The FFNV(w) butterfly valve with vulcanized seat, is used when a flanged valve is required to be mounted with bolts each side of the valve.
It is advised for these services, since it does not require almost maintenance, because of vulcanized ring on the body. This design is recommended for “end of line” service too.
FFNV(w) in the range of DN 40 to 1000 series 14 according to the EN 558-1
The main features are: Strong design, long life time, vulcanized seat, several options for material components, high thickness coating, exchangeable components with other Sigeval designs.
The internal surface of the valve in contact to the fluid, is covered with rubber so the disc and body is fully tight. Also, rubber offers advantage of high resistance to corrosion if we compare it to just internal coated bodies.
Main markets are: water distribution, naval industry, gas and cooling systems and also cheaper alternative, in some cases, to double eccentric valve.