1、16 JUNE 1964 SUPERSEDING MIL-V-6129 18 MAY 1950 MILITARY SPECIFICATION VhW, CHECK; VACUUM AND PRESSURE SYSTEM ThEs apecificatoon has been approved by the DepartmenC of Defenae ami is man- datory for uae by the Departments of tle Army, the Navy, and the Air Force. * 1. SCOPE MIL-P-7936 - Parts and Eq
2、uip- * 1.1. This specification covers one type of air check valve. ment, Procedures for Packaging of, MIL-D-70327 - Drawings, Engineer- ing and Associated * 2. APPLICABLE DOCUMENTS * 2.1. The following documents, of the Lists. issue in effect on date of invitation for bids or request or proposal, fo
3、rm a part of this specification to the extent specified herein : MILITARY *SPECIFICATIONS MIL-STD-105 - Sampling Procedures and Tables for In- FEDERAL spection by Attri- butes. MIL-STD-129 - Marking for Ship- MILITARY ment and Storage. MIL-P-116 - Preservation, Meth- MIL-STD-130 - Identification Mar
4、k- ing of U. S. Mili- tary Property. MIL-C-5501 tective, Duat and MIL-STD-I43 - Specifications a n d Moisture Seal. Standards Order PPP-B-636 - Box, Fiberboard. ods of, - Caps and Plugs, Pro- MIL-S-7742 - Screw - T h r e a d s; Standard, O p t i - of Precedence for The Selection of. mum. Selected MS
5、28050 - Valve, Check, Low Series, G e n e r a 1 Pressure, Internal Specification For. Threads, Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-V-b324A Li8 W 999490b 0270833 5 W MIL-Vl29A MS93586 .- Metals, Definition of oration in a manner that w
6、ill in no way prevent compliance with the performance requirements of this specification. Protec- * (Copies of specifications, standards, drawings, and tive coating which might crack, chip or scale during normal service life or under demes of environmental conditions shall not be Dimimilar. publicat
7、ions required by auppliera in connection with specific prociirenient functions should be obtained from tho prociiring activity or as directed by the contracting officer). 3. REQUIREMENTS * 8.1. Selection of specifications and standards. - Specifications and standards for necessary commodities and se
8、rvices not specified herein shall he selected in accord- ance with Standard MIL-STD-143. * 32 Materials. Materials shall conform to applicable specifications and shall be as specified herein and on applicable drawings. Materials which are not covered by specifi- cations, 01 which are not specificall
9、y de- scribed herein, shall be of the best quality, o the lightest practicable weight, and suit- able for the purpose intended. * 3.2.1 Metal parts. All metal parts shall he of corrosion resistant material or treated in a maimer to render them adequately re- &itant to corrosion. The use of magnesium
10、 or its alIoys ia prohibited. * 3.3 Design and construction. The de- sign and construction of the air check valve shall be in accordance with Standard MS28050 with the applicable drawings specified in the contract or order (see 6.2). The flapper hinge shall be provided with a spring having sufficien
11、t force to return the flapper to its closed position, when the valve is held in any position. with no air flow. The air check valve shall be designed so that no parts will work loose in service. It shall be built to withstand the strains, jars, vibrations and such other conditions as are incidental
12、to shipping, storage, installation, and service. * 3.3.1 Threads. Only Clam 3 straight threads conforming to Specification MIL&- 7742 shall be used. * 3.3.2 Locking. The screws and nuts used in assembiing the air check valve shall be locked in place. Lock washers shall not be used. 3,2.2 Nottrunetii
13、c materials. Nonmag- netic materials shall be used for all parts of the valve except where magnetic ma- terials are essential, * 3*2.3 Protmtive treatment. When ma- terial% are tised in the construction of the air cheek valve that are subject to deteriora- tion when exposed to environmental condi- t
14、ions likely to occur during service usage, they shall be protected against such deteri- 2 * 3.5 Interchangeability. All parts hav- ing the same manufacturers part number shall be functionally and dimensionally in- terchangeable. The drawing number re- quirements of Specification MIL-D-70327 shall go
15、vern changes in the manufacturers part number. * 3.6 Weight. The weight of the air check valve shall not exceed the value specified on Standard MS28050. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MLL-V-6129A * 3.7 Markings. Markings shall be dur
16、able to withstand usage encountered in service. * 3.7.1 Direction of flow shall be indi- cated by arrows in two places approxi- mately 180 degrees apai-t as shown in the drawings. *. * 3.8 Identification of product. The air check valve shall be marked for identifica- tion in accordance kith Standard
17、 MIL- S TD-13 O. * 3.9 Worknianship. The air check valve shall be uniform in quality and shall be free from irregularities, defects or foreign matter which could adversely affect safety, performance, reliability, or durability. * 4. QUALITY ASSURANCE PROVISIONS * 4.1 Responsibility for inspection. U
18、n- less otherwise specified in the contract or purchase order, the supplier is responsible for the performance of all inspection re- quirements as specified herein. Except as otherwise specified, the supplier may utilize his own facilities or any commercial labo- ratory acceptable to the Government.
19、 The Government reserves the right to perforin any of the inspections set forth in the speci- fication where such inspections are deemed necessary to assure supplies and services conform to prescribed requirenents. * 4.2 Classification of inspection. All the inspections of the air check valve shall
20、be classified as quality conformance inspection. * 4.3 Quality con8 ormance inspection. The quality conformance inspection shall consist of individual inspection and sam- * 4.3.1 Individual inspection. .Each air check valve on the contract or order shall be subjected. to the following inspection in
21、the order listed. Any air check valve con- taining a defect or failing to pass any of these tests shall be rejected. pling tests. . _I ,-. . . .t. . -. . r. . ., , - (a) Examination .I . (4.5.1) (b) Leakage (4.5.5) * 4.3.2 Sampling inspection. A random sample shall be selected from each inspec- tion
22、 lot in accordance with Standard MIL- STD-105, at inspection level S2 and shall be subject to the following tests. If a sam- ple fails to pass any of these tests, the lot represented by that sample shall be rejected. The tests shall be performed in the order listed. The valves should be examined aft
23、er each test for signs of deterioration or im- pending failures. (a) Deterioration (4.5.2) (b) . Durability (4.5.3) (c) Pressure Drop . (4.5.4) (cl) Leakage . (4.5.2) (e) Magnetic Effect . _. (4.6.6) * 4.3.2.1 Inspection lot. All air check valves of the same size offered for delivery at one time sha
24、ll be considered a lot for purposes of inspection. * 4.4 Test condition. Unless otherwise specified, tests shall be conducted at ambient temperature of 77 -C 18“ F and. at an am- bient barometric pressure of 28 to 32 inches of mercury. * 4.5 Inspection methods, * 4.5.1 Exammtzon. The air check valve
25、 shall be thoroughly examined to determine conformance with this specification and ap- plicable drawings with respect to all the re- quirements not covered by tests. * 4.5.1.1 The air check valve shall be ex- amined to ascertain that the preparation for delivery conforms to this specification. * 4.5
26、.2 Deteroration. 3 . Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MLV4129A * 4.5.2,l The air check valve shall be im- merged in tap water for a 12 hour period. All internal parta of the air check valve shall be ia contact with the fluid during the
27、 immemioii. After the test there shall be no evidence of deleterioilu effect3 to any part of the air check vnlvc. with its axis in a vertical position, with the inlet port down. The pressure drop through the air check valve shall be determined at the applicable maximum air flow specified in Table I.
28、 The pressure drop of the air check valve shall not exceed the applicable maximum permissable pressure drop speci- fied in Table I. * 4.5.2.2 The air check valve shall be im- mersed in commercial kerosene for a 12 hour period. All internal parts of the air check valve shall be in contact bith the fl
29、uid during the immereion. After the test there shall be no evidence of deleterious effects to any part of the air check valve. * 4.5.3 DicrcbNtp. The valve shall be opened ancl closed 2000 times. After the test there shalI be no evidence of malfunc- tion, mechanical failure or deformation. * 4.5.4 P
30、r*csmie drop. The air check valve shall be tested for pressure drop with its axis in a horizontal position and again 4.5.5 Leakage. * 4.5.5.1 InZet port. The air check valve shall be tested for leakage with a vacuum applied to the inlet port in such a way as b hold the flapper closed. The pressure r
31、e- quired to close the flapper shalI be noted. “he leakage rate shall be determined with cz suitable air-flow meter connected between the outlet port and the atmosphere to meas- ure the air-fiow into the valve. The leak- age rate shall not exceed the applicable specified maximum permigsible leakage
32、rate ia Table I. The flapper shall close under a differential pressure of 24 inches of water. Performance Tokaneer - _- Mkumiilll Permbsibk Mufmom I Pambsfble -Drop Lenkaps Bat4 I sir0 Rattnir of vm Alr Flow f cfm of free rir eimoffrfdr NO OD under rkl ssa Incha Water midustdra levei condition# -I-
33、_ I I krrl amdithna - - -I -1 1/4 I . 0.50 3.75 0.10 -6 1 3/8 2.00 3.75 0.10 1- - - - - i 6.00 3.75 0.10 518 10.00 4.25 I 0.10 I 0.10 -* -16 I 1 I 20.00 4.75 I I _ -8 -10 I - - i x-tiag 13 tpsd on air-flw which duce a preisum dnp of 0.10 inch Of macan In 1 foot of Imfi af tubing rfre OD (Stinnrtl 31
34、628Q50) by 0.036 Wall ThWrnwr. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-* 4.5.5.2 Outlet port. The valve shall be tested for leakage with a vacuum applied to the outlet port:and -with the inlet port plugged. A vacuum of IO inches of mercury sh
35、all be appIied to-theotlet port and then pinched off. The change in manometer level shall not exceed 0.20 inch of mercury in 10 seconds. * 4.5.6 Magnetic eftect. The magnetic property of the valve shall be determined in terms of the deflection of a free magnet, approximately IV2 inches long, in a ma
36、g- netic field with a horizontal intensity of 0.18 Gauss. The valve shall be held mag- netically east or west of and 5 inches from the center of the magnet. The deflection of the compass shall be noted. The deflection shall not exceed 5 degrees. (An aircraft compass with compensating magnets re- mov
37、ed therefrom may be used as the free magnet for this test.) 5. PREPARATION FOR DELIVERY. * 5.1 The valve shall be prepared for de- livery in accordance with Specification MIL-P-7936. Preservation for Level A shall be in accordance with Specification MILP-116, Method 1C-3, without the use of contact
38、preservatives and without clean- ing by immersion in solvent. * 5.1.1 Plugs. Pork shall be sealed by closures conforming to Specification. MIL- c-5501. * 5.2 Packing. Packing shall be in ac- cordance with Specification MIL-P-7936, Level A, B or C as specified in the contract or order (see 6.2). Exte
39、rior containers shall contain identical quantities and as far as practical shall have the minimum cube and tare consistent with the protection re- quired. * 5.2.1 Level A. Air check valves pack- aged as in 5.1 shall be packed in snug fitting fiberboard containers conforming to Speci- fication PPP-B-
40、636, Class 2. Containers shall be closed and sealed as specified in the appendix of Specification PPP-B-636. * 5.2.2 Level B. Ais check valves pack- aged as in 5.1 shall be packed in snug fitting fiberboard containers conforming to Speci- fication PPP-B-636, Class 1 Containers shall be closed and se
41、aled as specified in ap- pendix of Specification PPP-B-636. . * 5.3 Marking and labeling. Marking shall conform to MIL-STD-129. 6. NOTES 6.1 Intended use. The valves covered by this specification are intended for use in connection with vacuum and pressure systems to limit the air-flow to only one di
42、rection. * 6.2 Ordering data. Procurement docu- ments should specify the following: (a) Title, number, and date of this specification. (b) Selection of applicable levels of preservation, packaging and packing required, (c) Quantity and size of valve re- quired. (d) Samples subjected to destructive t
43、ests are not to be considered os shipped as part of the contract or order. * 6.3 The outside margins of this speci- fication have been marked to indicate where changes (deletion, additions, etc.) from the previous issue have been made. This has been done as a convenience only and the Government assu
44、mes no liability whatsoever for any inaccuracies in these notations. Bidders and contractors are cautioned to evaluate the requirements of this document based on the entire content as written ir- respective of the marginal notations and relationship to the last previous issue, Provided by IHSNot for
45、 ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-V-bLZ9A YB U 97999Ob OZ79835 2 MIL-V-6 129A iustodian: Preparing Activity: Naey-WI Navy-WP Air Force-11 DOD Project No. 4820-0039 Review Intereat: Navy-WP Air Force-11 6 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
