Cast iron gate valve

Cast iron gate valve is a block valve with a gate as the opening and closing element. The direction of movement of the gate is perpendicular to the fluid, and it has the characteristics of low flow resistance and allowing the medium to flow in both directions. Its structure has a large height and a long opening and closing time, and is divided into two types: wedge-shaped (including single gate, double gate, and elastic gate) and parallel gate plate (including single gate, double gate). According to the structure of the valve stem, it can be divided into rising stem gate valves (with exposed stem threads for easy lubrication) and hidden stem gate valves (with internal threads, the stem only rotates). The valve body material includes gray cast iron, carbon steel, stainless steel, etc., connected by flanges, with a nominal diameter covering DN40-DN1200, suitable for pipelines in industries such as water, steam, oil, petrochemicals, pharmaceuticals, and power [2] [4-5].
The sealing surface of the valve adopts a wedge-shaped design, relying on self sealing or external force to force closure, but maintenance is inconvenient. The double gate model requires vertical installation, while the concealed rod model is suitable for confined spaces [3]. The improved design includes automatic adjustment of the drive motor, threaded rod transmission structure, and magnetic block sealing device, and optimizes the gate arc structure to reduce fluid resistance [6-7]. Some models have a working pressure of ≤ 1.0MPa and comply with standards such as ANSI and JIS-10K [4-5].