I'm new at these remote hydraulics. Can someone explain to me the difference and advantages of the single spool valve and the double spool valve?
Does different attached equipment require one or the other?

Think of the need for a spool for each function you wish to control. A single spool valve is a valve body containing one spool, which will operate one hydraulic circuit. A double spool valve is one valve body containig two spools and their associated ports, sufficient to control two separate functions. A snowplow with manual angle would require a single spool valve to lift & lower the moldboard. A snowplow with hydraulic angle would require a two spool valve, one to operate the lift cylinder and one to operate the angle cylinder(s). Each spool may be configured differently, for instance valved for single or double acting cylinders, with or without float position, and with or without detents. Hope this helps.

Thanks, RickB. I suspected what you confirmed. You made a good analogy. Appreciate your help.