Symmetrical couplings
Symmetrical couplings – general information
Symmetrical couplings feature a symmetrical design of locking heads (both parts of the coupling are exactly the same – no distinction between a coupler and an adapter) Therefore they can be quickly and easily connected – by pressing both parts against each other and turning. It is important to connect the halves with the lugs spaced at exactly the same distance. High, unrestricted flow rate, resistance to contamination and external damage are the key features of the symmetrical couplings.
The symmetrical couplings are intended for the applications transferring, loading and unloading water or other liquid substances as well as dry loose materials. Widely used in fire fighting, irrigation systems, drainage systems, chemical and food industry, marine industry, construction industry and agriculture, etc.
There are many standards of the symmetrical couplings:
NOR (Norway) symmetrical couplings
NOR coupling (also called Norlas) is a symmetrical coupling that comes from Norway. The coupling has two lugs, swivel locking ring secured with a screw. Available in three sizes with different lug spacing: Lock 1 (Las 1) – lug spacing 83 mm, Lock 2 (Las 2) – lug spacing 66 mm, Lock 3 (Las 3) – lug spacing 50 mm. Working pressure 10 bar. They must not be used for vacuum. In Norway they are widely used as fire fighting couplings and in water drawing systems. Globally, they are used in the shipbuilding industry and offshore applications (Lock 2 in particular). We offer NOR couplings with a hose tail, couplings with BSP female and male thread, blank caps. NOR couplings are made of bronze as a standard. The bronze construction ensures resistance to seawater and harsh weather conditions. NBR seal.
ROTTA (Russia) symmetrical couplings
ROTTA (ROTH) symmetrical couplings according to Russian coupling system standard. They feature simple, one-piece construction with 3 lugs. Available in two sizes, DN50 and DN70, with different lug spacing: Bronze for the body and NBR for the seal are used as standard materials. Resistant to corrosion and harsh weather conditions. Most of all, they are used in water delivery systems and fire fighting systems on ships. Working pressure 10 bar.
Our product range includes ROTTA couplings with a hose tail, ROTTA couplings with a male or female thread, blank caps and seals.
GOST no. 28352-89, 2217-66 (Russia) symmetrical couplings
Symmetrical couplings designed in accordance with Russian GOST 28352-89 standard (former standard GOST 2217-66). Widely used in fire fighting equipment in former Soviet Union countries, in Cuba and Vietnam. Used on ships and oil rigs as well. The couplings feature two-piece construction with a swivel head and two lugs. They are used for delivery and suction-delivery applications. The most popular sizes: DN50 – lug spacing 78 mm, DN70 – lug spacing 95 mm and DN 80 – lug spacing 107 mm. They are either made of bronze (marine application) or aluminium (standard fire fighting application). NBR seal. Working pressure 10 bar.
Our product range includes GOST couplings with a hose tail, GOST couplings with a male or female thread, blank caps and seals.
SMS (Sweden) symmetrical couplings
Symmetrical couplings according to SMS Swedish standard. Widely used for water delivery applications in fire extinguishing systems and on ships. There are two coupling sizes: DN32 with lug spacing 41 mm shaped as typical claw coupling and DN63 with lug spacing 76 mm and a single wide lug. DN 63 hose fitting with a swivel head is additionally equipped with a locking button. Made of seawater resistant bronze. NBR seal. Working pressure 10 bar.
Our product range includes SMS couplings with a hose tail, SMS couplings with a male or female thread, blank caps and seals.