1.USE用途

Cryogenic ball valves are applicable to pipelines of Class 150LB‑Class 900LB, PN16‑PN160, JIS10K and JIS20K ratings. They serve to cut‑off or open the medium inside pipelines. By adopting different material combinations, the valves are adaptable to media at various temperatures, with a minimum operating temperature down to ‑196°C. Available actuator options include manual operation, worm‑gear drive, pneumatic actuation and electric actuation. The cryogenic ball valves are normally furnished with flanged connections; welded‑end connection is also available as an alternative.

低温球阀适用于 I50LB 900LB、PNI6一 PN160、JIS10K、JIS20K 的各种管道。用于切断或接通管道中的介质。使用不同的材料，可适用于不同温度的介质，最低工作温度为 – 196°C。低温球阀的驱动方式有手动、蜗轮蜗杆传动、气动或电动。低温球阀一般采用法兰连接，也可采用焊接连接。

2.Characteristics of structure design and manufacturing结构设与制特点

Cryogenic ball valves are used in low-temperature working conditions, especially in some dangerous media working conditions such as lique fied natural gas. Company has accumulated rich experience in the design, manufacturing and testing of low-temperature ball valves.
低温球阀用于低温工况，特别是液化天然气等危险介质工况。公司在低温球阀的设计、制造、检测等方面积累了丰富的经验。

3.Use foaterials 使用材料

Common‑grade steel tends to produce low‑temperature brittleness under cryogenic conditions. Consequently, selecting proper body material in accordance with the minimum operating temperature of cryogenic ball valves is critical for design and manufacturing. The minimum applicable temperature for each valve‑body material is shown in the table below. Cryogenic‑grade materials shall undergo low‑temperature impact tests in compliance with standard requirements to guarantee their serviceability under cold‑temperature environments. Packing, gaskets, bolts and nuts shall also be made from materials suitable for cryogenic service.

一般的钢在低温下会表现出低温脆性。因此，根据低温球阀的最低工作温度选择合适的阀体材料是设计制造的关键。阀体材料的最低工作温度见下表。低温材料需要按照标准要求进行低温冲击试验，以保证材料在低温下的适用性。填料、垫圈、螺栓和螺母也需要由适合低温条件的材料制成。

4. Minimum Temperature of Body Materials 阀体材料最低工作温度

5.Characteristics of Structural Design and Manufacture 结构设计与制造特点

As required by standards, ball valves for service below ‑40℃ adopt an extended‑neck design to improve cryogenic resistance and ensure reliable packing sealing for the stem. The neck length can be customized per contract requirements. Low‑temperature tests are available to verify operating torque and sealing performance under cryogenic conditions. All valve components are subjected to cryogenic treatment so as to stabilize their shape and dimensions at low temperatures.
The valves are normally designed in compliance with relevant standards. Custom production is available according to contractual requirements if the client has special demands.
When the valve is closed, trapped medium inside the valve cavity vaporizes, which causes abnormal pressure build‑up inside the cavity. This will result in faults, even valve body rupture under severe conditions.

根据标准要求，温度低于‑40℃的球阀采用长颈结构设计，提升耐低温性能，确保阀杆填料密封可靠。颈部长度可按合同要求定制；产品可开展低温试验，检测阀门在低温工况下的操作扭矩和密封性能。阀门零部件经过深冷处理，保障零件在低温环境下尺寸与形态稳定。产品默认依照标准设计；如果客户提出特殊技术要求，则按照合同约定制造。当阀门处于关闭状态，介质滞留在阀腔内部，受环境影响介质发生汽化，会导致阀腔内压力异常升高，继而引发故障，严重时甚至造成阀体破裂。

6.Main dimensions and weight 主要尺寸和重量

The primary external connecting dimensions of cryogenic ball valves refer to those of side‑mounted floating ball valves and trunnion‑mounted ball valves. The overall valve height is based on the extended‑neck length, so separate dimensional standards are not listed.

低温球阀的主要外部连接尺寸参照侧装浮动球阀和固定球阀。阀门高度尺寸以长颈长度为基准，因此不再列出尺寸标准。