Check valve

without锈钢法兰底阀是专为泵吸入端设计的防倒流设备，其作用是保证液体在吸入管内单向流动，使泵能够正常工作。 当泵短时间间歇停止工作时，液体不能返回水源箱，以保证吸水管内充满液体，以利于泵的启动。符合日本工业标准JIS B 2031（铸铁制阀门）及JIS B 2220（法兰标准），采用全不锈钢材质制造，适用于水处理、化工、食品等行业中腐蚀性介质的垂直管道安装。其核心功能在于防止停泵时介质回流，确保泵腔充满液体，减少空转风险。

Its structure and function are similar to that of a check valve, except that a filter screen is installed at the inlet to block impurities and protect the safety pipeline of the inlet. The 10K flange bottom valve is an energy-saving valve. Generally installed at the bottom of the underwater suction pipe of the water pump. It restricts the liquid in the pump pipeline from returning to the water source, playing a role of only entering without entering. There are many inlet products and reinforcement ribs on the valve cover. Not easy to block, mainly used for the function and support of pumping pipelines and waterways.

The following is an explanation from the dimensions of structure, materials, and performance:

‌1. 结构设计与密封特性‌

• ‌法兰连接与流道优化‌：
  阀体采用JIS 10K法兰（RF突面或RJ环连接面），法兰孔距及厚度严格匹配JIS B 2220标准（如DN50法兰厚度22mm，螺栓孔4×φ19mm）。流道设计为全通径结构，内壁经镜面抛光（粗糙度Ra≤0.8μm），减少介质流动阻力及残留。

• ‌双密封防泄漏系统‌：
  主密封面为阀瓣与阀座金属硬密封（SUS304堆焊硬质合金层，厚度≥1.0mm），副密封采用氟橡胶（FKM）或PTFE嵌入式垫片，耐受-20℃~150℃温度范围。阀瓣导向杆配置自润滑衬套，避免卡阻并降低启闭摩擦。

• ‌防堵塞底网结构‌：
  底部配置可拆卸式过滤网（孔径≤3mm，材质SUS316L），拦截管道杂质（颗粒物≤2mm），网篮与阀体采用卡扣连接，支持快速清理维护。

‌2. 不锈钢材质适配‌

• ‌主体材料‌：
  阀体、阀盖及内部组件均采用SUS304或SUS316奥氏体不锈钢，通过固溶处理提升耐晶间腐蚀能力，氯离子耐受浓度分别达200ppm（304）与1000ppm（316）。

• ‌特殊工况强化‌：

  • ‌酸性介质‌Upgraded sealing surface to Hastelloy C276 overlay, resistant to corrosive liquids with pH 2-10;
  • ‌高温场景‌The valve stem material has been replaced with SUS630 precipitation hardened stainless steel, and the applicable temperature has been extended to -196 ℃~300 ℃.

‌3. 性能参数与安装适配‌

• ‌压力-温度容限‌：
  公称压力1.0MPa（JIS 10K），常温下允许工作压力1.0MPa，100℃时降至0.7MPa。壳体强度试验压力1.5MPa，密封试验压力1.1MPa，泄漏率≤0.1mL/min（依据JIS B 2003）。

• ‌安装与流态控制‌：
  专为垂直管道设计（介质自下而上流动），阀瓣开启高度≥25%通径，确保低流速（≥0.2m/s）可靠动作。底部法兰预留排气孔（可选配堵头），便于系统排空操作。

‌4. 制造工艺与质量控制‌

• ‌精密成型工艺‌：
  阀体采用失蜡精密铸造，内部流道经五轴数控加工，尺寸公差控制±0.1mm；密封面通过磨削与抛光复合工艺，平面度≤0.03mm/m。

‌5. 典型应用场景‌

• ‌化工流程泵入口‌Transporting corrosive media containing weak acids and bases (such as dilute sulfuric acid, NaOH solution);
• ‌海水淡化系统‌Paired with duplex stainless steel material, resistant to chloride ion corrosion;
• ‌食品加工设备‌Meet the sanitary requirements of SUS316L material (surface electrolytic polishing, Ra ≤ 0.4 μ m).

‌技术总结‌The valve achieves reliable one-way cutoff and impurity interception function in the pump front protection scenario through stainless steel material corrosion resistance, double sealing structure, and modular filtration design. Its compact structure and convenient maintenance are particularly suitable for industrial systems with complex media and limited space. The selection should be comprehensively evaluated based on the corrosiveness of the media, temperature range, and installation direction.