Insights · Fire-Fighting
Wang Fuk Court Fire: Why Forged Fire Hose Couplings Matter in Fire Rescue
· Updated ·3 min read
On 26 November 2025, a fire broke out at Wang Fuk Court, a housing estate in Tai Po, Hong Kong. It was raised to a No. 5 alarm, the city’s first in 17 years, spread to seven of the estate’s eight blocks and took about 43 hours to put out. The authorities put the final death toll at 168, among them firefighter Ho Wai-ho.
Our thoughts are with the families of those who died and with the firefighters who worked through the night. The causes of the fire are a matter for the official investigation, and this article does not speculate about them. It looks at one piece of equipment that every fire-ground relies on: the hose coupling.
What a hose coupling has to survive
A large fire puts enormous demands on equipment. By the day after the Wang Fuk Court fire, the Fire Services Department had sent more than 200 fire appliances and about 1,200 fire and ambulance personnel to the scene. Every line of hose they laid was joined by couplings: hose to hose, hose to hydrant, hose to pump and hose to nozzle.
A coupling has one job: hold a leak-free connection under pump pressure. It has to do that after being dropped on concrete, dragged across the ground, connected and disconnected many times, and stored outdoors for years. A coupling that leaks or cracks costs water pressure at the nozzle and time to replace it.
Forged vs. cast couplings
Most aluminum hose couplings are either cast or forged.
- Cast couplings are made by pouring molten metal into a mold. Casting is cheap for complex shapes, but gas and shrinkage porosity can form inside the part as it cools. Porosity can make a coupling leak in a pressure test, and castings are generally less tough, so they are more likely to crack when knocked.
- Forged couplings are pressed from a solid billet of hot metal in closed dies. Forging closes internal porosity and makes the grain flow follow the shape of the part, which gives a dense, tough coupling that resists impact and holds pressure.
| Cast coupling | Forged coupling | |
|---|---|---|
| Internal structure | Risk of gas and shrinkage porosity | Dense, porosity closed by forging |
| Grain flow | Random | Follows the part’s shape |
| Impact resistance | Lower toughness, may crack | Higher toughness |
| Pressure tightness | Porosity can cause leaks | Leak-tight when machined and sealed correctly |
How Aviaforge makes forged Storz couplings
Aviaforge forges Storz couplings, the symmetrical quarter-turn couplings used by fire services across Europe, from EN AW-6082 aluminum alloy:
- Forging: hot die forging
- Heat treatment: T6
- Machining: CNC finish machining of the claws, seal seat and threads
- Surface: hard anodizing
- Seal: NBR profiled seal
- Sizes: Storz 25 (D) to Storz 150, to the DIN 14301–14323 series, with hose shank, female or male thread, and as blank caps
- Inspection: hydrostatic pressure testing, X-ray inspection, fluorescent penetrant testing and hardness checks
A real example
A German fire-fighting equipment manufacturer came to Aviaforge because its cast couplings leaked in hydrostatic tests, cracked on impact in the field, and arrived with unreliable lead times. After switching to forged EN AW-6082 couplings, the client reported:
- couplings about 18% lighter than the cast parts they replaced
- a batch pass rate of 97% or more
- a standard lead time of 4–6 weeks
Read the full story: Forged Aluminum Storz Couplings for a German Fire-Fighting Equipment Manufacturer.
Frequently asked questions
Are forged fire hose couplings better than cast ones? For strength, toughness and pressure tightness, yes. Forging closes the internal porosity that can make cast couplings leak and aligns the grain flow with the part, so forged couplings resist impact better.
What material are Aviaforge Storz couplings made of? EN AW-6082 aluminum alloy, heat treated to T6 and hard anodized, with an NBR seal.
Which Storz sizes does Aviaforge make? Storz 25 (D) to Storz 150, to the DIN 14301–14323 series: couplings with hose shank, threaded couplings and blank caps. See Storz couplings and Storz couplings with shank.
Need forged couplings to your drawing or standard? Send us an inquiry.
