Prince Stack Valve Relief Question

[Cocre]

Where is Sandy Run? My folks are from the Dillon area.

Sandy Run is about 15 miles south of Columbia. I will PM you about some kin in the Dillon area.

 

[AKKAMAAN]

There is absolutely no reason that the tractor's main relief (set at 2500psi) will not adequately protect the new valve and the hydraulic top link. Set the new control valve's relief above that of the tractor's main relief valve setting. There would be no harm in using a control valve with no relief at all in this application.

Agree 100%!!

 

[Cocre]

There is absolutely no reason that the tractor's main relief (set at 2500psi) will not adequately protect the new valve and the hydraulic top link.

The Prince literature does say that a relief valve downstream of the main system relief valve is optional. Not in those exact words, but that is what it means to me. They also say if you have one it can't be set higher than the upstream relief, only lower. I think what they mean by this is that setting it higher will not actually effect a higher relief pressure on the system because the upstream valve will lift before the higher pressure of the downstream valve is reached.

I have ordered a gauge and will do some messing once it comes in.

Talking hydraulics is just about like talking politics and religion.

 

[RickB]

RickB ,

Perhaps this will help. It mentions something about the relief valve settings.

Whether the next valve in-line has a relief or not, it will see the main system pressure, and when you activate one of the cylinders, the cyl will see main sys pressure. If it has a relief valve, it should be set at same or lower.

Naah, it didn't help at all.

Prince is telling us that the second relief can't be set above the main setting. Reason being, the system will default to the lower original or main relief setting. Fine, I understand that. Prince is also telling us the second RV is optional. If it is set higher than the main relief, it's as if it wasn't there. Great, we don't need it at all, I say.

Now let's consider the practical application that drove the original post. What you haven't explained is why new components which are rated for installation on systems with a 3000PSI working pressure need to be protected by a secondary relief valve set below the main RV setting of 2500PSI. The only possible result of setting the second RV as you suggest is diminished performance of the new toplink cylinder due to unnessarily low operating pressure. The second RV is totally redundant because all components in the new circuit can handle the 2500PSI main relief setting. Lecturing theory is fine, just make sure the theories fit the practical application that drives the questions. In this case, yours don't.

 

[AKKAMAAN]

I think what they mean by this is that setting it higher will not actually effect a higher relief pressure on the system because the upstream valve will lift before the higher pressure of the downstream valve is reached.

I think you got that right!!

 

[RickB]

The Prince literature does say that a relief valve downstream of the main system relief valve is optional. Not in those exact words, but that is what it means to me. They also say if you have one it can't be set higher than the upstream relief, only lower. I think what they mean by this is that setting it higher will not actually effect a higher relief pressure on the system because the upstream valve will lift before the higher pressure of the downstream valve is reached.

That is precisely what I mean. Thanks.

 

[J_J]

Rick

You are assuming that all add on system will be able to handle the main system pressure, if they can, great, and if not, what then. Some times it works, and sometimes it don't

 

[RickB]

Rick

You are assuming that all add on system will be able to handle the main system pressure, if they can, great, and if not, what then. Some times it works, and sometimes it don't

I'm not assuming anything. The OP listed the pressure ratings for the components he plans to add. There is some benefit to reading the thread before posting.