Fire Extinguisher Hose Length and Burst Pressure Requirements

What hose length and burst pressure should a 20kg trolley extinguisher have?

A 20kg trolley dry powder extinguisher normally uses a discharge hose of 400–600 mm with a minimum burst pressure of 5.5 MPa (about 55 bar), which is roughly three times the 1.5 MPa working pressure. Shorter hoses suit compact carts; longer hoses give the operator reach on rough ground. Confirm the hose test certificate before you fix the specification in your purchase order.

For a complete unit, see the 20kg Trolley Dry Powder Fire Extinguisher. If you need to compare hose and valve options for your market, request an FOB quotation with your target length and pressure rating.

How do hose length and burst pressure change with extinguisher size?

Hose requirements scale with cylinder volume and working pressure, not with cart size alone. A 6kg portable and a 20kg trolley may share a similar valve thread, but the trolley hose carries more powder and is handled differently, so buyers should specify both length and pressure separately for each SKU.

Values above are typical ranges for ABC dry powder units. Your notified body or national authority may require a higher burst ratio, so always cite the standard your importer must meet in the purchase order.

Which standard governs hose length and burst pressure?

For Vietnam, the reference is usually TCVN 7026 (portable extinguishers) and the relevant QCVN fire code, with EN 3-7 and ISO 7165 used as the technical basis for design and testing. Hose performance is commonly checked against the hose clauses of these standards or against ISO 6804-type requirements for rubber and plastic hoses.

Practical points to verify on the test report:

• Hose length measured from the valve outlet to the nozzle coupling, not from the cylinder body.
• Burst pressure tested on a sample from the same production batch, not a generic certificate from a different hose supplier.
• Working pressure test held for a defined period, with no leakage at the valve, ferrule or nozzle joint.
• Ageing and UV exposure results if the hose will be stored outdoors or on a cart in sunlight.

Is the hose UV-resistant and rated for full working pressure?

For outdoor and industrial use, specify a hose with UV-stabilised EPDM or rubber compound and a braided or textile reinforcement. A hose that passes burst pressure on a new sample can still fail after months of sun exposure if the compound is not stabilised.

Ask for:

• Compound type and reinforcement construction.
• UV or weathering test reference, if available.
• Continuous working pressure rating equal to or above the cylinder working pressure.
• Nozzle material and coupling thread, so spare nozzles remain interchangeable.

What are the most common hose specification mistakes?

• Specifying length only. A 500 mm hose with a low burst rating is not equivalent to a certified 500 mm hose.
• Accepting a generic hose certificate. The report should match the hose model and batch supplied.
• Ignoring the nozzle coupling. A mismatched thread makes the unit hard to service locally.
• Using a portable-size hose on a trolley. Flow restriction can reduce discharge performance and increase discharge time.
• Skipping UV testing for outdoor carts. Hoses stored in sunlight degrade faster than indoor units.
• Not listing the hose in the spare parts order. Importers often stock valves and gauges but forget hoses.

What should a buyer checklist for hose approval include?

1. Hose length stated in millimetres, measured from valve outlet to nozzle coupling.
2. Working pressure and minimum burst pressure stated in MPa or bar.
3. Burst test report from the same hose model and production batch.
4. UV or weathering statement for outdoor use.
5. Hose bore and reinforcement type recorded on the datasheet.
6. Nozzle material, thread and spare-part availability confirmed.
7. Hose included in the spare parts price list.
8. Container loading plan updated with hose and cart dimensions.

How does hose choice affect container loading and spare parts planning?

Hose length affects the packed carton size only slightly, but the trolley frame, wheels and nozzle assembly dominate the packed dimensions. Confirm the packed length, width, height and gross weight per unit before you calculate container quantity. A 20kg trolley unit is typically packed as one carton or a palletised unit, and the hose is coiled and secured to the frame.

For spare parts, order hoses, nozzles and valves in the same shipment as the extinguishers. This keeps thread types matched and reduces the risk of local service centres fitting incompatible parts. Record the hose part number on the cylinder label or in the service manual so future orders are unambiguous.

Decision point: which hose specification should you approve?

Approve a hose only when length, bore, working pressure, burst pressure and UV resistance are all stated in writing and supported by a batch-matched test report. If any item is missing, request a revised datasheet before placing the order. For Vietnam, check whether your local distributor or authority requires TCVN 7026 marking or additional testing, and include that requirement in the purchase order so the factory can prepare the correct documents.