Fire resistance test
In July 2018, LLC MUFTY NSK tested the fire resistance of NSK couplings in an accredited laboratory.
At a flame temperature of 800ºC, two types of fire-resistant couplings were tested for 30 minutes: with anchor rings and slip couplings. The tests were successful, on the basis of confirmed documents from the Marine and River Registers.
Flame retardant couplings are couplings in a fireproof enclosure. In the event of a fire, the fireproof casing increases in volume - its thermal expansion (swelling) occurs with a sharp rise in temperature. An insulating layer is formed. This layer prevents the sleeve from heating up, which keeps the connection tight.
The fireproof casing is lightweight and lightweight. Due to this weight and dimensions of the coupling increase slightly.
Test in seawater
In June 2018, at Rybinsk Shipyard JSC, NSK couplings were tested for interaction with sea water.
The sleeve was immersed in seawater for 21 days, withstood the saline environment without changes in technical characteristics.
The metal grade was confirmed for use in shipbuilding, rubber also did not change the declared properties.