The BVC Butterfly Valve is a highly developed design. A double offset disc design has been chosen which YLOK insists provide significant benefits in ANSI 150 and 300 rating over the triple offset design. Importantly they cost only a third to half that of the triple offset design. A key technical feature of the double offset design as is its lower operating torque when compared with triple offset styles. The BVC High Performance Fire-Safe Butterfly Valves have been independently tested by Pcell Research Ltd, whose conclusion after the valves passed all tests was that they were “particularly impressive.” Butterfly valves were frequently viewed as only suitable for moderately severe applications and fire-safe was often something of a pipe dream. Technology has moved dramatically on with the BVC design not only being fire-safe but bi-directionally so. Seal design has been developed to a very high degree offering metal/PTFE and metal-to-metal seating. The design also incorporates many features that make them valves of extremely high quality. An over-travel stop control is integral in the body/disc design, as is the use of a special key to secure the disc to the shaft. This gives greater strength to the shaft/disc assembly and allows for easy maintenance of the valve. The disc design also provides a clean profile for minimum flow turbulence and obstruction.