SENTRY Carbon Dioxide Hand Portable Fire Extinguishers
Operation, Inspection, Service and Maintenance,
and Recharge Manual (Part No. 429425)
PAGE 12 REV. 05 2018-OCT-11
SERVICE AND REPAIR
SERVICE AND REPAIR (Continued)
COMPONENT DISORDER
CORRECTIVE ACTION
Cylinder
Dents or abrasions*
Hydrotest (See Form No. T-2017001, Hydrostatic Test
Instructions) or discard cylinder.
Rust spots, pits, corrosion*
Clean affected area. Replace if there is any corrosion
penetration.
Threads nicked, cross-
Clean threads with a stiff bristle brush. If damaged or
threaded, corroded or worn
worn, discard cylinder.
Valve
Leak at safety nut
Remove nut, disc and washer. Clean out receptacle. Replace
with new components. Torque to 17 ft-lb to 20 ft-lb (23.2 N•m to
27.1 N•m).
Leak through valve outlet
Discharge. Disassemble valve. Replace plunger stem.
Leak at plunger stem
Discharge. Disassemble valve. Replace plunger stem.
(Under operating lever)
Leak at hose joint
Disassemble and examine internal and external threads.
Replace hose if damaged.
Leak at hex swivel/valve joint
Disassemble. Clean seating surface. Reassemble.
(5 lb extinguisher only)
Assure tube rotates freely but not loosely.
Leak at cylinder/valve joint
Examine for cracks around perimeter of cylinder neck. Discard
if cracks are found. If leaking at thread joint, remove valve from
cylinder. Clean threads with stiff brush. On aluminum shell only,
replace O-ring. On steel shell only, lightly lubricate valve thread
with DOW 111 or equal and reinstall valve. Torque steel shell
to 50 ft lb (68 Nm). Tighten aluminum shell hand tight.
Sticky valve
Disassemble valve. Examine valve stem and push lever.
Replace if damaged. Replace stem O-ring and adequately
lubricate.
Nameplate
Unreadable
Use a mild detergent to clean plate. If readability cannot be
improved, replace nameplate.**
Loose
Inspect under plate. If corroded, see ‘‘Cylinder-Rust spots, pits
and corrosion’’ and reaffix nameplate using a good grade of
heatless adhesive.
Missing
Replace with new nameplate.**
Hose
Cut, cracked or abraded
Replace hose assembly.
Corroded or cracked coupling
Replace hose assembly.
Internal blockage
Clear by flexing or blowing air or nitrogen through hose at 50
psi (3.5 bar) or less. Replace if blockage cannot be removed.
CAUTION
Do not leave open end of hose unattended unless
adequately restrained to prevent whipping.
Horn
Cracked
Replace horn.
* Refer to Compressed Gas Association (CGA) pamphlets C-6 and C-6.1.
** Replacement maintenance nameplates from Johnson Controls will not have a UL manifest.
