ShopAmerex.com · Amerex 03785 datasheet · https://shopamerex.com/products/amerex-03785-nitrogen-tube-assembly-125-150-lb-wheeled-unit · Figures as published by Amerex · Verified Sep 2, 2026
Genuine Amerex service part·Part no. 03785
Amerex 03785 Nitrogen Tube Assembly, 125/150 lb Wheeled Unit
Amerex 03785 is the Nitrogen Tube Assembly listed as item 6 on printed page 18 (PDF page 20) of Amerex Parts Book 27277 Rev D, for 125/150 lb dry chemical wheeled models 450 (125 lb ABC) and 452 (125 lb Purple K). Full overview ↓
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Which models does the Amerex 03785 fit?
Per the Amerex Parts Book · page 20| Fits | Extinguisher | UL rating | Capacity | Price | Link |
|---|---|---|---|---|---|
| Model 450 |  11483 Amerex 450 125 lb Wheeled ABC Fire ExtinguisherParts Book p.18 |
30A:240B:C | 125 lb (57 kg) | $4,960.00 | View |
| Model 452 |  10643 Amerex 452 125 lb Wheeled Purple K Fire ExtinguisherParts Book p.18 |
320B:C | 125 lb (57 kg) | $6,671.00 | View |
Parts list for 125/150 lb. dry chemical wheeled models, 23 cu. ft. nitrogen cylinder
Fitment per the Amerex Parts Book. Check the part number against your unit’s nameplate before ordering.
What is the Amerex 03785?
Amerex 03785 is the Nitrogen Tube Assembly listed as item 6 on printed page 18 (PDF page 20) of Amerex Parts Book 27277 Rev D, for 125/150 lb dry chemical wheeled models 450 (125 lb ABC) and 452 (125 lb Purple K). It is the gas tube that carries nitrogen into the agent cylinder from the inlet port where the nitrogen hose connects. Manual 05605 builds a gas tube integrity check into annual maintenance: pressure or dry chemical agent leaking from that inlet port indicates a defective gas tube, and the agent cylinder must be emptied before the tube is replaced. The 300/350 lb wheeled models use a different tube, 06789.
Amerex 03785 specifications
| Part number | 03785 |
|---|---|
| Description | Nitrogen Tube Assembly |
| Parts Book page | Printed page 18 (PDF page 20) |
| Diagram item | 6 |
| Pack quantity | 1 (sold individually) |
| Models | 450, 452 |
|---|
| Amerex item number | 03785 |
|---|
Part data as published by Amerex. Confirm against the current Parts Book revision before ordering for a unit in service.
Amerex 03785 documents
Official Amerex publications · PDFCurrent Amerex publications, hosted on ShopAmerex so links do not break when Amerex reorganizes its site.
Other parts on Parts Book page 20
Parts list for 125/150 lb. dry chemical wheeled models, 23 cu. ft. nitrogen cylinder · All 11 parts| Part no. | Part | Pack | Price | Quantity and add to cart |
|---|---|---|---|---|
| 03784 | 1 (sold individually) | $126.00 | ||
| 03787-P001 | Pack of 1 | $200.00 | ||
| 03817 | Each | $1,188.00 | ||
| 03818 | 1 (sold individually) | $156.00 | ||
| 04072 | 1 (sold individually) | $30.99 | ||
| 06467 | 1 (sold individually) | $191.00 | ||
| 11970 | Each | $6.99 | ||
| 13956 | 1 (sold individually) | $4.99 |
Item numbers refer to the exploded view on the Parts Book page. Model-specific items are marked in the Amerex parts list; confirm before ordering.
Amerex 03785 questions
What does the Amerex 03785 nitrogen tube assembly fit?
Amerex 125/150 lb nitrogen cylinder wheeled dry chemical models 450 (125 lb ABC) and 452 (125 lb Purple K).
What does the nitrogen tube assembly do?
It carries nitrogen into the agent cylinder from the gas tube inlet port where the nitrogen hose connects, per manual 05605.
How do I know if the gas tube is defective?
Manual 05605's gas tube integrity check calls for briefly pressurizing the agent cylinder from a regulated nitrogen source; pressure or dry chemical agent leaking from the gas tube inlet port indicates a defective tube.
Does replacing it require emptying the agent cylinder?
Yes. Manual 05605 states that a defective gas tube requires that the agent cylinder be emptied and the tube replaced.
Where is part 03785 in the Amerex Parts Book?
Item 6 on printed page 18 (PDF page 20) of Parts Book 27277 Rev D.
Does the same tube fit the 300 lb wheeled models 491 and 493?
No. The Parts Book lists 06789 as the nitrogen tube assembly for those models on printed page 19.
Is the Amerex 03785 a genuine Amerex part?
Yes. Amerex's Parts Book notice states that Amerex replacement parts must be used to protect the UL listing and keep the warranty in effect.