T port valve connection

[smeagol77]

Hello,
i am working on a project, a hydraulic crawler wheelbarrow, and I have the following question.
I would like to point out that this is the first time i am working with hydraulic systems.
I have connected two P40 distributors in series through the N port and the question is if it is ok to connect the T ports as seen in the attached photos?

 

[smeagol77]

A few more pictures

 

[ptsg]

Yes, no worries on connecting the Tank ports that way. However, did you use the proper PB sleeve on the first valve? Or just a regular fitting?

 

[smeagol77]

thanks for the reply.
i didn't use this PB sleeve, just a regular one (no leaks at the moment)
Can you please tell me what the difference is?

 

[smeagol77]

Here it is

 

[smeagol77]

I studied the problem and I think I understand why you need the proper PB sleeve
practically separate, internally, the N port from the T port
correct?

 

[ptsg]

I studied the problem and I think I understand why you need the proper PB sleeve
practically separate, internally, the N port from the T port
correct?

Yes thats it. Otherwise the fluid will bypass to the tank port and won't feed the second valve.

 

[oldnslo]

I can’t tell by the pictures. Do you have one pump feeding both valves or two pumps one feeding each valve?

If a single pump you need to run pressure from pump to 1st valve. Then power beyond of 1st valve to pressure port of 2nd valve.

Then Tank of both valves to tank. They can be connected like you have them now.

Looks like ptsg types faster

 

[old and tired]

Looks like you are filtering the return to tank... that's ok but normally you want to filter the oil before the pump (to protected it from "junk" floating in the tank/oil).

You'll most likely (accidentally) contaminate a system via. the tank (filling or topping off). Filtering before the pump also protects the valves (spools) from contamination (they are more susceptible to failure due to foreign matter).

 

[smeagol77]

I had a filter on the suction but it was quite small and together with a 1/2 inch I.D hose there wasn't enough oil reaching the pump

I think I'll modify the tank and install this filter on the suction with a bigger hose (1 inch)

thanks for the suggestions

 

[smeagol77]

Can I use only one filter on the suction?

 

[oldnslo]

You can run filters in parallel but they usually on higher flow systems NOTE: Their are specific filters designed for suction use and not all filters will work in suction application.

For a simple gear pump you can use a suction strainer that is made from wire mesh.

 

[ptsg]

On my homemade backhoe, I only run a suction strainer for the pumps and a filter on the return of both pumps.

Whatever dirt or trash that may enter the system during connecting/disconnects quick connects, stay trapped in the filter and doesn't even reach the tank.

The tank has very little risk of contamination in my opinion, as long as precautions have been taken when filling said tank.