截止阀的启闭件是阀瓣，阀瓣沿阀座中心线做升降运动来实现阀门的开启和关闭。与闸阀不同，截止阀的流道并非直线贯通，介质在通过阀门时需要改变流动方向，因此流动阻力相对较大。然而，这种结构设计也带来了闸阀无法比拟的优势——密封性能更为可靠，且具备一定的流量调节功能。

The opening and closing component of a globe valve is the valve disc, which moves up and down along the centerline of the valve seat to achieve the opening and closing of the valve. Unlike gate valves, globe valves do not have a straight flow path, and the medium needs to change its flow direction when passing through the valve, resulting in relatively high flow resistance. However, this structural design also brings unparalleled advantages over gate valves - more reliable sealing performance and certain flow regulation functions.

良工截止阀在产品设计上注重密封的可靠性和使用寿命的延长。以J41H型法兰截止阀为例，其密封面硬度高、耐磨、耐高温、耐腐蚀，抗擦伤性能优异，使用寿命长。阀杆经过调质及表面氮化处理，具有良好的抗腐蚀性、抗擦伤性和耐磨性。这些材料和工艺上的精良处理，确保了截止阀在频繁启闭的工况下依然能够保持可靠的密封性能。

Lianggong globe valves pay attention to the reliability of sealing and the extension of service life in product design. Taking the J41H flange globe valve as an example, its sealing surface has high hardness, wear resistance, high temperature resistance, corrosion resistance, excellent scratch resistance, and long service life. The valve stem has undergone quenching and surface nitriding treatment, exhibiting excellent corrosion resistance, abrasion resistance, and wear resistance. The excellent treatment of these materials and processes ensures that the shut-off valve can maintain reliable sealing performance even under frequent opening and closing conditions.

核级截止阀代表了良工阀门技术的最高水准。良工阀门是国内第一批获得民用核承压设备设计制造许可证的企业，其核一级截止阀的技术参数令人瞩目。

The nuclear grade globe valve represents the highest level of Lianggong valve technology. Lianggong Valve is one of the first domestic enterprises to obtain a design and manufacturing license for civil nuclear pressure equipment, and its technical parameters for nuclear first level globe valves are remarkable.

以良工核一级气动截止阀为例：公称通径DN15，压力等级1650Lb，设计压力高达17.13MPa，设计温度343℃。工作介质为反应堆冷却剂、设备冷却水、含硼水。端部连接采用承插焊方式，抗震类别为IA，电气鉴定等级为K1，启闭时间仅需10至15秒。

Taking the first stage pneumatic globe valve of Lianggong Nuclear as an example: nominal diameter DN15, pressure rating 1650Lb, design pressure up to 17.13MPa, design temperature 343 ℃. The working medium includes reactor coolant, equipment cooling water, and boron containing water. The end connection adopts socket welding method, with seismic category of IA and electrical identification level of K1. The opening and closing time only takes 10 to 15 seconds.

在设计上，这款核一级截止阀攻克了多项技术难题。通过解决深孔堆焊的技术难题，阀体采用了轻巧的整体自由锻造结构，有效降低了阀门重量和安装高度，提升了抗震性能。阀体与阀盖的连接采用螺纹连接形式，由阀盖底平面压紧垫片、上平面与阀体完全啮合，外圈带唇边焊的多重密封结构——这种设计解决了传统垫片密封中阀体阀盖不能完全啮合、留有缝隙、一旦焊缝失效就容易泄漏的缺陷。从设计和结构上消除了密封泄漏的隐患，确保了核电站一回路系统的绝对安全。

In terms of design, this nuclear first stage globe valve has overcome multiple technical challenges. By solving the technical difficulties of deep hole welding, the valve body adopts a lightweight integral free forging structure, effectively reducing the weight and installation height of the valve and improving its seismic performance. The connection between the valve body and the valve cover adopts a threaded connection form, with the gasket pressed by the bottom plane of the valve cover, the upper plane fully engaged with the valve body, and a multiple sealing structure with lip welding on the outer ring. This design solves the defects of traditional gasket sealing, such as incomplete engagement of the valve body and valve cover, gaps, and easy leakage once the weld fails. The hidden danger of sealing leakage has been eliminated from the design and structure, ensuring the absolute safety of the primary circuit system of the nuclear power plant.