SD8 Series Walvoil SDS150 RE/RK POWER BEYOND/CLOSED

With a 21 GPM flow rating, it lines up with a 21 GPM hydraulic system on paper. It is also rated up to 4600 PSI maximum operating pressure, so it is built for higher pressure work as well.

Running continuous loader cycles is well within what this valve handles. The 4600 PSI maximum operating pressure is the ceiling, and staying below it during normal duty keeps things stable. The fluid temperature range tops out at 176°F with the standard Buna-N seals, so as long as your system isn't pushing heat past that threshold, you're not going to be fighting seal degradation from prolonged use. Keep your filtration at ISO 4406 19/16 and your viscosity between 80 and 400 SSU while operating, and this thing is built to go all day without complaint.

Optional power beyond is part of this SD8 Series outlet cover setup, so you can configure it with a power beyond port when you need to feed downstream valves.

While the valve itself can handle ambient temperatures down to -40°F, keep in mind the standard Buna-N seals are only rated to -4°F. You might need to look into different seal materials if you're consistently operating below that.

Rated at 4600 PSI maximum operating pressure, so it's got plenty of headroom for most demanding closed center setups. It supports both open and closed center hydraulic systems right out of the box, and every work section comes with a load check valve built in. Internal leakage is kept real tight too, no more than 0.18 cubic inches per minute at 1450 PSI differential, so you're not bleeding off performance sitting at pressure between cycles.