活接低温截止阀

活接低温截止阀是一种专为低温工况（通常指 -40°C / -40°F 以下）设计的管道开关控制装置。其核心功能是在低温介质（如液氮、液氧、LNG、液态二氧化碳等）的输送系统中，稳定地接通或截断流体流动，并确保在极低温度下仍能保持很好的密封性能和操作灵活性。

活接低温截止阀主要特点：

低温设计： 阀体、阀盖等主要部件通常采用耐低温材料（如不锈钢CF8M/316SS、LCB等），并经过深冷处理，以防止材料在低温下发生冷脆性，保持机械强度。

活接结构： 阀门两端采用活接（由任）式连接。这意味着它可以通过螺纹接头和锁紧螺母（Union Nut）快速与管道连接或拆卸，便于安装、维护和更换，无需移动整个管段。

截止功能： 采用上升阀杆式设计，通过手轮旋转带动阀瓣（Disc）垂直升降，实现与阀座（Seat）的紧密贴合或分离，从而达到稳定的开启和关闭。关闭状态能确保极低的泄漏率。

长颈阀盖： 通常配有加长的阀盖（Extended Bonnet）或阀杆。其目的是使阀杆的填料密封函（Stem Packing）远离低温流体，保持其处于环境温度，防止填料冻结，确保阀门能够被轻松操作，并有效隔离冷量向外部传递。

活接低温截止阀密封性能： 阀瓣与阀座的密封面常采用硬质合金（如STL硬质合金）或聚合物（如PCTFE、PTFE）材料，以确保在低温下的密封稳定性和长寿命。

活接低温截止阀应用领域： 广泛应用于空分设备、液化天然气（LNG）装置、冷库、石油化工、工业气体储存与运输等低温领域。

活接低温截止阀产品名称：Union Type Cryogenic Globe Valve

The Union Type Cryogenic Globe Valve is a specialized flow control device designed for cryogenic service conditions (typically at below -40°C / -40°F). Its primary function is to reliably start stop the flow of cryogenic media (such as Liquid Nitrogen, Liquid Oxygen, LNG, Liquid CO₂, etc.) within piping systems. It is engineered to maintain exceptional sealing performance operational flexibility under extreme low temperatures.

Key Features:

Cryogenic Design: Key components like the valve body bonnet are manufactured cryogenic-grade materials (e.g., Stainless Steel CF8M/316SS, LCB) often undergo deep cryogenic treatment to prevent cold embrittlement ensure mechanical integrity.

Union Ends: The valve features union ends at both inlet outlet. This design allows for quick connection to disconnection the pipeline using the union nuts, facilitating easy installation, maintenance, replacement without moving the entire pipe section.

Shut-Off Function: It employs an rising-stem design. Rotating the handwheel moves the disc vertically to the seat, achieving reliable opening tight shut-off. It ensures very low leakage rates in the closed position.

Extended Bonnet: A characteristic extended bonnet ( stem) is incorporated. This design keeps the stem packing away the cryogenic fluid, maintaining it at near-ambient temperature. This prevents the packing freezing, ensures smooth operation, acts as a thermal barrier to minimize heat ingress.

Sealing Performance: The seating surfaces (disc seat) often utilize hardened alloys (e.g., STL) suitable polymers (e.g., PCTFE, PTFE) to guarantee reliable sealing long service life in cryogenic environments.

Applications: Widely used in air separation plants, LNG (liquefied natural gas) systems, cold storage facilities, petrochemical industries, industrial gas storage transportation.