Gost & Rotta Couplings

A Gost coupling (also written GOST coupling or Гост муфта in Russian) is a symmetrical two-claw fire hose coupling specified under the Russian national standard GOST 28352-89. Both halves of the coupling are identical — similar in principle to the European Storz coupling but with a different lug geometry — allowing rapid connection without orientation checking.

Gost couplings are the universal fire hose coupling standard across Russia, Ukraine, Belarus, Kazakhstan, Azerbaijan and all former Soviet republics. They are found on every Russian fire truck, fire station hose rack, industrial fire hose reel and municipal fire hydrant cabinet in the CIS. Gost couplings are also common in Eastern European countries that retain Soviet-era fire equipment inventories, and in export fire tenders supplied to parts of Africa and the Middle East.

CA-FIRE manufactures Gost couplings in sizes DN50 to DN150 in aluminium casting and brass casting. Full details of the complete coupling range are available on our firefighting couplings overview page.

Gost couplings and Rotta couplings are both Russian-standard fire hose fittings used in CIS fire systems, but they have different designs and applications:

Gost coupling: symmetrical two-claw hermaphrodite design (both halves identical). Used to connect two lengths of fire hose together, or to connect a hose to a pump or hydrant fitting. Quick to connect and disconnect — one half rotates approximately 60° to engage or disengage the claws. Sizes DN50 to DN150. Most common for general fire hose delivery and suction use.

Rotta coupling: three-lug interlocking design with a body that receives the lugs of the opposing fitting. Used primarily for fixed connections at pump outlets, hydrant inlets and fire hose reel connections where a more positive locking action is required. More resistant to vibration-induced disconnection than the Gost two-claw system. Available in DN50 and DN70 only.

In practice, Gost and Rotta couplings are not interchangeable — they use different connection geometries. A Gost coupling will not connect to a Rotta coupling without an adaptor.

Yes — provided both couplings conform to GOST 28352-89 and are the same DN size, they will be fully interchangeable regardless of manufacturer. The GOST standard defines the body diameter (A dimension), claw geometry, gasket seat and rotation angle precisely enough that compliant couplings from any manufacturer will connect and seal correctly.

CA-FIRE Gost couplings are dimensionally verified against the GOST 28352-89 specification for every production batch. A CA-FIRE DN70 aluminium Gost coupling will connect with any DN70 GOST-compliant coupling from any other manufacturer. This is essential for fire service interoperability — a fire truck arriving with CA-FIRE Gost-coupled hose must be able to connect to the existing municipal hydrant system and other appliances on scene.

Note: some markets produce "Gost-style" couplings that nominally resemble the Gost design but are not dimensioned to GOST 28352-89. Always confirm compliance with the standard when purchasing couplings for fire service use.

CA-FIRE Gost couplings are available in DN50, DN70, DN80, DN100, DN125 and DN150. Within each DN size, multiple hose tail bore sizes are available to match different hose internal diameters.

DN50 (body Ø 78 mm) — the most common size for standard fire attack hose (51 mm / 52 mm bore). Used on the majority of Russian fire truck attack lines and in fire hose cabinet installations.
DN70 (body Ø 95 mm) — used on larger-bore delivery hose (65 mm / 75 mm). Common for supply lines from hydrant to pump.
DN80 (body Ø 107 mm) — for large-bore delivery and light suction hose (75 mm bore).
DN100 (body Ø 140 mm) — for heavy suction hose on fire pump inlets.
DN125 (body Ø 166 mm) — large suction hose, pump inlet connections.
DN150 (body Ø 186 mm) — largest size, for very large diameter suction hose.

For most fire hose supply projects to Russian and CIS markets, DN50 and DN70 account for the majority of volume. DN80 and larger sizes are typically used only on suction hose and pump connections.

Gost to Storz: Gost and Storz couplings use completely different connection geometries and are not directly interchangeable. To connect a Gost-coupled hose to a Storz-coupled hose or fitting, a Gost × Storz adaptor is required — this is a double-ended fitting with a Gost coupling on one end and a Storz coupling on the other. CA-FIRE can manufacture custom mixed-standard adaptors for project requirements — contact our sales team.

Gost to BSP thread: CA-FIRE manufactures Gost female thread (GOF) and Gost male thread (GOM) adaptors that allow a Gost coupling to connect to a BSP-threaded fitting such as a pump outlet, hydrant valve, nozzle or fire hose reel connection. These are available in G2", G2-1/2", G3" and G4" BSP thread sizes in aluminium and brass casting. See the Gost Thread Adaptors tab in the product table above for full codes.

A Gost coupling reductor (also called a Gost reducer) is a double-ended Gost fitting that connects two Gost couplings of different DN sizes to each other. They are used when a larger-bore suction or supply hose needs to be connected to a smaller-bore attack hose or pump outlet. Available from CA-FIRE in the following size combinations:

GO70-GO50: connects DN70 to DN50 (e.g. supply hose to attack hose)
GO80-GO50: connects DN80 to DN50
GO80-GO70: connects DN80 to DN70
GO125-GO70: connects DN125 to DN70 (large suction to supply line)
GO125-GO80: connects DN125 to DN80

All Gost reductors are manufactured in aluminium casting. For related products, see the Coupling Accessories page.

Aluminium Gost couplings are the standard choice for most fire service applications. Aluminium casting is lighter than brass — a DN70 aluminium Gost hose coupling weighs approximately 0.8–1.0 kg less than the brass equivalent — making it easier to handle in operational conditions. Aluminium couplings are suitable for use with fresh water, treated water and standard foam concentrates.

Brass Gost couplings are specified for installations where superior corrosion resistance is required — seawater exposure, coastal installations, chemical plant fire hose systems and potable water networks. Brass casting provides significantly better corrosion resistance than aluminium in saline and chlorinated environments. Brass couplings are heavier but have longer service life in aggressive environments.

Both aluminium and brass Gost couplings are manufactured to the same GOST 28352-89 dimensional specification and are dimensionally interchangeable — an aluminium Gost coupling will connect to a brass Gost coupling of the same DN size without any fitting issues. This allows mixed material use within the same hose network, for example aluminium for field hose and brass for permanently installed hydrant cabinet connections.

To receive an accurate quotation for Gost or Rotta couplings, please provide the following when contacting CA-FIRE:

1. Coupling type — Gost hose tail (GOT), Gost female thread (GOF), Gost male thread (GOM), Gost blind cap (GOC), Gost reductor, Rotta hose tail (ROT), Rotta female thread (ROF), Rotta male thread (ROM) or Rotta blind cap (ROC).
2. DN size — DN50, DN70, DN80, DN100, DN125 or DN150 (Gost); DN50 or DN70 (Rotta).
3. Hose tail bore — internal diameter of the hose in mm (e.g. 52 mm, 64 mm, 75 mm).
4. Thread specification — BSP thread size if ordering GOF/GOM/ROF/ROM adaptors (G2", G2-1/2", G3", G4").
5. Material — aluminium casting (AL) or brass casting (BR).
6. Quantity — pieces per SKU.
7. Special requirements — custom packaging, private-label marking, test certificates.

Contact CA-FIRE at sales@ca-fire.com, via WhatsApp, or via the contact page. We respond within 24 hours.