China Wafer Style Butterfly Valve Manufacturer & Manufacturers

A wafer butterfly valve features smooth, unthreaded alignment holes or centering ears designed to be clamped between pipe flanges using long continuous through-bolts. This makes it significantly lighter, faster to install, and more economical. However, it cannot be used for dead-end service because removing downstream piping releases bolt tension on the valve. A lug style valve has threaded tapped ears along its body perimeter, allowing each flange to be bolted independently so downstream lines can be dismantled while upstream pressure remains isolated.

Standard concentric wafer valves cannot be used for dead-end isolation without a companion blind flange bolted downstream. Clamping force from both upstream and downstream flanges is necessary to keep the resilient elastomeric seat compressed and leak-tight. For applications requiring regular line maintenance and end-of-line isolation, engineers should specify lug style or double flanged butterfly valves.

Total actuator sizing torque is the sum of seat seating/unseating friction torque, bearing friction torque, hydrodynamic dynamic torque caused by fluid velocity across the disc, and hydrostatic imbalance torque. When sizing electric or pneumatic actuators, manufacturers apply an engineering safety factor of at least 1.25 to 1.35 over the maximum calculated unseating torque at maximum differential pressure (ΔP), ensuring reliable opening even after prolonged stationary closure.

Elastomeric seat swelling typically stems from chemical incompatibility with the line media, such as using standard EPDM with trace hydrocarbons or lubricating oils, or using NBR with aggressive polar solvents, ketones, or high ozone concentrations. Chemical absorption causes the polymer matrix to expand, sharply increasing operating torque, causing premature seat tearing, and potentially locking the valve disc. Matching the elastomer to the fluid's chemical composition and temperature profile is critical.

Tianjin Zhongfa Valve's universal wafer bodies feature slotted centering holes designed to fit seamlessly between multiple drilling standards, including ASME B16.1 Class 125, ASME B16.5 Class 150, EN 1092-2 PN10/PN16, BS 4504, JIS B2238 10K, and AS 2129 Table E. This design simplifies inventory management for global distributors by allowing one valve body to serve multiple international pipeline standards.