qualification, and Production MIL-HDBK-831 - Preparation of Test Reports (Copies of the above documents are available from the Standardization Documents Order Desk, 700 Robbins Avenue, Building 4D, Ph
11、iladelphia, PA 19111-5094 or online at https:/assist.daps.dla.mil.) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25308C 3 2.3 Non-Government publications. The following documents form a part of this document to the extent specified herein.
12、 Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract. SAE INTERNATIONAL AEROSPACE SAE AMS-QQ-P-416 - Plating, Cadmium (Electrodeposited) SAE AS5202 - Port or Fitting End, Internal Straight Thread, Design Standard (Copies of SAE documents are avai
13、lable from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001 or on-line at www.sae.org.) 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 (except for related spec
14、ification sheets), 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 Materials. 3.1.1 Nonmagnetic materials. Nonmagnetic materials shall be used for all parts of
15、 the gage except where magnetic materials are essential. 3.1.2 Nonferrous materials. Nonferrous materials shall be used for all parts of the gage except where ferrous materials are essential. 3.1.3 Metals. Metals shall be corrosion-resistant or suitably treated to resist corrosion due to fuels, salt
16、 fog, or atmospheric conditions likely to be met in storage or normal service. 3.1.4 Dissimilar metals. Unless suitably protected against electrolytic corrosion, dissimilar metals shall not be used in intimate contact with each other. Dissimilar metals are defined in MIL-STD-889. 3.1.5 Toxic and cor
17、rosive fumes. The gage shall be of such material and construction that fumes, when burned, or gases that combine with the atmosphere to form acid or corrosive alkali will not be liberated. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25308
18、C 4 3.1.6 Protective treatment. When materials are used in the construction of the gage that are subject to deterioration when exposed to climatic and environmental conditions likely to occur during service usage, they shall be protected against such deterioration in a manner that will in no way pre
19、vent compliance with the requirements of this specification. The use of any protective coating that will crack, chip, or scale with age or extremes of climatic or environmental conditions shall be avoided. 3.1.7 Fungus proof materials. Materials that are nutrients for fungi shall not be used where i
20、t is practical to avoid them. Where used and not hermetically sealed, they shall be treated with a fungicidal agent acceptable to the procuring activity. 3.2 Design and construction. The gage shall be designed to indicate directly the pressure in aircraft hydraulic and pneumatic systems. The gage sh
21、all be so constructed that no parts will work loose in service and shall be built to withstand the strains, jars, vibrations and other conditions incident to shipment, storage, installation and service. 3.2.1 Pivots, bearings and gears. Pivots, bearings and gears shall neither bind nor shake and sha
22、ll be as frictionless as practicable. 3.2.2 Adjustment mechanism. When the gage is so designed as to permit adjustment, it shall be provided with a means for adjusting or correcting the indications which shall be simple to manipulate and so designed that adjustments can be made without the use of sp
23、ecial tools. The means of adjustment need not be outside the case. 3.2.3 Separate mechanism. The gage mechanism shall be comprised of units distinct from the case. The gage shall be sufficiently rugged that small distortions of the case will not affect accuracy of the indication. 3.2.4 Reliability.
24、The gage shall have a minimum acceptable mean-time-between-failures (MTBF) of 2,000 hours based upon a discrimination ratio of 1.5 and a confidence factor of 90 percent. 3.3 Performance. The gage shall operate satisfactorily after subjection to the following conditions: a. Temperatures operating tem
25、peratures ranging from -54C to +100C (-65F to +212F) and non-operating temperatures ranging from -65C to +145C (-85F to +293F). b. Vibration vibration of 2g from 5 to 500 Hz. c. Temperature-altitude pressure altitude of 100,000 feet at -55C (-67F). d. Salt fog exposure to salt sea atmosphere for 48
26、hours without evidence of corrosion or deterioration. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25308C 5 e. Humidity relative humidity to 95 percent. f. Fungus fungus growth as encountered in tropical climates. g. Dust exposure to dry d
27、ust-laden atmosphere. h. Overpressure overpressure of 5,000 pounds per square inch (psi) 3.3.1 Tolerances. The gage shall operate within the tolerances specified in tables I and II. TABLE I. Scale error tolerance, psi. Test Pressure (psi) Dust Room temp. Salt fog Humidity Low temp. operation Low tem
28、p. exposure High temp. operation Altitude Vibration High temp. exposure 0 50 75 100 500 50 100 125 1,000 50 100 125 1,500 50 100 125 2,000 50 125 150 2,500 50 125 150 3,000 50 125 150 3,500 75 125 150 4,000 75 125 150 TABLE II. Test Pressures and tolerances. Test Test Pressure (psi) Tolerance (psi)
29、Friction error all tests - 75.0 Position error 2,000 30.0 Overpressure 5,000 80.0 + room temp tol Seasoning - 20.0 + room temp tol Vibration Pointer oscillation Pointer variation 2,000 100 100 3.4 Part numbering of interchangeable parts. All parts having the same manufacturers part number shall be f
30、unctionally and dimensionally interchangeable. 3.5 Case. The case shall consist of a body and a bezel ring and shall conform to figure 1. The case body shall be made of either nonferrous, low-density metal or of a synthetic material, shall be uniform in texture and shall have a smooth surface. The b
31、ezel and that part of the case visible from the cockpit side of the instrument panel shall be finished in lusterless black per FED-STD-595, color 37038. The remainder of the case may be finished in black and shall be adequately Provided by IHSNot for ResaleNo reproduction or networking permitted wit
32、hout license from IHS-,-,-MIL-DTL-25308C 6 protected to satisfactorily withstand the environmental conditions specified herein. Synthetic material shall be of a thermal-setting type composed of a suitable filler and phenal condensation product binder. 3.6 Mounting nuts. When attached insert nuts are
33、 used, each mounting lug shall be fitted with #6 (0.138 inch)-32 UNC-2B self-locking insert nuts which shall be so attached as to prevent loosening under an axial load of 25 pounds (lbs) and prevent turning under a torque of 10 inch-pounds (in-lbs). 3.7 Boss. The boss on the gage shall conform to SA
34、E AS5202-04. Flats shall be provided on the side of the boss for a minimum distance of 0.375 in. to permit the use of a wrench to tighten the mating fitting. 3.8 Cover glass. The cover glass shall be in accordance with MS28105. The thickness shall be the minimum practicable and entirely suitable for
35、 the purpose. 3.9 Dial to cover glass distance. The distance between the inner surface of the cover glass and the dial shall be the minimum practicable and shall not exceed 0.125 in. 3.10 Cover glass to edge of case distance. The distance between the outer surface of the cover glass and the front ed
36、ge of the case shall be the minimum practicable and shall not exceed 0.031 in. 3.11 Pointer. The pointer shall conform to figure 2. 3.11.1 Pointer finish. The visible portion of the pointer shall be lusterless white per FED-STD-595, color 37875. 3.12 Overpressure stop. An overpressure stop shall be
37、provided to restrain the prime mover and to prevent disengagement of the pinion and sector gears during service use and under the test conditions specified herein. The stop shall allow the pointer to travel beyond full scale and to a point within 10 from the horizontal centerline of the dial. 3.12.1
38、 Range marks. Two range marks of lusterless black per FED-STD-595, color 37038 shall be located 10 on either side of the horizontal centerline on the right-hand side of the dial. 3.13 Dial. The dial shall conform to figure 1 and shall be constructed of metal. The minimum diameter across the outside
39、ends of the graduation marks shall be 1.75 in. The 2,000 psi graduation shall be located on the horizontal centerline at the left side of the dial. If screws are used to fasten the dial, they shall be located on the horizontal centerline of the dial. Provided by IHSNot for ResaleNo reproduction or n
40、etworking permitted without license from IHS-,-,-MIL-DTL-25308C 7 3.13.1 Markings. The markings shall be as specified in table III. Unless specified, the location of the markings are optional. TABLE III. Marking details. Height or length, in. 0.016 Width of line or Graduation, in. 0.005 Color Per FE
41、D-STD-595 Numerals, 0, 1, 2, 3, 4 0.156 0.025 37875 Major graduations 0.188 0.031 37875 Minor graduations 0.094 0.020 37875 Lettering “HYD PRESS” 0.125 0.025 37875 Lettering “PSI X 1000” 0.094 0.020 37875 Lettering :”USAF TYPE ME-1” 0.063 37038 Dial face 37038 All other markings 37038 3.14 Screw thr
42、eads. Unless otherwise specified, screw threads shall be in accordance with MIL-S-7742. 3.15 Lubricants. Lubricants shall conform to MIL-L-6085. 3.16 Weight. The weight of the gage shall not exceed 0.5 lbs. 3.17 Jewel bearing. When synthetic sapphire or ruby bearings are used, they shall conform to
43、MIL-B-27497. 3.18 Finishes and protective coatings. 3.18.1 Aluminum-alloy parts. Aluminum alloy parts shall be covered with an anodic film conforming to MIL-A-8625, except as follows: 3.18.1.1 Dials, small holes and inserts. Dials, small holes, and case inserts need not be anodized. 3.18.1.2 Non-ano
44、dizable alloys. Aluminum alloys which do not anodize satisfactorily shall be coated with a chemical film in accordance with MIL-C-5541. 3.18.1.3 Paint base. Where the primary purpose of the treatment is to afford a suitable paint base, chemical treatments in accordance with MIL-C-5541 may be used in
45、 lieu of anodizing. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-25308C 8 3.18.1.4 Non-aluminum inserts. Castings containing non-aluminum integral inserts may be treated with a chemical film in accordance with MIL-C-5541 may be used in lie
46、u of anodizing. 3.18.1.5 Abrasion resistance. When abrasion resistance is a factor, parts shall be anodized. 3.18.2 Steel parts. Cadmium plating of steel parts, when used, shall be in accordance with AMS-QQ-P-416, type II or III, as applicable, and of a class that is adequate to achieve the degree o
47、f protection required. 3.19 Identification of product. Equipment, assemblies and parts shall be marked for identification in accordance with MIL-STD-130. 3.20 Workmanship. The gage shall be constructed and finished in a thoroughly workmanlike manner. Particular attention shall be given to neatness a
48、nd thoroughness of soldering, wiring, marking of parts and assemblies, and freedom of parts from burrs and sharp edges. 3.20.1 Dimensions. Dimensions and tolerances not specified shall be as close as is consistent with best shop practices. Where dimensions and tolerances may affect the interchangeab
49、ility, operation or performance of the gage, they shall be held or limited accordingly. 3.20.2 Gears. Gear assemblies shall be properly aligned and meshed and shall be operable without interference, tight spots, loose spots or other irregularities. Where required for accurate adjustments, gear assemblies shall be free of backlash. 3.20.3 S
