Triple-offset valves have become a market leader for high-quality isolation on a wide range of process applications. They offer tight shut off in a comparatively low cost body design.
Following an engineering design review of the Batley triple-offset butterfly valve BV 28000, the product has been re-developed to incorporate differentiating new features that improve both product performance and maintainability.
The most significant feature added to the valve is that the seat is no longer machined as part of the body profile, but is incorporated into a separate seat-ring which is bolted into the valve body as a cartridge. The seat ring is now a fully serviceable component which in turn means that the valve can be serviced without having to replace the complete body assembly.
On many triple-offset valve designs, actuator sizing often results in relatively large actuators, due to the out of balance forces acting on the disc. In the Weir design the stem is designed with a robust shaft to enable the valve to handle a wide range of actuator torques. Overall the Weir design will operate with significantly less torque than similar competitor’s valves.
By introducing these new features, Weir has not compromised on the more fundamental requirements of a triple-offset butterfly valve, namely the valve has a high integrity seat which improves when more process pressure is added to the line. The valve can be used across a wide range of temperatures and inherently, due to the design, the valve is not susceptible to thermal binding regardless of temperature fluctuations. This is important when considering how power plants are operated in today’s markets where many of the valves are thermally cycled throughout the day.
