I have a 6 X 30 cylinder with 3/8" npt ports I would like to change into 3/4". This cylinder is for use on a log splitter I want to cycle faster. Every fluid passage from the 22gpm pump through the valves is 3/4" except the cylinder, which has the 3/8" ports. My question is if I take apart the cylinder to the point where I have an empty cylinder, and I cut off the 3/8" ports and enlarge them to 3/4", finally welding 3/4" pipe to the enlarged holes, will it work to 2500 psi??? Or should i go to a hydraulic shop and have them do the hole enlarging? I should have pictures in a little bit if you would like and tell me what you think. Thanks in advance!
I've done that with grapple cylinders @ 3500 psi. I'd be tempted to change out the pipe elbows with hydraulic fittings but thats just me. Whatever fitting you weld to the barrel, make sure to remove the galvanizing or anodizing where you will be welding. I like to grind a 'saddle' in the fitting so it sits down tight to the barrel.
You might want to get rid of those two elbows. When you weld on the new 90 degree fitting, flip it 180 degrees and come straight in with the hose. Make it a little taller so you can get a wrench between the hose end and the barrel.
surplus center has weld on fittings.
No matter what you do you are still only going to get 22 gallons a minute out of it unless you change the pump.
Cut off the old 3/8" NPT weld on fitting off and weld new SAE port straight fittings of the size you want, then you can use an SAE 90 degree hyd fitting to connect to your existing JIC hose connections. http://www.baileynet.com/index.php?id=31&productcategory=1000022
as mentioned you will still have 22gpm. how much pressure do you normaly see when working? do you need a 6" cylinder? if you can go to a smaller diameter cylinder cycle times will be shorter but if working pressure is maxed out now you may have too little power to do the job and work time will suffer.
Rob, all the tips you provided on how the technique is performed correctly is awesome. Thank You!
Greg, are saying that I will not see a significant change in cycle time but just create less heat?
Nice! and the ideal parts are less then 10 bucks. very nice.
Bob, explain why I will still have only the 22gpm if you don't mind. My fluid dynamics experience only has a few years behind it, so any additional technical insight is greatly appreciated. I got that cylinder for $115, freshly resealed from this nice guy I met through ebay who was excited about the project. I want to spend as little as I have to, of course, but optimize the performance from what I have. I scavenged like hell when i put that thing together, so unless i can see a drastic difference in performance, I won't throw down the cash. I have a 32hp engine running the 1.83 cu in pump at 2800 - 3100 rpm's I will look around for some pics of the engine / pump and valves to post as well. Thanks in advance.
If you have a 22 GPM pump at XXXX Rpm, the only way to get more flow is to get more RPM, but there is a limit due to the flow into the pump, too high RPM can cause cavitation and eat up the pump.
sorry, my specs of the pump were vague, sorry about that. here is from the web page: ( http://www.surpluscenter.com/item.asp?item=9-7795-A&catname=hydraulic ) SPECIFICATIONS * Disp. 1.83 cu. in. / rev. * Pump Type Gear * Rotation CW * Pressure: 2300 PSI peak * Speed: 2000 RPM rated 3600 RPM max. * Flow: 14.74 GPM rated 26.52 GPM max. * Inlet Port SAE 16 * Outlet Port SAE 12 So, if I am running it at 2800rpm I should get about 22gpm (rpm x displ / 231), or at least that is what i am hoping when i open the cylinder's ports up a few times larger.
Your flow is being restricted by your control valve....what are the flow specs for it? 22 gpm is 22 gpm,and plenty at that for a log splitter.You probably want a faster return stroke,which means you are using the wrong cylinder for your application (You need a smaller cylinder) and for the love of God,get rid of that black pipe in the pressure side of your rig.
I put in the prince auto cycle valve not to long ago which is rated at 25gpm. Down stream is my old cross valve, which is just rated at 30gpm, but only controls the log lift currently. Granted I think i might like the novelty of the over done cylinder, but it also does not have any power limitations which is nice. So basically i just want things to go as fast as they can with what i have. Oh, and the black pipe on the right side of the valves is going to have my drink holder on it eventually.
for a quick diagnosis i would read pressure at the pump on both strokes with no log. there should be very little pressure. if pressure is too high the small fittings on the cylinder may be restricting your flow and not allowing the 22 gpm we want to see in no load. you got a bunch of plumbing on there and every fitting that you can do without will help flow. 90 degree fittings are the most restrictive. now if there is little pressure on both strokes without a log, your maxed out and need more pump flow or a smaller diameter cylinder. also, you may not have noticed but some fittings are very restrictive due to the small id they have. proper diagnosis on this project will save you time and money.
Well bobb, that answers that. The auto cycle valve is set from the factory: first spool 1500psi, second is 1700psi..... If the splitter is hitting into a really hard piece of wood, and if i don't hold my hand on the valve lever, it'll pop right out and return cycle without splitting. Thanks for explaining why that is happening.