Mobile logsplitter

[farmboy3]

Hi,just finished building a mobile log splitter similar to the Uniforest bmf,but not sure what size pipes to put on it,1/2 or 3/4 . The pump is a 16 gpm ,does it make any difference to the speed of the ram operation? Any advice would be much appreciated

[Stubby]

I would go the larger with 16GPM . If it dosn't flow readily it could stall the engine over heat the fluid and or destroy the coupling .

[waterbuoy]

Agree with Stubby. You can't really have hydraulic pipes that are too large (within reason) - big pipes keep friction etc down and pressure up. Exactly the same with domestic fresh water plumbing - shower etc. larger bore pipes deliver greater pressure to the shower head due to reduced losses.

[openspaceman]

Agree with Stubby. You can't really have hydraulic pipes that are too large (within reason) - big pipes keep friction etc down and pressure up. Exactly the same with domestic fresh water plumbing - shower etc. larger bore pipes deliver greater pressure to the shower head due to reduced losses.

 

You are right but at the limit bigger bore pipes withstand less pressure than smaller, so check the working pressure of the pipe.

[Stock]

Hang on a tick there, what is the size on the ram? and what size is your spool valve? putting 5/8 hoses on a spool rated for 3/8 is a waste.

here is a sizing chart and the recommended flow rates

 

A 1/2" hose will carry min 12 gal and a max of 19 g/min

 

Hydraulic Reference Page - Mac's Hydraulic

[Stubby]

Hang on a tick there, what is the size on the ram? and what size is your spool valve? putting 5/8 hoses on a spool rated for 3/8 is a waste.

here is a sizing chart and the recommended flow rates

 

A 1/2" hose will carry min 12 gal and a max of 19 g/min

 

Hydraulic Reference Page - Mac's Hydraulic

 

Also ....How big is the oil tank . With 16GPM you need at least 3 times the flow rate in capacity or it will over heat . So 48 galls minimum .

[cornish wood burner]

Depends on the length of your pipes and oil viscosity. If for 1/2 say you have a pressure loss of 1.5 psi per ft then assuming a 10 ft length you will lose 15 psi or so. Remember to add the return length also. If you are happy with that then 1/2 will be cheaper and easier to handle. Pressure drop on a 3/4 pipe is a lot less with less heating of the oil.

[waterbuoy]

You are right but at the limit bigger bore pipes withstand less pressure than smaller, so check the working pressure of the pipe.

 

I did say 'within reason'!!

[farmboy3]

The inlet/ outlet ports on the spool valve are 3/4 but the two ports for the ram feed are 1/2 also the two feeds on the ram are 3/8 ,even if I went with 3/4 pipes wouldn't these restrict the flow entering the ram?

[openspaceman]

The inlet/ outlet ports on the spool valve are 3/4 but the two ports for the ram feed are 1/2 also the two feeds on the ram are 3/8 ,even if I went with 3/4 pipes wouldn't these restrict the flow entering the ram?

 

It's normal to have a bigger hose to the spool and then smaller outlets from the spool to the services, also a still bigger return hose to tank. This is to reduce internal friction as the flow is constantly running through the valve block but intermittently going to the service ports., Return to tank is larger to prevent pressure build up in valve block.

 

My point about working pressure is because typically a 3/4" 2 wire hose has a working pressure of about 1500psi and agricultural kit tends to have relief valves set at about 2000psi.