Woods calls this a 3rd function valve, but look at the picture.
Excerpt:
This optional 3rd function valve kit is available for LF
loader models. This valve can supply oil for the operation
of loader mounted attachments such as a grapple,
multi-purpose bucket or bale clamp. The valve is
an electrically controlled diverter valve that directs oil
from the bucket circuit to an auxiliary function.
http://www.woodsequipment.com/uploadedfiles/products/manuals/man0659.pdf
Some people use the term True 3rd Function. Just what is the description for a True 3rd function valve?
Would you say that it has to have a solenoid valve and a subplate?
If a single solenoid and subplate is a 3rd function valve, what do you call three solenoid valves on a subplate. Would you call it a ganged 3rd function.
Can a manual valve be a 3rd function. If I install a manual valve after the loader, is it a 3rd function valve?
Some people are going to say, why everybody knows what it is, but guess what, they don't.
When I use the term, I am thinking a single solenoid valve on a subplate with an IN port, an OUT port and two work ports, and maybe a relief port, and all ports are high pressure about 3000 to 5000 psi rating, so there is no need to mentioned a PB port.
The 3rd function valve can be installed anywhere in the open center hyd system before the 3pt valve including the loader valve if the subplate has a relief valve installed. You also have to consider that when the solenoid is activated, all flow goes to the subplates work ports and what comes out of the T port is the expended cyl fluid..
If you have a hyd motor controlled by a 3rd f unction valve you are giving the hyd motor full pump flow and the downstream flow is now from the hyd motor.