Flame retardant couplings are couplings in a flame retardant enclosure.
Fire-resistant couplings NSK are manufactured in two different versions: with an anchor system and without an anchor system.
- In couplings with an anchor system, two special anchor rings are installed. When installing the coupling on pipes, as well as when the pressure increases, the anchor rings are embedded in the pipe. This serves as an additional fastening of the pipelines under axial load due to the pressure inside the pipes. Anchor rings, due to contact with the pipe, are an earthing conductor.
- Couplings without anchoring system are installed on fixed pipes.
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, the weight and dimensions of the coupling increase slightly.
Couplings NSK MFl-PP and NSK С-PP are used in case of additional requirements for special fire safety standards. The sleeve can withstand open fire for 30 minutes at a temperature of 800 ° C and retains its functional properties without causing any consequences