Metal seated butterfly valves
Triple eccentric high-performance butterfly valves are equipped with a metal or metal/graphite seal.
In a triple eccentric butterfly valve, the flap rotates eccentrically, as the name suggests. Through this, a higher surface pressure is achieved between the flap and the seal, as well as a quick drop in surface pressure and friction when the valve is opened. In simple words, triple eccentricity allows higher tightness and lower opening torque.
The first degree of eccentricity derives from the fact that the shaft is behind the flap. The second degree of eccentricity is achieved by placing the shaft to the side with respect of the flap centre line. The third degree of eccentricity is implemented by machining the flap or body sealing surface in an eccentric manner.
Installation options include a model to be installed between flanges, a flanged model and a welded model.
Several application alternatives
Metal or metal/graphite-sealed triple eccentric butterfly valves are suitable for use with demanding media and at high temperatures.
A triple eccentric butterfly valve is not barely an on/off type valve but, as a custom-manufactured valve, it can also be used for control applications.
For use with fuels, Fire Safe valves are available, which are fire safety tested in accordance with the ISO 10497 standard or 6th edition of the API 607 standard, as well as ATEX-classified.
For stem seals, certification as per ISO 15848-1 or TA-Luft is available.
Typical applications of a triple eccentric butterfly valve include oil and gas production and processing, petrochemical industry, chemical industry, power plants, district heating, solar thermal power plants, pulp and paper industry, steel industry, and sugar industry.
The ARI Zetrix and RT valves in our range can be equipped with pneumatic or electric actuators.