Precision machining procedure, controling the gap of stem and extened bonnet below 1mm, guarranting the smooth turning of stem, and  also reduced the possibility of freezing and lossing caused by cryogenic service.

Lip-seal(Elgiloy+PTFE)

The Lip-Seal not only have the flexible compensation function as spring, but also excellent sealing as PTFE.

Excellent sealing under cryogenic temp. fire safe design as the secondary sealing of graphite.

All the fastners are full threaded construction for cryogenic temp. it is effectively avoid fastners long deformation and sealing failed.

Stem: double sealing design, the primary sealing is lip seal, secondary sealing is packing, which can reduce the amount of packing usage.

By FEA design, best thickness of extended bonnet is calculated, it would guarrantee the best cooling effect.

The design of drip plate, it firstly enlarged the effective cooling area, avoid the freezing problem of stem and packing dynamic sealing area, resulted larger torque; secondly, it effectively stop the condensate water drop into body.

Double sealing on connection of body bonnet, the primary flexible. sealing is Lip-Seal, it's secondary sealing is gasket.

Imported PCTFE used as seat sealing, it has good flexible function under cryogenic condition, promising it's sealing. 

The ball hardened to make sure no scrathing under cryogenic temperture.