MIL-DTL-24416 Extinguishing System, Fire, Fixed, Wet ChemicalThis specification covers requirements for pre-engineered wet chemical fixed fire extinguishing systems for protection of deep fat fryers, and doughnut fryers onboard U.S. Navy ships and submarines. The systems covered under this specification are intended for use in new applications, and for backfit into existing wet chemical extinguishing system installations. The current wet chemical extinguishing system utilizes aqueous potassium carbonate \(APC\) extinguishing agent, in a concentration of 42.4 percent K2CO3 and 52.8 percent water.

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MIL-DTL-24416C(SH)

3.4.9 Discharge nozzles. Discharge nozzles shall be in accordance with the wet chemical fire extinguishing

system configuration for which NFPA approval was granted. Discharge nozzles shall be constructed of a non-

combustible corrosion resistant material acceptable for use in food service zones.

3.4.9.1 Protective device. Discharge nozzles shall be provided with caps, covers, or other suitable protective

devices to protect nozzle from clogging by grease or other obstructions. Protective device shall detach upon

actuation.

3.4.9.2 Strainers. Strainers shall be installed at each nozzle to prevent foreign matter inside the distribution

piping from clogging the nozzle orifice.

3.4.10 Remote actuation devices. Remote actuation devices shall be provided for the manual actuation of the

extinguishing system. Remote actuation devices shall not require a force of more than 40 lbs or a movement of

more than 14 inches to operate. Remote actuation devices shall be provided with operating instructions.

3.4.11 Cable sections/actuating cable assembly. A cable and conduit assembly with corner pulleys, or sealed

ball bearing control cable are suitable for connection of the system actuation components including, remote manual

actuation device, fusible links, and the extinguishing agent release mechanism.

3.4.11.1 Cable. Actuating cable shall be installed enclosed in conduit. Cable shall be of sufficient tensile

strength, diameter, and material composition to withstand the pressure of the taut extinguisher release mechanism

system which includes fusible link detectors, extinguishing agent release mechanism, and remote manual actuation

device. Cable shall not bind at any point in the conduit or corner pulley. Cable conduit shall be installed so that

conduit runs cannot be moved out of their proper installed alignment.

3.4.11.2 Corner pulley. Corner pulleys shall be used whenever the cable requires a directional change of 90

degrees. Grease-tight corner pulleys shall be used in areas likely to experience excessive grease deposit build-up.

3.4.11.3 Actuating cable assembly. A sealed ball bearing control cable is acceptable for the connection and

actuation of the actuating system components. The ball bearing control cable shall consist of CRES races and

guides separated by two rows of CRES balls bearing, sealed in a flexible CRES sheathing. A potted steel cable

(both ends) connects the control cable to the actuation components including, remote manual actuation device,

fusible links, and the extinguishing agent release mechanism.

3.4.12 Distribution piping and fittings.

3.4.12.1 Material. Distribution piping and fittings shall be made of CRES piping or tubing.

3.4.13 Recharge apparatus. Recharge apparatus, fittings, and adapters shall be provided for recharging

extinguishing agent cylinders and expellant gas cylinders.

3.4.14 Color. Cylinders, control boxes, and enclosures shall be painted with red enamel in accordance with

color number 11105 of FED-STD-595.

3.4.15 Tools. No special tools shall be required for installation or maintenance of the system. Special tools are

defined as those tools not listed in the General Services Administration (GSA) Global Supply Catalog.

3.5 Performance characteristics.

3.5.1 Actuation requirements. Actuation from separation of fusible link detectors or operation of the remote or

local manual actuators shall result in discharge of the extinguishing agent.

3.5.2 Extinguishing agent requirements. Extinguishing agent shall perform in accordance with requirements of

UL 300 and NFPA 17A. When applied to flammable liquid surfaces, the extinguishing agent shall completely

extinguish the fire by creating a foam blanket barrier between the flammable liquid and oxygen and provide cooling

to the fat reservoir.

3.5.3 Discharge nozzle requirements. Discharge nozzles shall uniformly distribute the extinguishing agent over

and into the protected appliance in accordance with NFPA 17A when tested in accordance with 4.5.4.