Spool valve

[Lea]

How can you tell which is inlet and outlet on spool valve that isn't marked?
Would the relief be on the inlet side or outlet side?

 

[Rich B1]

Inlet.

 

[Lea]

Do you mean the relief valve is always on the inlet side of the spool valve?

 

[oldnslo]

Yes, typically the relief valve will be in the inlet port of a directional control valve. On bigger fancier valves they can also have work port relief valves built in.

Can you post a couple pictures of the valve in question?

 

[Lea]

Yes I will post some pictures tomorrow

 

[Tx Jim]

Ditto on relief valve will be on inlet side.

 

[Lea]

Here are some pictures of valve body in question
For some reason I can not get pictures to upload.

 

[Lea]

Maybe some pic this time

 

[Lea]

On the second pic you notice the lever is in forward position, it only goes the one position and does not reverse and it does not return to centre. I've never seen this before and no idea what it could be used for,, any help would be appreciated
Thanks

 

[oldnslo]

Lea,
The lever only going to two positions would be a detented valve. This holds the valve in which ever position you select. Can be used for running a motor or providing flow to secondary circuit.

Looks like the first 4 sections (left to right) may also have some type of work port feature option. Could be work port reliefs or possibly work port check valves.

Is this an open center or closed center valve?

Any idea what type of machine this was designed for?

With out having the valve in front of me I would suspect that the inlet is on the left while looking at the valve from the handle side.

 

[Lea]

How do you tell if it's open centre or closed

 

[oldnslo]

If you blow air in the inlet does air freely flow out the outlet or tank port?
If yes this would be a open center used with fixed displacement pumps.
If no then it is closed center used with variable volume pumps.

 

[Lea]

Thanks for the answers oldnslo, think I got it figured out now.
Lea