1、Y. - MIL-T-8427B 47 7797906 02q3802 b =. - - MIL-T-8429B 11 JUL 83 SUPERSEDING MIL-T-8429A(USAF) 29 May 1957 - .- leakage; demand oxygen regulator, type MH-2 5 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-T-LI29B 97 7777706 OZi3807 5 W MIL-T-
2、8429B FIGURE 2. Tester, leakage, demand oxygen regulator, type MH-2 (dimensions in inches) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NIL-T-i-129B 47 W 997970b 02i-13808 7 W MIL-T-8429B 3.7.5 Adapters. The adapters for connecting the tester to o
3、xygen regula- tors shall be as shown in Figure 1. directly to the tester to regulator tubing and the second adapter shall be secured to the end of the tubing by means of a small, flexible chain conform- ing to RR-C-271, type II, class 6. The stopper shall be a commercial No. 2 rubber stopper The oth
4、er adapter shall conform to-Figure 3, The stopper type shall be connected 3.7.6 Case. The case shall be fabricated from 0.062 inch aluminum con- The top shall be hinged to the body of A handle for carrying the case forming to QQ-A-250/8F, temper H34. the cae. cover closed when the tester is not in u
5、se. shall be provided on the top of the case. The cover shall be provided with a suitable latch for holding the 3.7.6.1 Finish. The case shall be given one coat of zinc-chromate primer, conforming to TT-P-1757 prior to painting. the case shall be painted with two coats of lacquer conforming to TT-L-
6、32. The color of the lacquer shall conform to No. 17038 of FED-STD-595. After the primer is thoroughly dry, 3.8 Weight. The weight of the complete tester shall not exceed 6 pounds. 3.9 Identification of product. The tester shall be marked in accordance with MIL-STD-130. 3.10 Operating instructions.
7、The operating instructions shall be securely attached to the inside of the case cover, positioned as shown in Figure 1, and placed on an easily replaceable card. The instructions shall be as follows: 1. Plug hose with connector from MH-2 tester into female connection of regulator hose, and close rel
8、ief valve on bulb. 2. Test of A-12, A-l2A, A-13, A-14, A-15, A-21, D-1, D-2, D-2A, MB-2, MD-1, or MD-2 regulators: (a) Squeeze bulb until pressure gage reads 17 inches of water and squeeze bladder to hold pressure. Leakage flow gage should not read more than 1.0 liter per minute on “normal“ nor more
9、 than 0.5 liter per minute on “100 percent. I (b) 3. If leakage is excessive, repeat test with tester, plugged into regulator outlet. If leakage is still excessive, regulator is defective; if it is no longer excessive, hose is defective. 4. If leakage exceeds the maximum allowable leakage, remove re
10、gula- tor for repair. Rework tag should read, “Removed for excessive outward leakage. To check the MH-2 tester, close end of stopper with finger and squeeze bulb until pressure gage reaches 17 inches of water pressure. the tester is operating satisfactorily. 5. A reading of zero on the leakage flowm
11、eter indicates 7 o Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-T-8429B 49 9797906 0243809 9 .- MIL-T-8429B FIGURE 3. Adapter f 8 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-T-8429B 6.
12、If it is impossible to reach 17 inches of gage pressure and according to test 5, above, tester is operating satisfactorily, the regulator is leaking excessively and should be removed for repair. 7. To test regulator technical order compliance with pressure breathing outlet pressures, read outlet pre
13、ssure in inches of water on testers pressure gage while the regulator is set as specified in the applicable. technical ordex, 3.11 Interchangeability. All parts having the same manufacturers part number shall be directly and completely interchangeable with each other with respect to installation and
14、 performance. bers shall be governed by the drawing number requirements of DOD-D-1000. Changes in manufacturers part num- 3.12 Workmanship. The tester shall be constructed in accordance with high-grade aircraft instrument manufacturing practice. thoroughly cleaned of all oil and foreign matter and f
15、ree from any defects that might affect its operations or functionability. The tester shall be 4. QUALITY ASSURANCE PROVISIONS 4.1 Responsibility for inspection. Unless otherwise specified in the con- tract of purchase order, the contractor is responsible for the performance of all inspection require
16、ments as specified herein. Except as otherwise speci- fied in the contract or purchase order, the contractor may use his own or any other facilities suitable for the performance of the inspection requirements reserves the right to perform any of the inspections set forth in the specifi- cation where
17、 such inspections are deemed necessary to assure supplies and ser- vices conform to prescribed requirements. - specified herein, unless disapproved by the Government. The Government 4.1.1 Classification of tests. The inspection and testing of testers shall be classified as follows: a. Acceptance tes
18、ts (see 4.2). b. Preproduction testing (see 4.3). 4.2 Acceptance tests. Acceptance test shall consist of: a. Individual tests. b. Sampling tests. 4.2.1 Individual tests. Each tester shall be subjected to the following tests as described under Test Methods of this specification: a. Examination of pro
19、duct. b. Flow measuring gage. c. Pressure gage. d. Leakage. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-T-84298 49 W 79999060243811 7 W MIL-T-8429B 4.2.2 Sampling plan and tests. 4.2.2.1 Sampling plan. One tester shall be selected at random f
20、rom each lot of 100 testers, or fraction thereof, and, subjected to the following tests: a. Overload. b. High and low temperature operation. c. Shock. 4.2.2.1.1 Rejection. When one tester from a lot fails the specified tests, this is cause for rejection of the lot. Before resubmitting the lot, the c
21、on- tractor shall fully explain to the inspector both the corrections made and the cause of previous rejections 4.3 Preproduction testing. 4.3.1 Preproduction test sample tested by the contractor. The contractor shall subject one tester to the preproduction tests specified in 4.3.4. 4.3.2 Preproduct
22、ion test report. After the contractor completes the pre- production tests, he shall prepare a preproduction test report according to MIL-STD-831 and furnish three complete copies of this report to the Government activity specified in 6.3. 4.3.3 Preproduction test sample for the Government procuring
23、activity. Along with the preproduction test report, the contractor shall submit one sam- ple to the Government activity specified in 6.3. 4.3.4 Preproduction tests. Preproduction tests shall consist of all tests described under test methods. 4.4 Test conditions. 4.4.1 Atmospheric conditions. Unless
24、otherwise specified, all tests re- quired by this specification shall be made at an atmospheric pressure of 28 to 32 inches of mercury and at a temperature of 77 degrees Fahrenheit, plus or minus 18 degrees, and a relative humidity of 80 percent or less, Where tests are made with atmospheric pressur
25、e or temperature substantially different from the above values, proper allowances shall be made for the change in instrument reading. 4.5 Test methods. 4.5.1 Examination of product. Unless otherwise specified by the procuring activity, each tester shall be checked to determine compliance with this s
26、peci- fication with respect to materials, workmanship, finish, weight, and markings. 4.5.2 Flow measuring gage, The calibration of the gage shall be tested with orifice attached end at conditions of 4.4.1. A downstream pressure of 17 inches of water shall be applied and flow adjusted to O, 0.25, 0.5
27、0, 1.0, and 2.0 liter per minute as measured with an adjusted flow meter, Any gage indi- cating flows which vary more than the rate of plus or minus.1 percent based on full scale shall be rejected. I 10 i) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-
28、,-,-MIL-T-8429B 4.5.3 Pressure gage. The pressure gage shall be attached to a water mano- meter having a range from O to 30 inches of water. at 5, 10, 20, and 25 inches of water pressure. more than plus or minus three percent at any test points shall be rejected. The gage shall be tested Any gage in
29、dicating errors 4.5.4 Leakage. The rate of outward leakage through the tester shall be determined by applying 20 inches of water pressure internally to the tester, with the regulator adapter plugged, The rate of leakage shall be determined by the pressure drop within the system. Testers indicating a
30、 leakage in excessof 0.50 inch of water pressure drop per minute or a deviation of the flow measuring gage from zero (in accordance with Section 5 of 3.10, operating instructions), shall be rejected. 4.5.5 Overload. A mercury manometer with a range of at least O to 30 inches of mercury shall be atta
31、ched to the regulator adapter with the adapter plugged. The internal pressure shall be increased by means of the pressure bulb until a pressure of 3 inches of mercury is indicated on the manometer. This pressure shall be maintained for a period of 2 minutes. measuring gage and pressure gage shall in
32、dicate within the allowable error specified herein at the completion of this test when subjected to the indi- vidual tests. The flow 4.5.6 High and low temperature operation. The pressure gage and the differential flow gage shall be subjected to a temperature of plus 160 degrees Fahrenheit and minus
33、 65 degrees Fahrenheit, respectively, for a period of 2 hours. vided to each gage; any gage deviation of more than the rate of plus or minus one percent based on full scale shall be rejected. brated tester (as per4.5.2) shall continue to operate satisfactorily after being subjected to plus 160 degre
34、es Fahrenheit and to minus 65 degrees Fahren- heit for 2 hours. of tester. A means of supplying a known static half-scale reading shall be pro- The completed and cali- No flow measuring correction is necessary for requirements 4.5.7 - Shock. One complete tester shall be tested by dropping it on a co
35、n- Crete slab from a height of five feet. three paralleled to each of the three principal axes of the tester in order of back, top, and side. At the completion of the shock test, the gages shall be checked for calibration errors and examined for any evidence of damage to the internal parts. Any devi
36、ation from requirements of 3.6.8 shall be cause for rejection. This is considered a destructive test. Samples tested for shock shall not be submitted as part of the production order. this test, the tester shall be subjected to and meet 4.5.4. A total of 9 blows shall be applied, Upon completion of *
37、 5. PACKAGING * 5.1 Preservation and packaging. Preservation and packaging shall be level A, C or industrial in accordance with MIL-C-52211, as specified (see 6.2). * 5.2 Packing. Packing shall be level A, B, C or industrial in accordance with MIL-(2-52211, as specified (see 6.2). * 5.3 Marking. In
38、addition to any special marking required by the contract or order, unit packages, intermediate packages, and shipping containers shall be marked in accordance with the requirements of MIL-STD-129. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-T
39、-8427B 47 7977706 0243813 O MIL-T-8429B 5.3.1 Industrial. Industrial marking shall be in accordance with the requirements of MIL-STD-1188. 6. NOTES- 6.1 Intended use. This tester is intended for use in testing demand type oxygen regulators for outward leakage while installed in the aircraft. 6.2 Ord
40、erinP data. 6.2.1 Acquisition requirements. Acquisition documents should specify the f o1 low ing : a. Preproduction requirements. b. c. Unit quantities. Level of packing and packaging required. 6.3 Changes from previous issue. The margins of this specification are marked with asterisks to indicate
41、where changes (additions, modifications, corrections, deletions) from the previous issue were made. a convenience only and the Government assumes no liability whatsoever for any inaccuracies in these notations. Bidders .and contractors are caiitioned to . evaluate the requirements of this document b
42、ased on the entire content irre- spective of the marginal notations and relationship to the last previous issue. This was done as Custodians: Army - AV Air Force - 99 Preparing activity: Air Force - 82 ( Pro j ec t 49 20- O 187) 12 US. QOVERNMENT PRINTING OFFICE: 1983401-084/571 f- I- _ - Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
