# When my log splitter piston gets very hot....



## crowbait (Jul 30, 2007)

It would seem to me that the higher the tonnage of a log splitter, that the hotter it will get. No? I would think that as the pressure goes up, you're asking the hydraulic oil to do more work, and thus more heat is generated. Is this true?


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## BC_Logger (Jul 30, 2007)

more pressure, more oil, more heat

the more oil you cycle more heat will be transfered


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## crowbait (Jul 30, 2007)

So, the best way to reduce the heat, is to increase your tank size, thus giving your oil more "surface area" for cooling....yes?


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## Dadatwins (Jul 30, 2007)

Increased tank size and the right oil for the tank. Hydro oil has different grades like engine oil, use the cheap stuff and you will have problems.


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## mga (Jul 30, 2007)

TreeCo said:


> ....but......but it's all in the design. I have a 45 gallon hydraulic tank on my splitter.....and it stays cool.



45 gallon????

gees...i complained about filling my 18 gallon tank!!


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## Frank Boyer (Jul 30, 2007)

crowbait said:


> It would seem to me that the higher the tonnage of a log splitter, that the hotter it will get. No? I would think that as the pressure goes up, you're asking the hydraulic oil to do more work, and thus more heat is generated. Is this true?




Most splitters run in the 2200-2500 psi range. The extra power comes from a larger ram. As the pump/motor size goes up the line size and reservoir size go up. A well designed system should not have a problem.


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## drmiller100 (Jul 30, 2007)

actually the heat COMES from inefficiencies.

so, lets say at peak pressure your pump is 85 percent efficient.
that means 15 percent of the power is covnerted to heat at peak pressure.

at lower pressures, efficiencies almost always go up. larger tank means more heat transfer, more mass, less ultimate peak temperature.


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## sawinredneck (Jul 30, 2007)

But a well designed Bobcat, can flow 18gpm with a 22 gallon hyd. res., how is that? And, the Hydrostat system never runs back to the resovoir? Want to talk about flow now?

Again, I must be stupid.

Yes, more fluid helps, but desining the system right, helps most.


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## STEELHEAD (Jul 30, 2007)

*talkin about flow*

On most all hydrostatic drives , like bobcat, a portion of the oil goes back to the tank , for filtering and cooling, almost ALL commercial hydraulic units are fitted with oil coolers like the bobcat.


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## SmokinDodge (Jul 30, 2007)

crowbait said:


> It would seem to me that the higher the tonnage of a log splitter, that the hotter it will get. No? I would think that as the pressure goes up, you're asking the hydraulic oil to do more work, and thus more heat is generated. Is this true?



It all has to do with surface area of the piston in the ram. A 25 ton splitter runs at the same pressure as a 30 ton (generally speaking) but the larger diameter of the piston allows for more splitting pressure with the same hyd system pressure. 
The formula for figureing tonnage is Force=Pressure x Area, if you increase the area the fluid has to act on you will net a higher tonnage.


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## leon (Jul 30, 2007)

crowbait said:


> It would seem to me that the higher the tonnage of a log splitter, that the hotter it will get. No? I would think that as the pressure goes up, you're asking the hydraulic oil to do more work, and thus more heat is generated. Is this true?



 
A machines duty cycle and seasonal temperature norms determines oil operating temperature. The more it is used the hotter it will become and hence the more efficient.

When hydraulic oil becomes cold it becomes more dense and is very difficult to pump-with a lot of processors the pump is directly driven off the flywheel and, one its an easy installation and, two it is harder to start an engine without a Rockford or other type of power take off. 

Big engine starters have huge amperage and huge cold cranking amp batteries either in series for a larger voltage or parallel for higher cold cranking amperage as a rule.

Hydraulic oils have varying capacity at various temperature-the lower the viscosity of hydraulic oils the greater the heat transfer and the more efficient the oil is at delivering pressure and force to the cylinders of a processor or log splitter.

This is why they want you to warm up machines before using them- me I use a salamander to heat up my log splitter when the weather gets cold-it runs so much better after a warm up like that.

The hotter the hydraulic oils is = maximum operating temperature the more efficiently it delivers total hydraulic power/force at its maximum. 

Bobcats have Cessna closed center bent axial hydraulic piston pumps which are the most efficient and deliver the most power in a small package at the time of delivery.

Gear pumps are the least costly and the lowest efficient method of delivering hydraulic pressure, vane pumps are the next most efficient and deliver better cold weather performance simply from its design and then the top of the line pump is the piston pump which is either the bent axial pump or inline piston pump. 

A good hydraulic oil for any weather is a ten weight hydraulic oil. engine heaters do wonders for hydraulic oil systems as the heat is transfered indirectly via the metal components in the engine.


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## sawinredneck (Jul 30, 2007)

STEELHEAD said:


> On most all hydrostatic drives , like bobcat, a portion of the oil goes back to the tank , for filtering and cooling, almost ALL commercial hydraulic units are fitted with oil coolers like the bobcat.



Hence "well desinged"!


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## triptester (Jul 31, 2007)

Proper design of the system is very important when trying to control heat build-up. My brother had a splitter with a single stage 7 gpm pump and 20 gallon reservoir. After 2 hours of use the tank would be uncomfortably warm to the touch by simply changing the hoses and type of fittings used the temperature dropped to barely warming the tank.

He found that the fittings greatly restricted the flow causing the heat build-up.


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## leon (Jul 31, 2007)

*oil oil every where*



triptester said:


> Proper design of the system is very important when trying to control heat build-up. My brother had a splitter with a single stage 7 gpm pump and 20 gallon reservoir. After 2 hours of use the tank would be uncomfortably warm to the touch by simply changing the hoses and type of fittings used the temperature dropped to barely warming the tank.
> 
> He found that the fittings greatly restricted the flow causing the heat build-up.



I would be willing to bet he had a herd of regular 90 degree fittings plumbed into the tank rather than sweep 90 degree gooseneck fittings. he may have had a collapsed hose or two as well as rubber hose is famous for that due to the inner rubber tube which is surrounded by the wire reinforcement-did he change both the pressure and suction lines to the valve body?


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## mga (Jul 31, 2007)

a good web site for hydraulic information. you can sign up for a free weekly letter and/or search the data banks for alot of info:

http://www.insidersecretstohydraulics.com/?Hydraulic+fitting


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## triptester (Jul 31, 2007)

leon said:


> I would be willing to bet he had a herd of regular 90 degree fittings plumbed into the tank rather than sweep 90 degree gooseneck fittings. he may have had a collapsed hose or two as well as rubber hose is famous for that due to the inner rubber tube which is surrounded by the wire reinforcement-did he change both the pressure and suction lines to the valve body?



The original fittings were JIC bent tube 90's on the pressure side . After close inspection he found the fittings had 1/8 inch smaller I.D. than the hose. The only change made was new high pressure hose and fittings.


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## leon (Jul 31, 2007)

triptester said:


> The original fittings were JIC bent tube 90's on the pressure side . After close inspection he found the fittings had 1/8 inch smaller I.D. than the hose. The only change made was new high pressure hose and fittings.



They must have been single wire braid then as a double wire braid hose fitting would not deform like that unless it was a hydraulic press on fitting that was damaged/swaged improperly- was there a ridge along the top of the old fittings?-this would be a definite indicator of a bad hose job.

:chainsawguy:


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## triptester (Jul 31, 2007)

I dug through my collection of hydraulic fittings and compared the inside diameter of the fittings. For 1/2" hose fittings with a NPT or strait thread the I.D. was 7/16" while the JIC flare fittings had only 5/16 I.D. . This restriction between pump and control valve will effect heat build-up greatly. Other locations should not be as greatly effected.

Another major cause of heat is cavitation when air is added to the fluid by just dumping it into the reservoir with the return line rather than keeping the return submerged.


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## Al Smith (Jul 31, 2007)

In addition to what has already been mentioned,a cylinder that is bypassing will get hot enough to fry an egg on,ouch.Type A,tranny fluid, is about the best for usage in most hydraulic systems used for wide variations of ambiant temperatures.In addition,a smaller cylinder has tendency to get a lot more heat generated than a larger cylinder applying the same tonnage force.

The working side of the cylinder is only going to be under whatever amount of pressure it needs to move it through the wood.Obviously it would require a lot more pressure to move a 3.5" through a big gnarly chunk of oak that it would for a 5" cylinder.

Another often overlooked item is hose or line sizes restricting flow.A 3/4" line has twice the area of a 1/2" line and a 1" has 4 times the area.What has already been mentioned about 90 degree fittings holds very true.It takes a lot more effort to shove oil around a turn than pushing it straight.In the design of most industrial hydraulic applications,the steel lines are bend rarther the use of fittings are kept to a minimum.These are open center systems,in other words the lines are always under pressure with the relief usually in the bypass condition.

More times than not these systems use large lines and large cylinders rated at 3,000 lbs or over but ran at around 800 psi.Running at this lower pressure increases the life of the components by about 10 fold.


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## Al Smith (Jul 31, 2007)

While this discussion is still going on another thing popped into my pea brain.Often times the wear plates and gears,pump bodies of gear pumps get worn to the point the pump internally bypasses.The vains can also become worn in vain pumps and the pistons and squish plates become won on Vickers piston pumps.

No pump is 100 percent efficient but some more so than others.If and when a pump bypasses internally it has the same effect as a cylinder bypassing in that heat will be generated into the fliud,it has no other place to go.By and large the pumps used on most splitters are not rebuildable.The only cure ,if the pump is bypassing is to replace it,that being the case.


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## fast*st (Aug 6, 2007)

I have a quick and bizarre question, okay maybe not quick. 
I have a splitter that someone made from pieces and parts. 
Its running a 18.5 Wisconsin engine but only a 10gpm pump, 
I was thinking of upgrading the pump and lines and to a
22-28gpm dual stage. I don't want it to run too hot but
well, it has an 8-9 gallon tank. 

Right now with the V10 vickers it runs hot after a few 
hours. As noted earlier, there are 8 90 degree elbows
and some wacky fittings. The fluid end of the ram has 
two aluminum blocks 3x4x1, One on the extend port and 
one on the retract, it looks like there's a pressure regulator
with a crossover tube to the other chamber? The crossover
tube comes out opposite what looks like a pressure adjusting
bolt. My WAG is that in its previous life, those regulators allow
the ram to settle in case some amount of force is exceeded?
I'll consult with a hyd repair shop if its okay to remove them. 


The Wisconsin engine has a turbofan flywheel, blows air 
about 10 feet out from the engine. I was thinking of doing 
a little ducting, stealing some air from the fan shroud and 
picking up an oil cooler off a Cessna from fleabay, they can
be had for about $30 or so, are full flow and would be sweet 
in the return line. I don't have room to add another large 
oil tank to keep up with a 28gpm pump. This seems like it
would cost about $50 to install, wouldn't take long to put 
on and would remove a lot of heat. 

Any thoughts? and having a 18hp splitter with 9.00x19.5 tires 
and budd wheels is cool 

-Jason


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## triptester (Aug 6, 2007)

An oil cooler will help cool the oil but does not aid in removing trapped air which requires a properly designed tank. Most residential log splitters only have a 5 to 7 gallon reservoir. Timber wolf commercial splitters use a 15 gallon tank with a 22 gpm pump and a 20 gallon tank with a 28 gpm pump. None of these splitters use oil coolers.

A properly designed tank will put the maximum distance between supply and return both of which must be completely submerged at all times. A long narrow reservoir will be much more efficient than a square cube of the same capacity when it comes to cooling and removing air.

Control valves , hoses, and fittings must all have adequate capacity to handle the maximum flow with minimum friction which causes heat build-up.


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## fast*st (Aug 6, 2007)

This splitter uses an air tank from a big truck welded to the I beam. The
builder did use a bottom suction and return, any other ways that
air would get into the system once purged? 

-Jason


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## leon (Aug 6, 2007)

fast*st said:


> I have a quick and bizarre question, okay maybe not quick.
> I have a splitter that someone made from pieces and parts.
> Its running a 18.5 Wisconsin engine but only a 10gpm pump,
> I was thinking of upgrading the pump and lines and to a
> ...



It sounds as if the cylinder has two flow control and relief valves with a pressure regulated bypass relief and was scavenged off of an aerial lift or bucket truck. trying to steal outbound cooling air of the top of the engine is really not a good idea as the engine head has to be clear for proper ventilation cooling.

Small oil coolers with 12 volt integral fans are not that expensive.


If you could send close up pictures of the valves that would help.


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## fast*st (Aug 6, 2007)

I'll try and get some pics tonight. I was thinking about that whole stealing cooling air but the volume that comes off the flywheel fan (14" dia) is 
quite a bit, and even moreso after I removed several years of mouse nests. 
Seems to be well over engineered in the Wisconsin tradition. 

I wouldn't think much air would be needed with a good radiator, and yes,
a thermostatic 12v fan would probably do nicely. No sense adding cooling
during the winter. 

I'd also love to remove as many 90 degree fittings as possible and 
replace them with sweeps or straight fittings. 

-Jason


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## ziggy2b (Aug 6, 2007)

*fluid*

My splitter uses transmission fluid, just and idea? It has to be cheaper?and operates in that temperature range.:bang:


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## leon (Aug 6, 2007)

*asplitting we will go*



fast*st said:


> I'll try and get some pics tonight. I was thinking about that whole stealing cooling air but the volume that comes off the flywheel fan (14" dia) is
> quite a bit, and even moreso after I removed several years of mouse nests.
> Seems to be well over engineered in the Wisconsin tradition.
> 
> ...



:chainsawguy: :newbie: 

Greetings and salutations from my corner of the soon to be frozen eastern wilderness @ 1140 feet above mean sea level.

If the ninety degree fittings are at the valve body ports there is no need to change them as they are only moving oil when the valves are moved-if there is a box ninety degree fitting in a constant flow path such as the pump presssure outlet change it if possible as it is adding resistance to the oil flow but remember that sweep ninety degree fittings are not a problem, the hotter the oil is the more efficient the log splitter is.


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## fast*st (Aug 6, 2007)

Yeah, I'm going to try and get a pic, the hose ended in a 90 elbow(both ends), into another 90 elbow into a T fitting and another 90 turn into the block, 90 down into the fluid end of the ram, so 720 degrees of bend from the valve to the pump. I could easily replace every bit with 3/4 hardline, save for two
couplers between the valve and the ram to allow a little flex. Every less turn and every reduction in flow velocity is just a little less friction loss and a little less heat. I suppose, apply some engineering before brute force. Maybe sandblast or wirebrush the ram body clean and give it a single coat of bright yellow paint to help it shed heat as well. 

Loaded the ram with help into the back of the truck, off to repair in the morning. 

-Jason


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## leon (Aug 6, 2007)

*woodsplitter*



fast*st said:


> Yeah, I'm going to try and get a pic, the hose ended in a 90 elbow(both ends), into another 90 elbow into a T fitting and another 90 turn into the block, 90 down into the fluid end of the ram, so 720 degrees of bend from the valve to the pump. I could easily replace every bit with 3/4 hardline, save for two
> couplers between the valve and the ram to allow a little flex. Every less turn and every reduction in flow velocity is just a little less friction loss and a little less heat. I suppose, apply some engineering before brute force. Maybe sandblast or wirebrush the ram body clean and give it a single coat of bright yellow paint to help it shed heat as well.
> 
> Loaded the ram with help into the back of the truck, off to repair in the morning.
> ...




  

Jason-do not worry about shedding heat off the cylinder it is actually a very good radiator for same. If the ninety degree fittings serve no purpose- directing hose around obstructions for example it is safe to remove them and replace it with a good hose or steel hydraulic line-be sure to secure it with loom clamps sized to the pipe other wise it will vibrate a lot and reduce its useable life. 

leon


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## fast*st (Aug 7, 2007)

Okay, think I have the picture correctly attached? Not entirely sure, this is the fluid end of the ram, input fittings sticking straight up. 

lots of bends!


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## leon (Aug 7, 2007)

*wood splitter etc.*



fast*st said:


> Okay, think I have the picture correctly attached? Not entirely sure, this is the fluid end of the ram, input fittings sticking straight up.
> 
> lots of bends!



You appear to have a cylinder with a pair of pilot operated check valves and welded pipe to the cylinder which is common.
The cylinder should have ID numbers punched into the barrel near the base or near the packing gland. the aluminum blocks should have an ID no. on the side of the block or the tag riveted to the block depending on who made the control valve.



This cylinder is from a bucket trucks bottom lift arm if I am not mistaken.

For your piece of mind I would contact Racine and give them the part number so you can get information on the control valves and cylinder-am I correct in assuming the top oil port of the cylinder has the same equipment/valves? can you flip the picture next time as it is actually upside down?


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## fast*st (Aug 7, 2007)

That's the fluid end, and its not upsidedown, that's how it was 
sitting in the truck  The top and bottom ports are side by side
with a hardline beneath. The hydraulic shop seemed to indicate
much the same, this cyl has the safety that it won't lower 
unless there's forward pressure on the other side. 

I'd love to remove the 4 allen bolts, remove the blocks and 
just put a regular pair of 90 degree sweeps on it. I don't see
the need to have a safety lockout on a log splitter, at worst
if a line fails the log falls on the ground and I get a hot oil bath. 
I'd love to decrease any flow restriction before going 3x on the 
hydraulic pump. 10-28gpm


Thanks for the info though, its interesting finding out about this 
stuff. 

-Jason


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## GRAYSTONE (Aug 7, 2007)

*Hot Splitter - Cooled Off*

My splitter fluid ran very hot when I installed a new 13 HP Honda Engine with a 20 GPM pump. I changed the lines from 1/2" to 3/4" and increases the resevoir from 5 gallons to 15 gallons. The Oil now runs at 120 to 140 degrees F.
I do have a number of 90 degree fittings in the lines. Please have a look at the pictures and let me know if these are ok.


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## triptester (Aug 8, 2007)

The biggest concern is that it looks like the motor exhaust is in the direction of the tank.

Is the return line submerged in the tank? If the return line just spills into the tank it adds air to the fluid which will add to heat buildup.


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## GRAYSTONE (Aug 8, 2007)

*Wood Splitter Heat*



triptester said:


> The biggest concern is that it looks like the motor exhaust is in the direction of the tank.
> 
> Is the return line submerged in the tank? If the return line just spills into the tank it adds air to the fluid which will add to heat buildup.



The exhaust on the Honda Engine is actually pointing straight up away from the tank and the return line runs down into the tank about 12 inches so I'm sure it is not adding air.

The Splitter now runs very well.


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## triptester (Aug 8, 2007)

TreeCo said:


> I'm aware that air in the system causes cavitation and eats away at the pump and valve but how does air add heat to the system?



I am not a hydraulics expert and I don't fully understand the why and why nots of fluid dynamics but this is what the experts say.

Why is entrained air bad? 
Negative effects of entrained air include: 

Reduced bulk modulus, resulting in spongy operation and poor control system response. 
Increased heat-load. 
Reduced thermal conductivity. 
Fluid deterioration through increased oxidation and thermal degradation (dieseling). 
Reduced fluid viscosity, which leaves critical surfaces vulnerable to wear. 
Cavitation erosion. 
Increased noise levels. 
Decreased efficiency


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## triptester (Aug 8, 2007)

Graystone, 
Temperatures of 120 - 140 degrees may be caused by normal friction and inefficiencies in the system. When temperatures approach or exceed 180 degrees the fluid starts to break down.


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## fast*st (Aug 8, 2007)

I'd imagine as well, make sure you have a big enough supply 
line, you can't pull a fluid. Fluids can only be pushed in a 
practical sense. With air pressure being the only pusher, I could
see where cold oil won't want to flow into a pump at 30gpm 
through a 1" suction line. Water contamination would be a 
problem as well, in humid and varying environments, condensation
could well put a fair bit of water in the storage tank. 

120-140F is within the optimum temperature range, if the temps
reach 200, the viscosity keeps dropping and its suspect that the
pump will loose some efficiency and convert even more energy to 
heat. Too thick of a viscosity will of course cause cavitation and
other issues. 

As to air, most hydraulics have an anti foaming component, hydraulics
and air never mix well. Air adds heat by reducing the effectiveness of 
the pump and pumping system, pump works harder and fluid doesn't flow
as well, foamy oil has more insulating properties and won't shed heat as
fast. 

Waiting for the hydraulic shop to call on big yellers pusher. 

-Jason


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## leon (Aug 8, 2007)

*wood splittter plumbing*



GRAYSTONE said:


> My splitter fluid ran very hot when I installed a new 13 HP Honda Engine with a 20 GPM pump. I changed the lines from 1/2" to 3/4" and increases the resevoir from 5 gallons to 15 gallons. The Oil now runs at 120 to 140 degrees F.
> I do have a number of 90 degree fittings in the lines. Please have a look at the pictures and let me know if these are ok.



 opcorn: :newbie: 

I would change the fittings and hose on the pressure side of the valve body-the rightside in the photografph as the oil is cavitating across the flow path of the valve-the center part of the valve that provides the oil to the valve spool - the piping/hose and fittings should be sized to the valve body ports-the return line to the tank is the proper size but the pressure size is the problem simply due to the tremendous pressure involved and eliminate the ninety degree fitting with a sweep gooseneck with the same size fitting identical to the oil port size and the splitter with thank you for it with thousands of hour of trouble free operation unlesss and only unless the pressure side of the pump is that size-smaller- it will work fine but the pump will have more resistance.




 opcorn:


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## fast*st (Aug 12, 2007)

After scoping out tanks, I have a couple restrictions, I can do 11
wide, 36 long and up to 20 deep. That would give a max tank 
capacity of about 34 gallons, I would be comfy with 30 for a 28
gpm pump. I have a nice TIG unit someone gave me a while ago, 
I've stuck some aluminum bits together but think that making a 
tank will be fun, my neighbor has a lot of 1/8 aluminum sheet he
wants to see put to good use, I think that'll make a fine tank. 

3" npt suction with 50gpm strainer. 1.25 suction line, 1" return
line fitting with a snazzy lhf filter. Will make the brackets out of steel and 
then insulate them with rubber to keep everything happy. 

I'm thinking flange mount fittings as I can't seem to find a 3" npt 
fitting that'd just thread in with an oring. 

-Jason


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## leon (Aug 12, 2007)

fast*st said:


> After scoping out tanks, I have a couple restrictions, I can do 11
> wide, 36 long and up to 20 deep. That would give a max tank
> capacity of about 34 gallons, I would be comfy with 30 for a 28
> gpm pump. I have a nice TIG unit someone gave me a while ago,
> ...





:chainsawguy:  :newbie: 

Greetings and salutations Jason from my corner of the soon to be frozen "Eastern wilderness" @1140 feet above mean sea level.

Are you using BSP fittings or SAE fittings?

If you have not bought or unpacked the fittings please wait as you really only need a number 20 (1 and 1/4 inch suction from the tank for that pump.

Are you sure you want a number 48 size (three inch) suction line going to the pump?
flooded suction is the best scenario for your pump which will eliminate anyy air bubbles and cavitation going into the suction side of the pump. 

These hose fittings are typically a barbed fitting with an SAE flange with a 32 or 36 or 48 o-ring or larger.




A three inch BSP british standard pipe fitting which would require an o-ring to seal it will be a problem as they will be metric.





A number 24(1 and one half inch)or 32 size(2 inch) hydraulic fitting would be the better way to go for your plumbing and finding fittings will be easier; as long as the suction side is unrestricted the presure side will have no problem with the smaller sizes as a lot of fluid will go through a small pipe or hose.


leon


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## fast*st (Aug 12, 2007)

got me a little confused there, sorry for leaving the details out, 
the Donaldson P562271, P562272 strainers each fit a 3" NPT
fitting and reduce it down to a 2" NPT, getting the 1 1/4 suction 
line from there should be easy. I'm guessing that standard US
pipe thread is SAE? I think I want to go with a tube type fitting as
I can't see being able to wrangle a inch plus hydraulic suction line
free from a barb. It took me 10 minutes to get a 1/4 inch gas line
off a barb today. If someone has some information, I'd be much 
obliged. Does someone make an aluminum 3" npt female thread 
flange mount or weld in. Even a bulkhead fitting should be fine. 

As a last option, one made of brass or steel might work. 
-Jason


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## triptester (Aug 12, 2007)

Somewhere in the suction line you will have to deal with barb fittings because a flexible connection will have to be made between tank and pump. The 28 gallon pump usually comes with a 1 1/4" barbed fitting for suction.

I know there are a lot of rule of thumb figures out there but I have looked at all the spec's I could find for various makes of commercial heavy duty splitters and most use 3/4 gallon of tank capacity for each gallon of pump capacity. Hydraulic fluid around here has been running 5 to 6 dollars a gallon. Fluid changes can get real expensive. I would put a drain valve in the bottom of the tank instead of just a plug. It will make life a lot easier if you have a leak or need to change fluid.


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## leon (Aug 12, 2007)

*log splitter*



fast*st said:


> got me a little confused there, sorry for leaving the details out,
> the Donaldson P562271, P562272 strainers each fit a 3" NPT
> fitting and reduce it down to a 2" NPT, getting the 1 1/4 suction
> line from there should be easy. I'm guessing that standard US
> ...





:chainsawguy: 


Jason US pipe is "National Pipe Thread", a different animal.


3 inch hydraulic fittings and adapter are very very expensive, in the hundreds of dollars; were these items something you bought or were they salvaged?
The reason I asked is simply that the proper size strainers are not that expensive and are a common item, as they are exactly like a drop in filter cartrige housing for an oil filter or fuel filter for a diesel engine. 

The money you could spend on one fitting could buy you a proper hydraulic tank.


The three inch port for the suction strainer will move huge amounts of oil through your system all at once as there is no stopping it from entering the fitting/strainer. For a pump with a 3 inch gear or vane housing that is fine but not for a small log splitter as a huge surge of hot oil that is not allowed to cool a bit is not good for the pump and air bubbles will not be allowed to disolve, besides the fact that a huge vacuum can be created by the movement of the oil if you do not have a proper breather vent for the tank-and baffles, that is why I suggested buying complete tank ready to mount and plumb as everything will be there; your hydraulic shop can help you with this if they value your business. 

If you buy the fittings and strainer from your hydraulic rebuild shop the fittings will be correctly sized for the suction side of the pump. The last time I looked northern tool had hydraulic tanks for sale and hydraulic tanks come in many sizes and shapes perhaps this is an option for you-but I would not buy fittings and a strainer from them as they are not involved with hydraulics as a main business and that will cost you time and money especially if they send the wrong items-they did that to my brother once regarding a replacement engine for a lawnmower-they did not ask for the engine serial number, type, series etc and he had to hav ethe shaft cut to the proper length-his own fault but-you can see where i am going with this.




leon 


.


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## fast*st (Aug 12, 2007)

The Donaldson strainer is pretty cheap, just a strainer afterall. It screws
into a 3" bung and gives a 1.5 NPT out. I'll likely reduce this down to a 
proper fitting for the 1 1/4 suction line, the line from the tank to the pump 
will just be a 1 1/4 line, not a 3" 

the high pressure fittings will be 3/4 and I'll likely add a couple swivel 
fittings on the suction side, just to make service easier. 

-Jason


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