Log Splitter Hydraulic Filter, Gauge Questions

[LanceH]

Hi there everyone. Hope everyone is safe and sound tonight. The lovely Ohio weather has me cooped up inside due to a tornado warning and funnel cloud spottings. Anyway, I've built the frame of my new log splitter and am in the process of 'ebaying' a Haldex Barnes 11GPM 2 stage pump. My questions are as follows:
1. Is it better to put a filiter on the suction side or return side?
2. What size inlet/outlet ports?
3. Should i buy an 'in tank' suction line strainer?
4. Is it a good idea to put a pressure gauge in the system?
5. If so, where?

Northern Tools website and my local Tractor Supply has filters on the return line. But I thought you wanted to protect the system before the dirt went thru. I was thinking of putting my 'in tank' strainer on the suction side, and the filter head on the return side.

Any pictures or detailed explanations are much appreciated.

I'll now try to add 3 pictures of my progress.

FYI-Anyone trying to bolt a pump mount onto a 5.5HP Honda GX160 engine should go to their local hardware store and buy 4 (four) M8 bolts that are one inch long. I dont know how the metric system works, but my Ace hardware had them in up in the bins. They were $0.09 cents each and 45 cents sure beats buying the 'kit' from Northern Tool for $4.00.

 

[PILOON]

Tank screen is a good idea.
Placing the tank pickup (suction to pump) above the bottom of the tank also good idea as that way the pump suction cannot ingest sediment.
Filter would go on low pressure or suction (between pump and tank).
A 'breather' on tank with filtering to keep out bugs etc also good idea.

An inline filter on pressure side is rare and not pratical due to the high pressures.

Good luck!

 

[JoelD]

Filter on the low pressure side prior to pump, on my backhoe I mounted it right off of the tank. Definately need breather on tank.

I ran 3/4 to the pump from the tank, 1/2 should work for all other.

I had a strainer in the tank where which the outlet hose then fitted into.

I ran a guage on my old back hoe, I mounted right off of the valve body, trying to remeber where exactly, I think there was a fitting on the valve body.

You could always T fit it on the hose going out of the valve body to the piston, you'll get pressure reading there.

Looks good,
Joel

 

[6sunset6]

I think you can put a strainer on the suction side but I think the filters have to be on the tank return from the valve.. I think filters will have too much restriction for the suction side. Unless the whole system is specifically designed for that.

 

[LanceH]

Thanks. That did some clearing up. I incorrectly assumed the suction side was the high pressure. Wouldn't the return line that comes from the valve to the tank be low pressure, just like the suction side from the tank to the hyd pump? Sorry, I'm obviously new to hydraulic systems like this.

 

[shutt40]

1. Is it better to put a filiter on the suction side or return side?
2. What size inlet/outlet ports?
3. Should i buy an 'in tank' suction line strainer?
4. Is it a good idea to put a pressure gauge in the system?
5. If so, where?

1. You can put the filter on the return or suction side. The reason you see them on the return is because you can use a smaller filter housing on the return than on the suction side. They are normally rated for both with the suction rating being about 1/3 the return rating.
2. At 11 GPM 3/4" or 1" would be fine for tank ports, but you will need to go bigger to add the suction strainer.
3. I would if you are going with a return filter, if you use a suction filter then no need.
4. Unless you are going to adjust the pressure relief on you valve a gauge is just a nice to look at kinda thing.
5.You can install it with a tee on the pressure line from pump to valve. It will only show pressure when the cyl is doing work.
Hope some of that helps.
Frank

 

[shutt40]

And yes both the suction and return are low pressure
Also nice work on the splitter, gota build me one, one of these days
Frank

 

[LanceH]

Frank,
thanks for the valuable info. I appreciate your input.

-Lance

 

[LanceH]

And yes both the suction and return are low pressure
Also nice work on the splitter, gota build me one, one of these days
Frank

Frank-I've finished that splitter up and am now starting on a new, diesel powered splitter. I'm still thinking about putting a gauge in the system and it sounds like it can be on the cylinder line coming in from the pump or on the line from the valve to the back end of the cylinder. My question is related to the definition of "LOW PRESSURE"...if low pressure on the supply side is between the tank and pump, then where does it transition from high pressure to low on the return side? When it leaves the valve body or somewhere around the return line filter?

I just want to know where I need to run my 'return line hose' which is slightly larger diameter than the remaining 3/4" high pressure lines.

Also specs on new splitter:
10hp china clone diesel engine
5x24x2.25 cylinder
prince valve w/3/4" ports (all 4)
16gpm 2 stage pump

Thanks again.

 

[J_J]

Your gage should go in a tee at the P/input to the valve.

 

[Mace Canute]

Putting a filter in the suction line runs the high risk of cavitating the pump (cavitation is very damaging). There are a few rare exceptions to this but in general you should install the filter on the return line to the tank. An 'in tank' suction line strainer is not needed either. Make sure the tank is clean first and then make sure you don't drop any crap into it at any times afterwards. If you want a strainer, get one that sits in the fill hole. Much more practical.

 

[AKKAMAAN]

My question is related to the definition of "LOW PRESSURE"...if low pressure on the supply side is between the tank and pump, then where does it transition from high pressure to low on the return side? When it leaves the valve body or somewhere around the return line filter?

The transition between high and low pressure is actually inside the control valve, but count the tank port on the control valve is the transition point. 150psi is "high pressure" in a return line (basically in the filter)....all of it created by resistance in return filter, hose and fittings.
Make sure get a return filter with a flow by pass valve, pressure setting usually around 15-50 psi....

 

[AKKAMAAN]

If you want a strainer, get one that sits in the fill hole. Much more practical.

+1 :thumbsup:

 

[J_J]

Over engineering, and I know what the charts say. I really don't understand the need to go larger that the pump inlet and outlet and valve inlet and outlet size. I could see increasing the size on a long run, but on about 6 ft of hose. Common sense would dictate they match the ports, plus the increased cost of larger fittings and hoses has to be taken into account. I think I would make all the hose the same, 3/4 in except for the 1 in suction hose.

 

[AKKAMAAN]

Over engineering, and I know what the charts say. I really don't understand the need to go larger that the pump inlet and outlet and valve inlet and outlet size. I could see increasing the size on a long run, but on about 6 ft of hose. Common sense would dictate they match the ports, plus the increased cost of larger fittings and hoses has to be taken into account. I think I would make all the hose the same, 3/4 in except for the 1 in suction hose.

It is possible to cut some corners when designing a system, if you know the "risks"....
On the pressure side of a fixed displacement pump, undersizing will create pressure drop during flow (no flow no pressure drop), but entire flow will still get to destination, if some of the flow is not partially diverted.

Pressure drop is a POTENTIAL source of TO MUCH HEAT. TO MUCH, depends on, cooling capacity, and cycle frequency.
So I agree that there can be some unnecessary "over engineering".

Cost of lost energy and cooling vs cost of larger sized hoses, have to be calculated.
In some low frequency cycled system we can cut the corner with some "common sense", if we KNOW we have that common sense.

One should always try to design for as much laminar flow as possible
Smaller size fittings and hoses, increases fluid velocity.
When fluid velocity increases, the turbulence increases (Reynolds number is at 2300 or higher)
Turbulent flow increase resistance and pressure
Slowing down velocity in a larger hose between to smaller sized ports, will reduce pressure loss, PERIOD!
Do we need that reduction of pressure loss?? Thats another question....On a suction line, definitely YES!


The suction side is different, because there is a limited pressure to drive the fluid through the suction line, the 14.7psi atmospheric pressure.


Homework 1: This addition of total restriction on the suction side, is a little bigger when extending a DA cylinder than when retracting the same. Why is that??

Homework 2: Why would it make sense to have a larger sized line between the control valve port and the capped side port of a DA cylinder??

 

[LanceH]

Thanks JJ. I'll put a tee on the inbound side of the valve body.

This is the type I was going to go with: Valley Instrument 2 1/2in. Stainless Steel Glycerin Gauge — 0-3000 PSI | Filled Gauges | Northern Tool + Equipment

The picture must just be a stock image. It is a 0-3000 psi gauge and its glycerin filled which I read should be better suited for my log splitter application-which has lots of vibration.

Is 3000 psi too big or not enough? I chose this because my pump max output is 3000 psi and I didnt think the system pressure would be larger than this.

 

[ptexer]

I think Mace Canute statement was very well written and accurate. Akkamaan did another great post. I would just like to say I believe strainers in tank or filters on suction side have the potential for more damage than benefit.

 

[LanceH]

Thanks JJ. I'll put a tee on the inbound side of the valve body.

This is the type I was going to go with: Valley Instrument 2 1/2in. Stainless Steel Glycerin Gauge 0-3000 PSI | Filled Gauges | Northern Tool + Equipment

The picture must just be a stock image. It is a 0-3000 psi gauge and its glycerin filled which I read should be better suited for my log splitter application-which has lots of vibration.

Is 3000 psi too big or not enough? I chose this because my pump max output is 3000 psi and I didnt think the system pressure would be larger than this.

About the max pressure that the gauge will read...I'm wondering if my barnes 16gpm pump will ever be able to create anything over 3000 psi? I just want to know if a gauge that reads a max pressure of 3000psi is good or if i need to get the next one up which is 5000psi.

Any advice?

 

[J_J]

You may see pressure spikes above 3000 psi, but most people use the 3000 psi gage.

16 GPM two stage pump.

3000 PSI max
4000 RPM max
First stage 16 GPM @ 650 PSI
Second stage 4 GPM @ 2500 PSI
16 GPM @ 3600 RPM