MIL-DTL-62547 Valve And Cylinder Assemblies, Halon 1301This specification covers three classes of fixed fire extinguishers, referred to herein as "extinguishers", "valve and cylinder assemblies" and "assemblies", and an electrically and manually actuated discharge valve, referred to herein as "discharge valve" and "valve". These items are used with bromotrifluoromethane \(Halon 1301\) fire extinguishing systems in military vehicles \(see 6.1 and 6.2\).

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MIL-DTL-62547D

and the extinguisher filled with test liquid. Pressure shall be increased until the relief device

opens [not less than 18,300 kPa (2650 psi) or, more than 20,700 kPa (3000 psi)]. The pressure

shall be recorded.

4.4.2.1.4.2 Pressure indication device. To determine conformance to 3.4.1.4.2, the

following tests shall be conducted. The procedures of 4.4.2.2.4 shall be followed except that the

pressure indicator shall be installed and the pressure maintained at 20,700 kPa (3000 psi) for at

least five seconds. The pressure indicator shall not be damaged, and the pointer, (if used) shall

not be bent. Pressure shall then be returned to ambient. The extinguisher shall be drained and

dried, without cooling, by use of clean filtered air or nitrogen to remove residual moisture. The

extinguisher shall be rebuilt and instrumented with a master pressure gage. The extinguisher

shall be pressurized with nitrogen and cold soaked at 16 �C (5 �F) until the temperature stabilizes

as specified in 4.3.2.2. Nitrogen shall be released through the fill or vent valve until the pressure

reaches 3580 kPa (519 psi). The process shall be repeated at all pressures and temperatures

specified in 3.4.1.4.2.

4.4.2.1.4.3 Pressure switch. To determine conformance to 3.4.1.4.3, the valve shall be

installed on an instrumented cylinder and a charge shall be applied. At ambient pressure the

switch shall be in a normally open position and shall close during charging. Slowly release the

charge through the fill or vent valve and monitor the extinguisher pressure. As the charge is

released, the switch shall open between 2500 and 2200 kPa (363 and 319 psi). The pressure

recession curve shall be as indicated in figure 3.

4.4.2.1.5 Flow indication. To determine conformance to 3.4.1.5, the extinguisher shall

be set up as shown in figure 4. The extinguisher shall be activated by applying a 30 Vdc stop

input across the terminals of the discharge valve. Upon discharge, the flow indication device

shall open a normally closed circuit. A steady state flow indication signal shall be provided

within 5 ms after opening of the valve or the beginning of extinguishant flow. There shall be no

flow indication prior to the beginning of extinguishant flow or opening of the valve. This test

shall be repeated with 16 Vdc and may be conducted concurrently with the test of 4.4.2.1.2.

4.4.2.1.6 Quiescence.

4.4.2.1.6.1 Quiescent/continuity/resistance. To determine conformance to 3.4.1.6, the

resistance in the valve solenoid circuit and in the pressure/flow circuit shall be measured using a

current of less than 5 mA. The resistance shall not exceed 8 ohms.

4.4.2.1.6.2 Continuity/checkout current. To determine conformance to 3.4.1.6, the valve

shall be set up according to figure 5. For qualification testing the discharge valve shall be set up

to take a continuous current flow of 5 mA for not less than 240 hours without activation. This

test may run concurrently with 4.4.5.2.1.1. For quality checks the duration of this test shall be 15

to 30 seconds.