LANG
1. Two basic types are available, namely flanged type and wafer type (center-line), fully-lined wafer Butterfly valve applies bisection two-piece valve body combination, with the integration of valve seat and body lining, when the valve acts, only all-plastic seat and plastic-lined disc contact the medium, so the product can resist the corrosion of any media except for molten alkali and fluorine, the stem and disc of the butterfly valve is integral and is coated a layer of FEP on its surface. The valve body is smooth contributing to small flow resistance, high CV value, high flow capacity and moderate torque, applies 4-tier sealing structure, externally equipped with temperature-resisting and anti-aging flexible-gasket seat made of SI rubber, ensuring zero leakage of the medium.
2. Flange-type and wafer half-lining butterfly valve extended from the above Model No., with unlined internal components, disc and stem, is made from corrosion-resisting stainless steel; while the valve body applies fully-lined process, namely, half-lining butterfly valve.
Structural features
1.The center-line butterfly valve provides double sealing function which whole disc and disc seat are concentric (center lined) within the 360° circle, the pressure and flow capacity can be freely adjusted.
2. The 4-tier elastic seal ensures completely no internal and external leakage;
A. The reasonable interference between special transition curve at the joint of spindle nose and disc circle and the valve seat;
B. The combination of elastic O-ring, steel-made gasket at shaft collar and flexible rubber gasket is provided for spindle nose end face;
C. The axis radial applies the combination of O-ring and metallic gasket;
D. The seat is embedded on the elastic valve groove.
3. Adjustable elastic bullet positioner is used and advantaged of exact positioning and simple structure.
Design specifications: as per GB/T 12224, HG/T 3704 standards.
Driving mode: manual operation, turbine drive, pneumatic drive and electric drive.
a. Model D371F46 half-lining type: both valve body and disc are fully lined, while disc and disc shaft are integral.
b. Model D371F4 fully-lining type: both valve body and disc are fully lined.
c. Model D371F46 fully-lining type: valve body is fully lined while disc is stainless steel ( unlined).
Executive standard
Designed and manufactured：GB/T 12224, HG/T 3704
Structural length：GB/T12221
Flange dimensions：HG/T20592 / ASME B16.5
Pressure test：GB/T13927
Symbol：GB/T 12220
Supply：JB/T 7928
