1、AMENDMENT 1 14 March 1983 i c MILITARY SPECIFICATION PERISCOPES, TANK: 11747126 AND .11747127 This Amendment forms a part of Military Specification MIL-P-48566(MU), dated 9 April 1976, and,is approved for use by the U.S. Army Armament Research and Development Command, and is available for use by all
2、 Departments and Agencies of the Department of Defense. PAGE 2 .Add Paragraph 3.6.1 as follows: I “3.6.1 Sealing. The Periscope equipped with purging valve, without the head assembly, shall show no evidence of leakage in excess of 0.1 psi/hour at 5 + 0.25 psig internal pressure using dry . nitrogen
3、gas having a dew poht of -250 or lower. also be purged and filled with ry nitrogen gas.“ The unit shall Add Paragraph 4.6.6.1 as follows: “4.6.6.1 Sealing. For Periscope equipped with purging valve. The nitrogen gas used for this test shall conform to Federal Specification BB-N-411, Type 1, Grade B,
4、 Class 1. Prior to performing the sealing test, the internal atmosphere of the Unit shall be tested utilizing the internal pressure testing apparatus of Drawing F8565556 together with a ew point tester. Attach the internal pressure testing apparatus to one purging port and the dew point tester to th
5、e other purging port. Apply an internal pressure of 1.0 to 2.0 psig (.O7 to -14 kg/cm2) of nitrogen gas to the periscope assembly while simultaneously capturing the initial exhaust of gas. exhausted gas from the unit shall conform to the requirements of 3.6.1, as measured with the dewpoint tester. S
6、ubsequent to this test, the sealing test of the unit shall be performed. The internal pressurizing to test the sealing of the unit shall be performed using the special testing equipment conforming to Drawing F8565556. The unit shall be pressurized to the re.quirements of 3.6.1 in The dew point of th
7、e initial amount of the FSC 1330 1 of 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I NIL-P-48566 4Jh.R) AMENDMENT 1 accordance with the internal pressure -test procedure delineated on Sheets 1 of 2 of Drawing F8565556. The pressure shall be reta
8、ined for the time period specified. Any evidence of leakage at the end of the minimum time period shall not exceed the tolerance specified in 3.6.P, .as measured on the -monitoring pressure gages of the testing equipment. Should leakage of the wit exceed the tolerance specified in 3.6.1, the unit sh
9、all be considered defective and shall be rejected. A record of beginning and sndiiyg 1ocal.atmospheric pressure and temperature shall be kept. Corrections torthe gage reading shall be made based upon any changes in these variables. Temperature changes shall be measured to an .accuracy of -+ - Oa5OF,
10、 pressure changes to 2 0.2“ Hg. NOTE: will produce an increase of 0.04 psi in the gage reading. increase of 0.1“ Hg of atmospheric pressure will produce a decrease of 0.05.psi in the gage reading.“ An increase of POF in the internal temperature of the unit An Custodian: Army-AR Preparing activity: I Army-AR .Project 13 30-A1 14 ) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
