Jamming cryogenic service valves with bellow seal
Jamming cryogenic service valves with bellow seal
(OP)
Hi,
I am currently facing some problems with below sealed globe valves used in cryogenic service (down to -40°C).
After only two to three actuations, the spindle gets stuck to the plug in the area where the rotational is tranlated to a linear movement. We have around 14bar in the system and the dimension of the valve is DN80.
Is anybody aware of this kind of problem? I think for DN80 usually the connection between stem and plug should be made by hardened balls to prevent the contact surfaces from levigating. This is not the case for the valves in question (contact surfaces are directly touching)




I am currently facing some problems with below sealed globe valves used in cryogenic service (down to -40°C).
After only two to three actuations, the spindle gets stuck to the plug in the area where the rotational is tranlated to a linear movement. We have around 14bar in the system and the dimension of the valve is DN80.
Is anybody aware of this kind of problem? I think for DN80 usually the connection between stem and plug should be made by hardened balls to prevent the contact surfaces from levigating. This is not the case for the valves in question (contact surfaces are directly touching)









RE: Jamming cryogenic service valves with bellow seal
RE: Jamming cryogenic service valves with bellow seal
Even at fairly 'warm' cryogenic temperature as minus 40 deg C, one should use valves designed for low temp cryogenic purposes. 'Allowed for minus 40 deg C' will not ensure troublefree service. Is this a valve construction where the supplier really can show long-term references for trouble free cryogenic services?
RE: Jamming cryogenic service valves with bellow seal
RE: Jamming cryogenic service valves with bellow seal
Knowing the alloys for those three parts would be helpful.
My hunch is that the valve is not designed for this service.
It may be an issue of material compatibility when cold, or clearances, or something else.
The translation from rotation to lifting is usually done externally in low temp valves (rising stem).
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P.E. Metallurgy, Plymouth Tube