Valve Handle Orientation in Cold Service

Probably so the valve can be repaired while in service......

This is just a thought (no real knowledge on the subject).

It might be due to condensation. I would imagine the pipe line and valve body are heavily insulated, the valve stem really can't be insulated as well, as it has to transmit the force from the handle/actuator to the internals of the valve. Therefore it's exposed to heat transfer, and condensation (depending on the humidity of the air surrounding the system).

I'm assuming when you say "vertical direction", you mean the valve stem is vertically down (not up - which is quite standard).

The condensation may cause problems with the lubrication in the valve or something. I doubt there is a chemical compatability issue with condensation.

Actually if the valve stem was vertical upwards, the condensation would drip down around the valve, eventually forming a giant block of ice. If the valve stem is vertical down, the condensation drips away from the valve.

Again, just guessing.

Hope this helps.

Anthony

What kind of valve?

This is from ENG-TIPS Forum:

Take a look at FAQ 774-566 its for Cryogenic valves but also relates to low temp valves such as you require.
The shaft can be as much as 45 degrees from vertical if the extension is long enough, try and comply with a known standard such as shell's then you cannot go wrong, these have been put together after a lot of research, although the extensions will be short it is really important never to get a valve packing frozen by providing insulation up the extension, the extension must be in open air unless in a cold country where trace should be used.
These questions appear to be asked almost every year, try a couple of searches in cryogenics and this forum for low temp /cryogenic standards