Hose Size for 10 GPM ?

   / Hose Size for 10 GPM ? #1  

keeney

Veteran Member
Joined
Dec 2, 2001
Messages
1,060
Location
Minnesota
Tractor
JD 4100 HST
I am looking to add an auxialary hydraulic pump and control valves to my tractor so I can use hydraulic attachments designed for small skid-steers and mini-loaders. These attachments are more readily available than PTO-driven 3-pt ones at rental yards in my area.


A lot of these attachments need up to 10 gpm at 3000 PSI (more gpm for the larger ones, but my tractor only puts out 16 PTO HP).

I have a 10 gpm pto pump, and some 20 gpm control valves. Now I just need to hook it all up. What is an appropriate hose size for 10 gpm?

I want to use 3/8" to make routing of the hoses easier, but I think I might need 1/2" or larger to avoid too much heat buildup at full flow. Any opinions?

- Rick
 
   / Hose Size for 10 GPM ? #2  
Rick, I'm not sure about the hose sizes, the front remote lines on my NH Skid Steer look to be about 1/2" ID...about 3/4" OD...haven't had to take one off to check!

but...

Have you looked into the weight of the attachments that you are thinking about renting...most skid steer attachments that I have seen/own weigh in around 800 lbs. for the lighter ones....the average is probably closer to 1200 lbs...on a smaller tractor, after/if you lift the implement...it doesn't leave a lot left over for what you are trying to move /forums/images/graemlins/blush.gif

Just a thought....

GareyD
 
   / Hose Size for 10 GPM ? #3  
3/8 will run 10 gpm without any trouble. 1/2 if you end up running over 12 gpm.

if your worried about you system getting hot, run an extra large oil tank

10gpm, you need atleast 10 gallons.
 
   / Hose Size for 10 GPM ? #4  
As previously stated, 3/8" inside diameter will work just fine. Make sure that the pressure rating of the hose is sufficient for your system. A good 2-wire hose will be rated for at least 4000 psi and I would not use anything less even if your system pressure is lower.
 
   / Hose Size for 10 GPM ?
  • Thread Starter
#5  
<font color="green"> Have you looked into the weight of the attachments that you are thinking about renting...most skid steer attachments that I have seen/own weigh in around 800 lbs. for the lighter ones....the average is probably closer to 1200 lbs...on a smaller tractor, after/if you lift the implement...it doesn't leave a lot left over for what you are trying to move </font>

Garey,

I am mainly interested in things like a trencher, vibe-plow, a tree auger, power rake, tiller, that sort of thing. Most of these (except maybe the tree auger) don't lift that much payload other than their own weight.

The mini-load attachments like for the Bobcat MT-52 or the Toro Dingo TX425 are nice and small. The lift capacity of the Dingo is only 500 lbs. These are more the right size for my tractor and are about half the price per day to rent as well. I am concentrating on the mini-loader mount plate adapter first, and the full-size skid-steer mount adapter may come later.

My 4100 can lift about 1200 lbs to a couple of feet and almost 900 lbs to full height, including the bucket, so I think anything under 1000 lbs will still be usable.

I am also looking at putting a mount plate on the three-point hitch for using the trencher and tillers. The three-point can lift 1100 lbs or something.

- Rick
 
   / Hose Size for 10 GPM ? #6  
keeny,

A quick web search on hydraulic horsepower conversion showed that 10 GPM @ 3000 psi is 17.5 HP. You may be disapopointed on the bigger implements.

John
 
   / Hose Size for 10 GPM ?
  • Thread Starter
#7  
Yes, I know that the 16 PTO HP will be marginal, but the idea is to make the best use of the tractor I have. By the time you sacrafice a few HP on the alter of hydraulic inefficiency, it is clear I will not really be able to obtain 10 GPM at 3000 PSI.

Because I am short on total input power, I am concerned with every little efficiency issue such as losses in the hoses. If I burn 10% of my power in the hoses and I can switch to a larger size and reduce that to 4%, It might be worth the few more bucks for the larger hoses and fittings.

Given this under-powered scenario, I have actually selected a pump displacement that yields just over 7 GPM at 540 RPM but does not require more torque than my tractor can deliver. If I rev up the RPMS by another 10% to 600 RPM at the PTO, I can get close to 8 GPM assuming enough torque to drive the required pressure.

So the attachment will operate 20% to 30% slower.

I can live with that.

- Rick
 
   / Hose Size for 10 GPM ? #8  
Check out baum hydraulics . If I did that link stuff right it should take you to their site for hydraulic calculators. They are great folks to deal with also.
Wayne
 
 
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