I ran into a question today concerning a symbol located in the casting of a globe valve. In fact it is on every globe valve we are installing.

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I hope the symbol above makes sense to someone out there. We have been racking our brains all day searching catalogs and the net to no avail.

Any help would be appreciated!

It is showing the flow through the seating surface (the horizontal line).  Normally you'll install a globe valve with flow up through the seat (i.e., from right to left) to keep shut-in pressure off the packing, but this is not required by the manufacturer and is not a universal rule.  

Manufacturer's usually call a globe valve a bi-directional valve since the throttling characteristics are the same in either direction.  In steam plants we were really careful to ensure the flow was up, but in Oil & Gas it is rare to find someone who knows what the symbol means.

On the valves I'm familiar with, it will show you the orientation of the valve after it's in-line. If the flow is right to left, in your diagram, then it would enter the valve, come up under the disc, and exit. This is the traditional orientation, and allows you to close the valve, and repack the stem without depressurizing or draining the upstream piping run. On other applications, it is sometimes desirable to have the flow acting on top of the disc, and tend to drive it to the closed position, should it come off the stem. This orientation won't allow simply closing the valve, to repacking it, though.

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