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  #51  
Old 11-12-2013, 02:11 PM
AWJ Services AWJ Services is offline
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Last I heard all of the equipment I use has an engine in it so not sure what your saying has to do with what an excavator or skid is capable of hyd wise?
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  #52  
Old 11-12-2013, 02:36 PM
mxridernorth mxridernorth is offline
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Quote:
Originally Posted by AWJ Services View Post
Last I heard all of the equipment I use has an engine in it so not sure what your saying has to do with what an excavator or skid is capable of hyd wise?
Hydraulic output horsepower can't be greater than engine horsepower. My T153 has max 38 HP available so theoretically this is the maximum that you can utilize.
gpm = 1714 x HP/psi. So at 3000 psi, my machine's theoretically max flow is 22 gpm. My TL140 has 81 HP and at 3000 psi the theoretical max flow would be 46 gpm.
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  #53  
Old 11-12-2013, 06:59 PM
AWJ Services AWJ Services is offline
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Quote:
Originally Posted by mxridernorth View Post
Hydraulic output horsepower can't be greater than engine horsepower. My T153 has max 38 HP available so theoretically this is the maximum that you can utilize.
gpm = 1714 x HP/psi. So at 3000 psi, my machine's theoretically max flow is 22 gpm. My TL140 has 81 HP and at 3000 psi the theoretical max flow would be 46 gpm.
So what would the flow be at 1000psi?
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  #54  
Old 11-12-2013, 07:56 PM
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Nelson M Martin Nelson M Martin is offline
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Quote:
Originally Posted by mxridernorth View Post
Hydraulic output horsepower can't be greater than engine horsepower. My T153 has max 38 HP available so theoretically this is the maximum that you can utilize.
gpm = 1714 x HP/psi. So at 3000 psi, my machine's theoretically max flow is 22 gpm. My TL140 has 81 HP and at 3000 psi the theoretical max flow would be 46 gpm.
come on guys make it simple
max hydraulic gpm specs on all equipment are given without any load on hydraulics
Max hydraulic psi specs are given for example:: "dead heading the mulcher drum"
so the max gpm and max psi cannot be seen at the same time
Example
the harder u use the attachment on any of the machines mentioned, the higher the hydraulic pressure will rise, So (not all machines are the same) but at some point in pressure the releif valve will start to divert some of the oil back to hydraulic tank. If u stall the mulcher head to a stop the gpm at motor will be zero but the releif valve is deverting the oil into tank again
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  #55  
Old 11-12-2013, 08:53 PM
Digdeep Digdeep is offline
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Quote:
Originally Posted by Nelson M Martin View Post
come on guys make it simple
max hydraulic gpm specs on all equipment are given without any load on hydraulics
Max hydraulic psi specs are given for example:: "dead heading the mulcher drum"
so the max gpm and max psi cannot be seen at the same time
Example
the harder u use the attachment on any of the machines mentioned, the higher the hydraulic pressure will rise, So (not all machines are the same) but at some point in pressure the releif valve will start to divert some of the oil back to hydraulic tank. If u stall the mulcher head to a stop the gpm at motor will be zero but the releif valve is deverting the oil into tank again
Thank you. The original point I made was that you will not see the max hyd gpm given on a spec sheet at the advertised max psi on that same spec sheet.
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  #56  
Old 11-12-2013, 09:08 PM
mxridernorth mxridernorth is offline
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Max psi and max flow can be seen at the same time. In the example given above it's the point at which the relief valve opens.
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  #57  
Old 11-12-2013, 09:25 PM
Digdeep Digdeep is offline
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Quote:
Originally Posted by mxridernorth View Post
Max psi and max flow can be seen at the same time. In the example given above it's the point at which the relief valve opens.
Not on any SSL or CTL that I have put a flow meter on. The actual high flow near the "max" psi on the spec is not even close to the flow on the brochure.

Maybe if the engine was able to put out significantly more torque to drive the pump as the pressure builds up due to resistance from the flow meter, but the flow drops off dramatically not far above 2500psi on the Bobcats I've put a flow meter on.
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  #58  
Old 11-12-2013, 10:05 PM
AWJ Services AWJ Services is offline
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Quote:
Originally Posted by Nelson M Martin View Post
come on guys make it simple
max hydraulic gpm specs on all equipment are given without any load on hydraulics
Max hydraulic psi specs are given for example:: "dead heading the mulcher drum"
so the max gpm and max psi cannot be seen at the same time
Example
the harder u use the attachment on any of the machines mentioned, the higher the hydraulic pressure will rise, So (not all machines are the same) but at some point in pressure the releif valve will start to divert some of the oil back to hydraulic tank. If u stall the mulcher head to a stop the gpm at motor will be zero but the releif valve is deverting the oil into tank again
What started this was I stated that on mini ex's the adv flow rating( aux circuit) would be equal to the actual hp available on that circuit. It has went downhill from there.LOL
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  #59  
Old 11-12-2013, 10:08 PM
AWJ Services AWJ Services is offline
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Quote:
Originally Posted by mxridernorth View Post
Hydraulic output horsepower can't be greater than engine horsepower. My T153 has max 38 HP available so theoretically this is the maximum that you can utilize.
gpm = 1714 x HP/psi. So at 3000 psi, my machine's theoretically max flow is 22 gpm. My TL140 has 81 HP and at 3000 psi the theoretical max flow would be 46 gpm.
Using your formula

gpm=1714 x 38/1000

gpm = 65

Wow the pump mysteriously does not have a linear flow?
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  #60  
Old 11-12-2013, 10:10 PM
AWJ Services AWJ Services is offline
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Quote:
Originally Posted by Nelson M Martin View Post
come on guys make it simple
max hydraulic gpm specs on all equipment are given without any load on hydraulics
Max hydraulic psi specs are given for example:: "dead heading the mulcher drum"
so the max gpm and max psi cannot be seen at the same time
Example
the harder u use the attachment on any of the machines mentioned, the higher the hydraulic pressure will rise, So (not all machines are the same) but at some point in pressure the releif valve will start to divert some of the oil back to hydraulic tank. If u stall the mulcher head to a stop the gpm at motor will be zero but the releif valve is deverting the oil into tank again
I will add that I was told the min ex flow specs are given at 1000 psi.
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