1、 flIL-PRF-8932B E 9999906 2072657 891 = I INCH-POUND I 27 August 1998 SUPFERSEDING 12 August 1980 MIL -PW- 8 93 2B MIL-S-8932A PERFORMANCE SPECIFICATION SWITCHES, PRESSURE, BULKHEAD MOUNTED, AIRCRAFT, GENERAL SPECIFICATION FOR This specification is approved for use by all Departments and Agencies of
2、 the Department of Defense. 1. SCOPE 1.1 Scope. This specification covers the requirements for aircraft pressure actuated electrical switches. 1.2 Classification. Pressure switches covered by this specification are of the following classes as specified (see 6.2). 1.2.1 Classes. Class 1 - Absolute pr
3、essure switch (see 6.3.2). Class 2 - Differential pressure switch (see 6.3.3). Class 3 - Gauge pressure switch (see 6.3.4). Class 4 - Approximate gauge pressure switch (see 6.3.5). comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document
4、should be addressed to: Commander, Naval Air Warfare Center Aircraft Division, Code 4141 OOB 120-3, Highway 547, Lakehurst, NJ 08733-5100, by using the Standardization Document Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter. AMSC NIA FSC 1650 DISTRIBUTION STAT
5、EMENT A. Approved for public release; distribution is unlimited. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-8932B 9999906 2072658 728 MIL-PRF-8932B 2. APPLICABLE DOCUMENTS . 2.1 General. The documents listed in this section are specified
6、 in sections 3 and 4 of this specification. This section does not include documents 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 this list, document users are cautioned that they
7、 must meet all specified requirements documents cited in sections 3 and 4 of this specification, whether or not they are listed. 2.2 Government documents. 2.2.1 SDecifications and standards. The following specifications and standards form a part of this document to the extent specified herein. Unies
8、s otherwise specified, the issues of these documents are those listed in the issue of the Department of Defense Index of Specifications and Standards (DoDISS) and supplement thereto, cited in the solicitation (see 6.2). SPECIFICATIONS DEPARTMENT OF DEFENSE MIL-PRF-5624 - Turbine Fuel, Aviation, Grad
9、es JP-4, JP-5, and JP-S/JP-8ST MIL-PRF-83282 - Hydraulic Fluid, Fire Resistant, Synthetic Hydrocarbon Base, Metric, NATO Code Number H-537 MIL-PRF-87257 - Hydraulic Fluid, Fire Resistant; Low Temperature, Synthetic Hydrocarbon Base, Aircraft and Missile STANDARDS DEPARTMENT OF DEFENSE MIL-STD-130 -
10、Identification Marking of US Military Property MIL-STD-704 - Aircraft Electric Power Characteristics MIL-STD-8 1 O - Environmental Test Methods (See supplement 1 for list of specification sheets and MS sheets) (Uniess otherwise indicated, copies of the above specifications and standards are availabl
11、e fkom the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19 1 1 1-5094.) 2.3 Order of precedence. In the event of a conflict between the text of this document and the references cited herein (except for related associated specifications or specification sheet
12、s), the 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-8932B text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 3. REQUIREMEN
13、TS 3.1 Specification sheets. The individual item requirements shall be as specified herein and in accordance with the applicable specification sheet. In the event of any conflict between the requirements of this specification and the specification sheet, the latter shall govern. 3.2 First article. W
14、hen specified (see 6.2), a sample shall be subjected to first article inspection in accordance with 4.2. 3.3 Materials. Materiais shall be compatible with fuel and hydraulic fluids conforming to MIL-PRF-5624 and MIL-PRF-83282 or MIL-PRF-87257. 3.3.1 Non-mwnetic materials. Non-magnetic materials shal
15、l be used for all parts of the switch. 3.3.2 Metals. Metals shall be corrosion resistant or protected from corrosion. If materials other than metals are used, they shall be treated to resist corrosion. Materiais having finishes and coatings which can crack, chip or scale due to fuels, salt spray, or
16、 atmospheric conditions to which the switch may be subjected in storage or during normal service life shall not be used. 3.3.2.1 Dissimilar metals. Where dissimilar metals are used in contact with each other protection shall be provided (see 6.7). 3.3.2.2 Electrical contact parts. The electrical con
17、tact parts shall carry the electrical loads specified in the applicable specification sheets. 3.3.2.5 Mamesium allov parts. Magnesium alloy parts shall not be used. 3.3 -2.6 Recvcled. recovered, or environmentally ureferable materials. Recycled, recovered, or environmentally preferable materials sho
18、uld 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. 3.3.3 Fungus proof materials. Materials which are nutrients for fungi shall not be used. 3.4 Characteristics.
19、The external switches shall conform to the dimensions shown on figure 1 and the applicable specification sheets. The manufacturers discretion shall govern the internal design of the switch. 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-. MIL-PRF-
20、8932B 3.4.1 Adiustments. Switches shall be provided with means of adjustment. Means of adjustments shall be externally accessible and shall be designed to meet the requirements specified in table I of the applicable specification sheets. All adjustments shall be provided with a locking mechanism for
21、 securely locking them after initial adjustments have been made to prevent loosening due to jars, strains, vibrations, and other conditions incident to shipping, storage, installation, and service. All adjustment mechanisms shall be designed in such a way that adjustment can be made without damaging
22、 the hermetic seal of the switch case. Switch shall be set at the factory during manufacture to the switching point(s) as specified in the applicable specification sheets. 3.4.1.1 Pressure adiustment. Switches shall provide means for accurately adjusting the actuation or deactuation of the switch va
23、lve or similar device. The adjustment shall incorporate a recessed slot or hex socket, which shall be filled with a potting compound. The switch shall be completely adjustable throughout the specified range so that the operating setting at which the switch operates, shall be set anywhere within the
24、pressure range and tolerances specified in the applicable specification sheets. 3.4.2 Pressure ports. Pressure ports for all switches shall be provided. When a separate port is required for the case pressure release, it shall interface with a connecting adapter. 3.4.3 Switch case. The switch case di
25、mensions shall be as shown on figure 1 and the applicable specification sheets (see 6.2). The case shall be hermetically sealed and the switch case design shall be such that the internai mechanisms shall be able to be removed from the case, replaced, and the case resealed. Switches designed for norm
26、al system pressures (see 6.3.6) above 150 pounds per square inch gauge (psig) shall incorporate a pressure release valve. 3.4.4 Weieht. The maximum weight of the completely assembled switch, without fittings, mounting bolts, nuts, screws, and clamps shall be not greater than the maximum weight speci
27、fied in the applicable specification sheets. 3.4.5 Port location and dimensions. The location and dimensions of the switch ports shall be in accordance with figure 1 and the applicable specification sheets. 3.4.6 Soldering;. Low temperature solders shall not be used in joints where failure would per
28、mit the escape of the fluid actuating the switch. 3.4.7 Electrical characteristics. 3.4.7.1 Number of contacts. The pressure sensing mechanism shall operate either two or four contacts (one or two sets) as required in the applicable specification sheet. 4 Provided by IHSNot for ResaleNo reproduction
29、 or networking permitted without license from IHS-,-,-MIL-PRF-8932B 3.4.7.2 Voltage. The switches shall operate in aircraft electrical systems in which the applied voltage does not exceed the limits specified in MIL-STD-704, Category B. 3.4.7.3 Current rating. The maximurn current ac or dc rating of
30、 the switch shall be as specified in the applicable specification sheets. 3.4.7.4 Relays. Relays shall not be used inside the switch case. If a relay is incorporated in the circuit design, it shall be located in such a manner that it is totally independent of the switch case. 3.4.7.5 Electrical conn
31、ector. The electrical connector shall mate with MS3443. The electrical connector used shall be in accordance with figures 1 and 2 of the applicable specification sheet. 3.4.8 Finish. Protective coatings and finishes, shall not crack, chip, or scale during normal service life or from extreme atmosphe
32、ric conditions. 3.5 Performance. 3.5.1 Examhation. When examined as specified in 4.5, the switches shall meet the dimensional requirements of this specification and the applicable specification sheets. 3.5.2 Proof messure and drift. When subjected to the proof pressure and drift test as specified in
33、 4.6.1, the switches shall operate within the tolerances specified in table 1 of the applicable specification sheets. 3.5.3 Dielectric strength. The switch shall withstand 500 vac. When tested as specified in 4.6.2, there shall be no breakdown of insulation or any permanent damage to the switch as a
34、 result of the test. 3.5.4 Leakage. When tested as specified in 4.6.3, the detected leakage shall be not greater than O. 1 -micron cubic foot per hour at one atmosphere. 3.5.5 Repeatability. When tested as specified in 4.6.4, the pressure at which the switches actuate and deactuate shall be not grea
35、ter than the tolerances specified in the applicable specification sheets. 3.5.6 Operating messure range. When tested as Specified in 4.6.5, the switches shall be within the operating range as specified in the applicable specification sheets. 5 Provided by IHSNot for ResaleNo reproduction or networki
36、ng permitted without license from IHS-,-,-MIL-PRF-8932B 9999906 2072662 159 MIL-PRF-8932B 3.5.7 Operating differential (see 6.3.7). When tested as specified in 4.6.6, the difference between the actuation and deactuation values (reference values) shall be not greater than the tolerances specified in
37、the applicable specification sheets. 3.5.8 Position. When tested as specified in 4.6.7, the reference values shall be not greater than the tolerances specified in the applicable specification sheets. 3 S.9 Room temperature endurance. When tested as specified in 4.7.1, the operating points shall not
38、differ from the reference values by more than the tolerances specified in the applicable specification sheets. 3.5.10 High temperature operation. When tested as specified in 4.7.2, the high temperature operating points shall not differ from the reference values by more than the tolerance specified i
39、n the applicable specification sheet. 3.5.1 1 Low temperature operation. When tested as specified in 4.7.3, the operating points shall not differ fi-om the reference values (see 6.3.8) by more than the tolerance specified in the applicable specification sheet. 3.5.12 Vibration. When tested as specif
40、ied in 4.7.4, there shall be no opening of closed contacts or closing of open contacts during the test. At the conclusion of the test, the switch shall be electrically operative without damage to the internal parts. 3.5.13 Shock. When tested as specified in 4.7.5, there shall be no opening of closed
41、 contacts or closing of open contacts during the test. At the conclusion of the test the switch shall be electrically operative and there shall be no damage to the internal parts. 3.5.14 Salt spray. When tested as specified in 4.7.6, there shall be no evidence of corrosion. 3.5.15 Burst pressure. Wh
42、en tested as specified in 4.7.7, there shall be no evidence of leakage. 3.5.16 Proof pressure. The proof pressure of the switch case shall be 75 5 psi. When tested as specified in 4.7.8, there shall be no evidence of valve leakage or damage to the valve. 3.5.17 Endurance. When tested as specified in
43、 4.7.9, the switch contacts shall break a power load and the operating pressures shall not differ fiom the reference values by more than the tolerances specified in the applicable specification sheet. 3.5.18 Case pressure release. A device to discharge excessive case pressure shall be provided in ea
44、ch pressure switch within the pressure ranges of 0-500 psi to O-5,000 psi. This device shall operate to release the internal case pressure through an orifice whenever the internal case pressure, relative to 6 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from I
45、HS-,-,-MIL-PRF-8932B m 9999906 2072663 095 MIL-PRF-893 2B the atmosphere, reaches 90 i 30 psi. If a metal blowout device is used it shall not damage hermetic sealing. When tested as specified in 4.7.1 O, the case pressure release device shall operate at a pressure of 90 i 30 psi. There shall be no d
46、amage to the switch or leakage from the switch case. 3.5.19 fil lin medium. The filling medium shall contain not more than .O06 milligram of water vapor per liter (dew point 45 OC) at the filling pressure. The absolute pressure of the filling medium in the case shall be 1 .O k O. 1 atmosphere. 3.6 W
47、orkmanshb. The switch, including all parts and accessories, shall be constructed and finished to produce an item fi-ee fi-om all defects, which would affect proper functioning in service and freedom from burrs and sharp edges. 4. VERIFICATION 4.1 Classification of inspections. The inspection require
48、ments specified herein are classified as follows: a. First article inspection (see 4.2). b. Conformance inspection (see 4.3). 4.2 First article inspection. The first article inspection consists of examinations and tests (see table I). The sample shall be representative of the design, configuration,
49、and performance of the switches which shall be produced on the manufacturers production line. 4.2.1 First article inspection sample. First article inspection samples shall consist of three switches manufactured in accordance with this specification (see 6.2). 4.3 Conformance insDection. Conformance inspection shall consist of examinations (see table I) performed in the order listed. 4.3.1 Sampling for conformance inspection. a. Sampling plan A b. Sampling plan B
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