编者按
本世纪以来，国内离子膜烧碱项目快速发展。山东龙飞机电设备有限公司（益龙阀门）吸收先进设计和制造技术，以实际工况为基础进行国产化创新，而非简单替代。系列首篇关注循环水和蒸汽调节系统。
技术瓶颈
循环水杂质可能在流道死角积聚堵塞；高温高压蒸汽的侧向力可能使阀杆偏磨、泄漏，降低精度和寿命，增加停车风险。
结构优化
球芯形内腔
扩大流通截面，提高Cv值，以流线型腔体减少滞留和积聚，改善通过能力。
上导向阀杆
抵消侧向力，保持阀杆垂直及运行平稳，提高密封可靠性。
低摩擦填料
降低执行机构阻力，改善响应与调节精度，满足精细流量控制。
工业应用
原文列举烟台万华氯碱、山东海力、莘县华祥及昌邑海能，在循环水和蒸汽工序采用该系列，并报告维护周期延长、运行成本下降。
EGSC参数
DN25–DN300，PN10–PN100或ANSI Class 150/300/600；常温−29°C至230°C，高温350°C至560°C，低温−50°C至−17°C，夹套≥150°C，波纹管型−29°C至230°C；泄漏IV级。碳钢或不锈钢阀体，不锈钢或司太立堆焊阀芯阀座，线性或等百分比特性，法兰连接，可配薄膜执行器、定位器和过滤减压阀。
后续研发与预告
以解决现场问题为导向持续改进技术和质量。下一篇将讨论干氯气泄漏风险，以及C276与六角导向在材料和结构上的应用。
产品规格表
| 参数 | 原文规格 |
|---|
| 型号 | EGSC single-seat control valve |
| 标准 | GB/T 4213-2024, effective July 1, 2025; HG/T 20592/20615-2009; ANSI/ASME B16.5-2009 |
| 口径 | DN25–DN300 |
| 压力等级 | PN10–PN100; ANSI Class 150/300/600 |
| 常温配置 | −29°C to 230°C |
| 高温配置 | 350°C to 560°C |
| 低温配置 | −50°C to −17°C |
| 夹套配置 | ≥150°C |
| 波纹管密封配置 | −29°C to 230°C |
| 泄漏等级 | IV |
| 阀体 | 碳钢或不锈钢 |
| 阀芯与阀座 | Stainless steel; stainless steel with Stellite overlay |
| 流量特性 | 线性或等百分比 |
| 连接 | 法兰 |
| 附件 | Diaphragm actuator, electropneumatic/smart positioner, filter regulator |
Editor’s introduction
China’s membrane-cell caustic-soda projects have expanded rapidly this century. Shandong Longfei Electromechanical Equipment Co., Ltd., also known through its Yilong valve range, has developed domestic valve solutions by combining established design ideas with application-specific manufacturing improvements.
The aim is more than simple substitution: it is to improve the product for the actual operating conditions. This three-part series begins with circulating-water and steam-control systems.
1. Technical challenges
These systems are important to stable chlor-alkali operation, but conventional control valves can encounter:
- Retention and plugging: impurities in circulating water collect in poorly shaped passages or dead spaces, restricting flow.
- Uneven stem wear and leakage: lateral forces in high-temperature, high-pressure steam service can wear the stem unevenly, reduce accuracy, shorten life and increase shutdown risk.
2. Structural improvements
Rounded internal cavity
The new metal single-seat valve uses a rounded, streamlined internal cavity to increase the effective flow area and flow coefficient. Reducing retention zones helps the medium pass through without accumulating and causing blockages.
Top-guided stem
The upper guide counters lateral loads and maintains stem alignment. This improves movement stability and sealing reliability and helps extend service life.
Low-friction packing
Packing with a lower coefficient of friction reduces actuator resistance and improves response and regulating precision.
3. Reported industrial applications
The article lists Yantai Wanhua chlor-alkali operations, Shandong Haili, Shenxian Huaxiang and Changyi Haineng among its users. It reports use in key circulating-water and steam-control duties at several membrane-cell caustic-soda projects, with longer maintenance intervals and lower operating costs.
4. EGSC product specifications
| Parameter | Published specification |
|---|
| Model | EGSC single-seat control valve |
| Standards | GB/T 4213-2024, effective July 1, 2025; HG/T 20592/20615-2009; ANSI/ASME B16.5-2009 |
| Nominal size | DN25–DN300 |
| Pressure rating | PN10–PN100; ANSI Class 150/300/600 |
| Standard temperature configuration | −29°C to 230°C |
| High-temperature configuration | 350°C to 560°C |
| Low-temperature configuration | −50°C to −17°C |
| Jacketed configuration | ≥150°C |
| Bellows-sealed configuration | −29°C to 230°C |
| Leakage class | IV |
| Body | Carbon steel or stainless steel |
| Plug and seat | Stainless steel; stainless steel with Stellite overlay |
| Flow characteristic | Linear or equal percentage |
| Connection | Flanged |
| Accessories | Diaphragm actuator, electropneumatic/smart positioner, filter regulator |
5. Further development
Yilong views technical capability and product quality as the basis of competition. Continued development focuses on solving real operating problems and improving domestic valve technology.
Next in the series
After flow-path and wear issues, the next article considers dry chlorine and the consequences of leakage. It examines Hastelloy C276 and hexagonal guidance as part of the materials and structural approach to this demanding duty.
