Butterfly valves have become one of the most widely utilized valve types in industrial processes due to their compact design and efficient operation. As leading manufacturers of high-performance butterfly valves, we want to provide insight into the engineering that goes into these versatile valves. Understanding key design considerations is important for engineers and facility managers to selecting the right butterfly valve for each application.
One of the primary factors that goes into a high-quality butterfly valve is the disc sealing method. Conventional valves use an elastomer O-ring seated in a circular groove to create a seal when closed. While simple and inexpensive, this static seal can wear over time and may leak at high pressures. Our patented triple offset butterfly valve design solves this problem through a seating methodology called triple offset.
Instead of a static seal, triple offset valves utilize a dynamic seal that results in a tighter, more durable shut-off. The disc is offset from the axis of rotation, as is the stem connection to the disc. When closed, any imperfections in the seat or disc surface are acutely compressed, forming an effective metal-to-metal seal capable of handling stringent requirements. This self-adjusting sealing produces low levels of friction and wearto significantly extend valve life.
Valve body and disc materials are tailored for each application. For corrosive services, valves are available in corrosion-resistant alloys like stainless steel, Hastelloy, titanium, and tantalum. For higher temperature applications, options include nickel alloys. Disc and shaft friction is reduced through use of self-lubricating carbon fiber or nickel plating on shafts. Liner materials such as PTFE or polyurethane coatings provide chemical resistance. Materials are rigorously tested by our engineers to ensure suitability for decades of use in the field.
Automation-friendly actuators are available for remotely or automatically controlling flow. Air-to-open or -close quarter-turn pneumatic actuators and electric actuators with positioners provide precise regulation.
Additional key considerations we address are tight shut-off capabilities and reduced vulnerability to process variability. High performance butterfly valve optimized for high performance applications are dynamically tested to exceed international piping standards on fugitive emissions. TWT as leading valve manufacturers in China, provides redundant sealing for fugitive emission rates below 1g/hr—exceeding specifications for refinery, petrochemical and LNG applications.
Our valves are also engineered to withstand surging pressure spikes and pulsations that can damage conventional valves over time. Features like reinforced shafts, discs and seats minimize distortion and leakage to deliver years of reliable operation in fluctuating process conditions.