I'm going to be mounting the ripper soon and was wondering about the hoses. The ripper appears to have a couple short 3/8" hoses for hookup. I'm going to use the old wing valve to control the ripper. It has 1/2" JIC connections. I thought about using 3/8" hoses because they are more compact and easier to route in the center of the machine at the articulation pivot point. I think there is an issue though because the hoses need to be about 13' long which I think could cause multiple problems. Am I best to go with 1/2" hoses and make a mount for bulkhead fittings to go the short hoses on the ripper?
It's all about flow rate. 3/8" hose 13' long would flow about 9 gallons/min at about 1000 psi. Estimate the volume of your ripper cylinders at the head end, fully extended, divide that into the 9 gpm and you can work out your cycle time. Obviously, 1000 psi is a conservative figure. I think you will be OK.
Thanks so much for your insight Cmark. I talked to the hyd. shop and they suggested I go with the 1/2" hose because of the length but I'm not sure how much flow the valve flows. Looking at an old spec. sheet for the valve it's normally rated for 12 GPM but says to contact the factory for higher flow rates. I think 9 GPM would be fine for the ripper but there are 2 cylinders instead of 1 so it would be slower although would the existing 3/8" hoses already limit the speed? About the only time the pressure would max. out is when the cylinder is fully extended or retracted which would be for a very short time. The valve on the ripper is a combination cushion valve and lock valve so should protect things. Just for controlling the ripper do I need to worry about increased heat or turbulence in the hoses that could potentially cause issues? I looked at some 1/2" hoses and the standard 2 wire hose rated for 5000 PSI is too stiff. I could get that hose about 1/3 cheaper at another place.They also had a 2350 PSI hose that you could tie in a knot. That's the hose I'd use since it has a 4-1safety factor. I never checked what the flexible 3/8" hose is rated for but smaller hose is usually rated for higher pressure for the same type of hose. Now I'm wondering if I should just go with the 3/8" hose? It would be easier to snake around like I need to. I considered using hyd. tubing along the rear frame but it would cost a bunch more especially if it had some bends. I'm going to tack some steel brackets for plastic hose supports along the inside of the frame and make a bracket for bulkhead fittings at the back where the ripper hoses tie in. I thought about 1 piece hoses but I think it's better to have a simple way to disconnect the ripper if I ever needed to.
Cats come with 3/8 hose if that helps any ripper is generally not a high speed need that you require a large flow rate
Do you know how long Cat hoses for a ripper are? Would I lose much pressure with a 12 to 14' 3/8" hose? Looking at specs. for a similar ripper the cylinders are 4" dia. with a 17.25" stroke. At 9 GPM it would take 6.2 seconds for 1 cylinder to fully extend so 12.4 seconds for both to fully extend. I found refence that 3/8" hose will flow up to 8 GPM which slows the extend time to 13.8 seconds. I'm guessing the flow velocity being too high (based on established hyd. recommendations) isn't a big concern for an intermittent application like a ripper? I thought it might be a dumb question originally but now it has me perplexed about the best size of hose to use.
You don't lose any pressure with a smaller dia line, you lose flow. The 1000 psi example I quoted was conservative. Not knowing the grader, but let's say it can make 3000 psi which is a reasonable industry standard for that kind of machine. That would bring the flow through 13' of 3/8" hose up to maybe 14 gpm. Now whether the machine's pump or control valve is capable of delivering this much flow is another thing. For me, heat isn't a concern in this application. If the cylinder was in a constant cycle like for example a concrete pump, I would perhaps consider going for 1/2" lines. In this case however the ripper will maybe cycle once or twice a minute at most? For reference, a Cat 140H 126 prefix has about 14'3" of 3/8" hose from the control valve to the rear bulkhead fittings.
I think the highest setting is 2500 PSI and 2100 is also used. Thank you for steering me in the right direction. I will go with the more flexible 3/8" hose. It will look tidier too with the smaller hose.
We did some measuring and it looks 14' will give plenty of length so there's no binding or pulling. It's better to be a little long than too short.