1、MIL-V-5525C 16 7777906 OL47LIO 7 I- l MILv-5525C 21 OCTOBER 1959 SUPERSEDING MJL-V-5525B (ASG) 9 APRIL 1953 MLITARY SPECIFICATION VALVES, AIRCRAFT POWER BRAKE This specfieat2on has been approved by the Depmtment of Defense and b man- datory fol. me by the Depwtments of the Amy, the Navy, and the Air
2、 Force. 1. SCOPE 1.1 This specification covers power brake valves for use in aircraft hydraulic wheel brake subsystems up to a maximum rated pressure of 3,000 psi. 2. APPLICABLE DOCUMENTS 2.1 The following documents, of the issue in effect on date of invitation for bids, form a part of this specific
3、ation: SPECIFICATIONS MILITARY MIGP-5514 - Packings ; Installation and Gland Design, Hydraulic (Gen- eral Specification for). MIGP-5517 -Plastic Parts in Air- craft Hydraulic Equipment ; General Tests for. MIGH-5606 - Hydraulic Fluid, Pe- troleum Base, Aircraft and Ordnance. MIL-H-8775 - Hydraulic S
4、ystem Components Aircraft, General Specifi- cation for. STANDARDS MILITARY MIGSTD-105 - Sampling Procedures and Tables for Inspection by Attri- butes. (Copies of specifications, standards, drawings, and publications required by contractors in connection with specific procurement functions should be
5、ob- tained from the procuring activity or as directed by the contracting officer.) 3. REQUIREMENTS 3.1 Preproduction sample. Prior to begin- ning quantity production, preproduction sa- ples shall be subjected to preproduction test- ing. The preproduction sample shall be pro- duced by the same method
6、 and of the same material that will be used for quantity pro- duction of the item. 3.2 General. The requirements of Specifi- cation MIL-H-8775 apply as requirements of this specification with the exceptions and additions specified herein. When the two spe- cifications conflict, this specification sh
7、all govern. Unless othehise specified by the procuring activity, the brake valves shall not be used with any hydraulic fluid other than that conforming to the requirements of Specification MILH-5606. A Licensed by Information Handling ServicesProvided by IHSNot for ResaleNo reproduction or networkin
8、g permitted without license from IHS-,-,-3.3 Travel, load,-and pressure. Full plunger travel shall give maximum pressure at the brake $ortof- the valve. The pressure versus travel curve -shall be as shown on the applic- able specification control drawing. The exact requirements of pressure, load, an
9、d travel shall be governed by the brake system re- quirements. The pressure application and release curves shaEl be: smooth-with a mini-. mum indication of binding, sticking, or er- ratic action. . , 3.4 Performance. .The. power brake assem-. blies shall satisfy the performance tests spe- cified in
10、section 4 under paragraphs headed as follows : (a) Proof pressure- .(b) Bwt *pressure (d ) Endurance (fj Immersion !. . , (ci Leakage ._. ,(e) Pressure compensation - (g) Extreme temperature operation . . (4.7.3) . (47.4) . (4.7.5) . (4.7,6) (4.7.7) (4.7.1.1) (4.7.8) -* 3.5 Markings. All ports shall
11、 be clearly and permanently marked to facilitate identifica- tion. 4 QUALITY ASSURANCE PROVISIONS . . 4.1 Unless otherwise specified herein, the supplier is responsible for the performance of all inspection requirements prior to submis- sion for Government inspection and accept- ance. Except as othe
12、rwise specified, the sup- plier may utilize his own facilities or any com- mercial laboratory acceptable to the Govern- ment. Inspection records of the examinations pd tests shall be kept complete and available to the Government as specified in the contract gr order. *. 4.2 General. The Quality assu
13、rance provi- sions of Specification MIL-H-8775 shall apply as quality assurance provisions of this speci- fication with the exceptions and additions specifled herein. When the two specifications conflict, this specification shall govern. r. . - 4.3 Ciassification of tests. The inspection and testing
14、 of power brake valves shall be classified as follows : (a) Preproduction tests (see 4.4) (b) Acceptance tests (see 4.5) 4.4 Preproduction tests. . 4.4.1 Sczmpling ktruct2ons. The preproduc- tion test samples shall consist of two power brake valves of each size upon which approval is desired. One of
15、 the samples shall be assem- bled of parts LVE BRAKI;: 03 SIIZJLATED RXCORDITJG GAGE (IF AN ACTUAL-BRAKE rs USED RATHER THAN A SIPIULATED BRAKE, THE ACTUAL BRAU3 SHALL BE SUPPORTED O? UBOR CENTER3D IN TEE DRUM) FIGURE 1. Typical perjomnce and pressure compensation test setup I I Provided by IHSNot f
16、or ResaleNo reproduction or networking permitted without license from IHS-,-,-I ,MIL-V-5525C 1b 7777706 0184744 4 MIGV-5525C LEVER IN BRAKE OFF POSITION BRAKE VALVE FIGURE 2. Brake port and reservoir pmt proof pTessure test acts against a spring-loaded piston. When fluid displacement specified herei
17、n has been reached, the pis- ton will rest against a stop. The simulated brake shall have, as nearly as possible, the loadstroke characteristic of the brake used in the system for which the valve is being tested. 4.7.2.3 Output pressure and load. With the brake PO. connected to a pressure gage and 3
18、,000 psi applied to the pressure port, the brake valve shall be actuated to obtain 100 percent of plunger travel or as specified in the applicable specification control drawing. Brake pressure and plunger load shall be with- in the limits specified for the valve on the de- sired performance curve or
19、 on the accepted performance of prototype units. With the brake part connected to return through a flow- meter and a metering valve, the valve shall be set in order that at maximum brake pressure rated flow occurs; then the lever shall be oper- ated smoothly from maximum pressure to zero pressure an
20、d return several times. The flow how- ever, the valve between the accumulator and the brake valve shall be so closed that 2 to 10 psi is applied to the brake valve. The system shall then be allowed to stand for at least 24 hours at a temperature not higher than -54“ C (- 65“ F) if the brake valve co
21、n- tains nonmetallic parts other than standard packing installed in accordance with Specifica- tion MIL-P-5514 or inert plastics. In the event that no nonmetallic materials, other than standard packing installed in accordance with Specification MIGP-5514 os inert plastics are used, this time may be
22、reduced to 4 hours. During the soaking period, there shall be no external leakage, and inteinal leakage, as not- ed at the return port, shall not exceed that permitted by the detail specification or draw- ing. Pressure shall then be applied to the brake valve inlet port and allowed to remain on for
23、at least 15 minutes. There shall be no evidence of external leakage, and internal leak- age, as noted at the return port, shall not ex- ceed that specified in 4.7.5. At the end of this period, the brake valve shall be actuated to the 1111 on position and allowed to remain thus for 1 hour. The force
24、required for full brake application shall not exceed 110 percent of that required at normal tempemture, and the pressure at the brake port shall be the full rated pressure of the valve tested. During this period, there shall be no externai leakage, and internal leakage, is noted at the return port,
25、shall not exceed that swified in 4.7.5. The . the unit under test shall be removed from the cold chamber to outside room temperature and allowed to warm rapidly. When the external temperature reaches 4“ C (40 F) sucient actuations of the brake valve shall be made to prove that no binding exists in t
26、he unit throughout the fast warmup period. Leakage tests shall also be accomplished during this period, and leakage shall not exceed that per- mitted at - 54“ G (- 65“ FI. 4.7.8.3 High ternpemture operation, The brake valve shall be tested for binding, leak- age, and other malfunctioning at a temper
27、a- ture of 71“ C (160“ F) or higher under the conditions specified in 4.7.8. This test may be run at the termination of the immersion period or any other convenient time so long as the assembly remains at the specified temperature long enough to insure that the entire unit, in- cluding the fluid, is
28、 at the elevated tempera- ture. During this test, there shall be no evi- dence of binding or other malfunctioning. The leakage at 49“ C (120“ F) shall be not more than the leakage permitted at room tempera- ture, and the leakage at temperature above 49“ C (120“ F shall be not more than twice that pe
29、rmitted at room temperature). 4.8 Packing, packaging, and marking. The inspector shall ascertain that the packing, packaging, and marking of the brake valves conform to the requirements of section 6. 5. PREPARATION FOR DELIVERY 5.1 The provisions contained in section 5 of Specification MIL-H-8775, a
30、s applicable, shall form a part of this specification. 6. NOTES 6.1 Intended use. The hydraulic power brake valves covered by this specification brake valve shall then be re turne d. the “off“ aie intended for use in aircraft hydraulic position and the brake port pressure shall be brake systems as c
31、overed by Specifications reduced to O psi. MIL-H-5440 and MILB-8584. 4.7.8.2 Operatm and the fact that the Government may have formulated, furnished, or in any way supplied the said drawings, specifications, or other data is not to be regarded by implication or otherwise as in any manner licensing t
32、he holder or any other person or corporation, or conveying any rights or permission to manufacture, use, or seli any patented invention that may in any way be related thereto. Custodians a Army-Transportation Corps Navy-Bureau of Aeronautics Air Force Preparing activity: Naw-Bureau of Aeronautics *u. s. GOVERNMENT PRINTING OFFICE: s2isae-ioso-tv.4s) 9 48 -9: I-. . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
