Gland Extension Length of Cryogenic Valve
For cryogenic valve, which shall be supplied with extended bonnets/glands . the length of the extension will be sufficient to maintain the stem packing at a temperature high enough to permit operation within the normal temperature range of the packing material. The general packing material is graphite, the normal temperature of packing should be 8 degree C and higher.
For cold box applications, valves shall be wiwth addition the minimum gland extension length as shown in below table.
For application other than cold box applications the minimum gland extension shall be 250mm .
If customer have special requirement about gland extension, shall provide comply with customer’s requirement.
Zhejiang Zhengfeng Valve.