Amerex builds four different 125 lb wheeled ABC dry chemical extinguishers. The 488 is stored pressure. The 450 is pressurized at the moment of use by a 23 cubic foot nitrogen cylinder. The 467 and 470 draw from a 110 cubic foot nitrogen cylinder through a pressure regulator — and all that separates those two is 16-inch versus 36-inch wheels. Same capacity, same agent, four model numbers, three different valve systems.
That is why ordering wheeled unit parts by size and agent goes wrong. The valve lever that fits a 488 — part 06059, with screws — does not fit a 450, which takes the 06373 T-handle lever. Amerex's own Parts Book is built around this distinction: twelve parts lists, pages 15 through 26, belong to wheeled units, and no two models share a list unless they share a drive system. Identify the drive system first, and every part number after that falls into place.
The drive systems, and how to tell them apart
Stored pressure. The agent cylinder holds pressure at all times — a hand portable scaled up, with a gauge on the operating valve and no gas bottle on the carriage. The 50 lb 495 (ABC) and 497 (Purple K) ride on what Amerex calls "easy rolling 12½ inch semi-pneumatic rubber tires"; the 125 lb 488 and 490 use 16-inch wheels and carry a fill cap (09300). The 50 lb manual is specific about the gauge: "the pressure shall be in the green zone (240 psi ± approx. 10 psi range)" — and the 488/490 read the same 240 PSI gauge (05225-P) on their operating valve.
Nitrogen cylinder operated. The agent cylinder sits unpressurized until the moment of use. Amerex's operating instructions: "Remove pull pin and pull 'T' handle to open nitrogen cylinder valve. This will pressurize the extinguisher." Three gas cylinder sizes define three model families — 23 cubic feet on the 125 lb 450 and 452, 110 cubic feet on the 125 lb 467/469/470/472, and 55 cubic feet on the 300 lb 491 and 493. Amerex also rates the nitrogen cylinder units for −65°F to +120°F service, against the −40°F floor stated in the 50 lb, High Performance and Z-Series stored pressure manuals.
High Performance and Z-Series. Stored pressure again, but hotter — the gauge green zone is "350 psi ± approx. 15 psi range or 240 psi ± approx. 10 psi for 759." The Z-Series 756 (250 lb ABC) and 758 (250 lb Purple K) run at 350 psi; the 125 lb Purple K 759 and the galvanized 690 run at 240 psi. These are the offshore units: "Lift points are incorporated into the carriage frame so that these units can be easily on/off loaded at off-shore platforms or placed by a crane into remote areas in land based installations."
Wheeled CO2. The 333 (50 lb) and 334 (100 lb) carry no pressure gauge anywhere on their parts list — as Amerex's owner's manual puts it, "Carbon Dioxide extinguishers determine fullness by weighing or hefting." Discharge is controlled by a shut-off valve assembly (09366) at the horn rather than a ball valve on the hose.
Wheeled Class D. The 680 (150 lb sodium chloride) and 681 (250 lb copper) work like the nitrogen cylinder units but run on argon: "The gauge shall read approximately 2015 psi (13.9 mPa) at 70°F (21°C)" on the gas cylinder, and the agent is applied through a wand applicator.
Which agent belongs on the carriage is a separate question — our Purple K vs ABC guide compares the two agents hazard by hazard. This guide is about keeping the carriage working.
| Drive system | Models | Identify it by | Owner's manual |
|---|---|---|---|
| Stored pressure, 50 lb | 495 ABC · 497 PK | Gauge on valve, no gas bottle, 12½ in. tires, ½ in. × 25 ft hose | 05612 |
| Stored pressure, 125 lb | 488 ABC · 490 PK | Gauge on valve, fill cap, 16 in. wheels, ¾ in. × 50 ft hose | 05608 |
| Nitrogen cylinder, 23 cu ft | 450 ABC · 452 PK | Short nitrogen bottle, no regulator, 16 in. wheels | 05605 |
| Nitrogen cylinder, 110 cu ft | 467/470 ABC · 469/472 PK | Tall nitrogen bottle with 02235 regulator; 16 in. wheels (467/469) or 36 in. (470/472) | 05605 |
| Nitrogen cylinder, 55 cu ft | 491 ABC · 493 PK | 300 lb agent cylinder, 36 in. × 6 in. wheels, 1 in. × 50 ft hose | 05614 |
| High Performance / Z-Series | 756 ABC · 758, 759, 690 PK | Stored pressure at 350 psi (240 psi on 759/690), 36 in. wheels, lift points | 27085 · 05617 (690) |
| Wheeled CO2 | 333 (50 lb) · 334 (100 lb) | No gauge; horn with shut-off valve on a 40 ft hose | 05618 |
| Argon cylinder, Class D | 680 sodium chloride · 681 copper | Argon bottle, wand applicator, ¾ in. × 25 ft hose | 05620 |
The service parts the wheeled line shares
Amerex reuses hardware heavily across the wheeled families. These part numbers appear on multiple parts lists — here are the model groups above that each one serves.
| Part no. | Amerex's description | Serves |
|---|---|---|
| 06373 | "Valve Lever ('T' Handle - Complete)" | 495/497 · 450/452 · 467–472 · 491/493 · 333/334 · 680/681 |
| 06059 | "Valve Lever with Screws" | 488/490 · 756/758/759/690 |
| 12467 | "Nitrogen Valve with Gauge ('T' Handle Quick Release)" | 450/452 · 467–472 · 491/493 · 680/681 (listed there as the argon valve) |
| 02235 | "Nitrogen Pressure Regulator" | 467/469/470/472 only |
| 10213-P | "Gauge - 3000 PSI" | 450/452 · 467–472 · 491/493 · 680/681 |
| 05225-P | "Gauge - 240 PSI" | 495/497 · 488/490 · 690/759 |
| 07751 | "Wheel Assembly 16\" with Hub Cap, Washer and Retaining Pin (Semi-Pneumatic)" | 488/490 · 450/452 · 467/469 · 333/334 |
| 04945-P | "Hub Cap" | Every 12½ in. and 16 in. wheel in the line — 36 in. wheels take 16984 or 07389 instead |
| 06279 | "Ball Valve Assembly" | 488/490 · 450/452 · 467–472 · 491/493 · 756/758/759/690 · 680/681 |
| 03877-P | "Gasket, Hose and Nozzle" | Every dry chemical group plus 680/681 — the CO2 units are the exception |
| 16483 | "Bolt, Washer and Wing Nut" | 467–472 · 491/493 · 680/681 |
| 06809 | "Nitrogen Cylinder (55 cu. ft.) - Charged with Cap" | 491/493 |
The pattern worth memorizing: every gas-cylinder-operated unit — nitrogen or argon — uses the same 12467 T-handle cylinder valve, the same 10213-P 3000 PSI gauge, and the same 06373 discharge lever. The 125 lb and larger stored pressure families swap in the 06059 lever and an agent-side gauge instead — only the 50 lb 495 and 497 keep the 06373 lever on a stored pressure valve. Get the drive system right and one small parts shelf covers a mixed fleet.
Where the sharing stops
The 50 lb units are not small 488s. Below the carriage handle, the 495 and 497 go their own way: the discharge ball valve is 06031, not the 06279 used on every other dry chemical and Class D list; the hose gasket is 07247-P, with 03877-P appearing only at the nozzle; and the wheels are the 12½-inch 06377 assembly, not the 16-inch 07751 — only their 04945-P hub cap is shared.
Two hardware bags, one description. Amerex lists "Bolt, Washer and Wing Nut" twice: 16483 serves the 110 cu ft units, the 300 lb 491/493 and the Class D wheeled units, while the 23 cu ft 450 and 452 take 11970. The descriptions are identical; the part numbers are not interchangeable in the lists.
Class D shares the valve, not the regulator. The 680/681 argon cylinder uses the same 12467 valve and 10213-P gauge as the nitrogen units, but its pressure regulator is 10915 — the 02235 nitrogen regulator does not appear on that list.
Watch the R suffix on wheels. The Z-Series parts list carries the standard 36 in. × 6 in. Z-Series wheel assembly (27226) alongside a separate vulcanized rubber wheel (27071) assigned to the 756R, 758R and 759R. If your nameplate says 758R or 759R, order accordingly — our model number decoder covers what the suffixes mean.
One regulator, two gauges
Only one wheeled family uses a nitrogen regulator at all, and the service manual is direct about it: "The only regulator used on Amerex dry chemical regulated wheeled extinguishers is Victor Model Number 1333, Amerex PN# 02235." Regulated means the 110 cu ft models — 467, 469, 470, 472. The 23 cu ft 450/452 and the 55 cu ft 491/493 pressurize without a regulator, and Class D units take the 10915 argon regulator instead.
The gauges follow the same logic. The 10213-P 3000 PSI gauge reads the gas cylinder — Amerex's maintenance procedure calls for repressurizing the nitrogen cylinder when it reads "below 1700 psi (11.7 MPa)." The 05225-P 240 PSI gauge reads the agent cylinder on stored pressure units, with the 350 PSI 08714-P taking its place on the 756 and 758. A wheeled unit with a nitrogen cylinder needs the high-pressure gauge on the bottle; a stored pressure unit needs the low-pressure gauge on the valve; the CO2 units need neither. And when one of these units is discharged, our recharge guide matches the 06160 and 09857 wheeled fill adapters to the families they serve.
What we stock
Wheeled service parts — the drive-system hardware above, including the 06373 T-handle lever, 12467 cylinder valve, 02235 regulator, 06809 charged 55 cu ft nitrogen cylinder, 07751 16-inch wheel assembly and 16483 hardware bag — live in Wheeled Unit Parts, with the full gauge and valve range in Valves, Gauges & Downtubes. Hoses, nozzle tips, nameplates and pictograms for these models are in the wider service parts catalog, searchable by part number.
Complete wheeled units — wheeled ABC, wheeled Purple K, wheeled CO2 and wheeled Class D, spanning the stored pressure, nitrogen cylinder, Z-Series, CO2 and Class D drive systems above.
Finally, the 859 dolly cart shoppers keep finding is not a wheeled unit part — Amerex lists it under Miscellaneous Items, sized for 7- and 8-inch diameter cylinders. We stock it too.
Matching parts against a nameplate we haven't covered here? Send us the model and serial numbers and we'll confirm fitment, pricing and lead time — request a quote.
Sources
Part numbers, descriptions and fitment above are taken from the wheeled-unit parts lists in Amerex Corporation's Portable & Wheeled Parts Book, whose service-manual index also supplies the owner's manual numbers in the table. Operating specifications and quoted language come from Amerex owner's/service manuals PN 05612 (50 lb stored pressure wheeled), PN 05605 (125/150 lb nitrogen cylinder wheeled), PN 05614 (300/350 lb nitrogen cylinder wheeled), PN 05617 and PN 27085 (High Performance and Z-Series wheeled), PN 05620 (Class D wheeled) and PN 27794 (Owner's Manual, for the CO2 fullness check). Parts lists change between production years — confirm against your extinguisher's own nameplate and serial number and Amerex's current documentation before ordering, and have maintenance performed by a qualified fire protection professional in accordance with NFPA 10 and your authority having jurisdiction.
ShopAmerex.com is owned and operated by Centurion Holdings Group LLC, an independent authorized distributor of Amerex Corporation products. We sell equipment and factory OEM service parts — we do not perform inspection, service, hydrostatic testing or recharging.