BUTTERFLY VALVES METAL TO METAL SEAL :: FEATURES MMVI is glad to show you its main product range: triple eccentric valves metal to metal seal quarter-turn range METAL POWER. The METAL POWER range grants a perfect seal and for this reason it is suitable to work into different industrial plants (chemical, petrochemical, petroleum refineries, off-shore platforms, nuclear plants, power plants, remote heating, steelworks, cryogenic plants, sugar and paper mills) at any kind of temperatures, pressures and fluids (even corrosive). This range of valves grants a perfect "zero" leakage thanks to: 1) the couple closure that permits a continuous performance even in case of bi-directional fluid; 2) the seal ring that improves the tightness through the contact with the seat. The shaft positioned out of the axis with reference to the seat centre line and to the valve axis creates the double eccentricity. The triple eccentricity is determined by the elliptical seat obtained as a cone section whose axis is tilted with reference to the valve axis. The triple eccentric movement avoids any friction during the opening and closure phase of the valve and it allows an equal pressure around the whole seat. The powers created by the torsion during the closure became equal around the whole circumference. The seal ring flexes assuming the seat shape. The compression powers equally distributed around the perimeter create a tight bi-directional closure. The seal ring elasticity allows the body and the valve disc to contract and expand without seizure risk due to temperature fluctuations. The valve manufacturing following the standards API 609, ISO 5752, ASME B16.10 allow the same to substitute (through a simple installation) other kind of valves previously included into the industrial plants. The compactness and lightness represent other advantages of the butterfly valve, reducing the weight and dimensions in comparison with other kind of valves on the market. As the METAL POWER range is completely manufactured in metal it is intrinsically fire safe. CONSTRUCTIVE VERSIONS The METAL POWER range can be manufactured with the following connections: - FLANGED with flanges at the two ends. - LUG with threaded holes in the body. This connection is more compact and with lower face to face   dimensions. - WAFER with four holes for the valve centering. Lightness is its main advantage. - BUTTWELDING with two welding bevels made in accordance with standard and with the customer   requests. The welding bevels are equipped with centering ring for the positioning and line welding. Upon simple request the customer we can realise special connections.