I'm restoring a 1968 50 ton detachable gooseneck. Someone 'fixed' the hydraulics with whatever was handy and I'm trying to redo it correctly. Starting from scratch. It uses two huge rams to raise/lower the bed. Question: in routing the hydraulics, do I need to install a flow restrictor so that when I lower the bed, it doesn't just go 'ker-flop' on the ground? I understand that there are two types of restrictors. One is just that, and the other one restricts in one direction and free flows in the other, which is, I think, what I want. That allows me to raise the bed fast, but it would drop slowly. I cannot find general information about hydraulic design anywhere. I would like to see a hydraulic diagram for a RGN trailer if anyone has one. Thanks. Dirtmaster
Hello Dirtmaster, RE: flow controls for your trailer, Yes you are correct. Parker fittings offers both styles, the one you are thinking about is the "F" Series flow control valves. They have an internal check valve that allow free-flow in one direction and there is an adjustible knob that allows you to adjust the oil flow in the other direction. The valves are offered in both female Pipe and SAE ports depending on your preference. I would suggest contacting your Parker hose dealer. A note on flow-controlling cylinders or motors. This practice will eliminate your systems relief valves ability to prevent overload pressures and can cause an overload failure which will be an dangerous and a expensive issue to fix. Be sure that your trailer's cylinder loads will not cause such a problem. Good Luck
Good point. I could install a relief valve in parallel with it,I suppose.