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

Class 2 - 12273264

Class 3 - 12314511

3.3.2.2 Dip or siphon tube. Unless otherwise specified (see 6.2), dip or siphon tubes

shall not be used (see 4.4.1).

3.3.2.3 Receiver cylinder. The receiver cylinder shall meet the requirements of DOT 3A

or 3AA of 49 CFR, Sections 178.36 or 178.37, and shall be tested according to the cited CFR

and the non-shatterability requirements of MIL-DTL-7905, or equivalent. The receiver cylinder

shall withstand a service pressure of 12,410 kPa (1800 psi) (see 4.4.1).

3.4 Operating requirements.

3.4.1 Discharge valve.

3.4.1.1 Manual discharge. The manual release mechanism shall open the valve and

discharge the extinguishant in response to a force of 65 to 115 Newtons (N) [14.6 to 25.8 pound-

force (lbf)] from a flexible cable or similar actuator. The mechanism shall function within the

travel limits specified on Drawing 12370477. Clearance shall be provided within the valve

envelope to allow both push and pull activation of the manual release lever. A means shall be

provided whereby manual valve function may be locked by insertion of a safety pin release lock

conforming to Drawing 12288692 or Drawing 12343165 (see 4.4.2.1.1).

3.4.1.2 Electrical release. The valve shall begin to discharge Halon 1301 within 10 ms

after receiving the activation signal specified in 3.3.1.1.9.3 with 28 volt direct current (Vdc) step

input at room temperature, 25�8 �C (77�14 �F). The valve shall complete discharge of the liquid

phase of Halon 1301 within the time limits of table II. After discharge, the residual agent

content shall not exceed 1.5 percent (%) by weight of the initial charge. The residual pressure in

the extinguisher shall not exceed 345 kPa (50 psi) at all temperatures between -51 and 71 �C (-60

and 160 �F). The valve shall operate at all voltages between 16 and 30 Vdc (see 4.4.2.1.2 and

6.4.2).

TABLE II. Discharge time.

Extinguisher class

Maximum discharge time

135 ms

190 ms

270 ms

3.4.1.3 Fragmentation. The valve shall not eject any solid metallic or nonmetallic

fragments larger than 300 micrometers (m) (0.012 in.). The total number of ejected particles

between 50 and 300 m (0.002 and 0.012 in.) shall not exceed the requirements of

IEST-STD-CC1246, chart 1, level 300, or equivalent. Injury to personnel shall be of primary

concern. Partial or complete blockage of discharge valve nozzles or distribution tubes shall not

occur from ejected fragments (see 4.4.2.1.3).