Hydraulic Pump Noise... but not always.

[RDSmith]

Update. The end plate on the six spool valve bank has SVE22 which the doc oldnslo referenced says is "SVE22 Power Beyond Outlet w/ #8 SAE Beyond Port #10 SAE ORB (7/8-14 THD"

Does power beyond imply open???

The nine spool valve has SVE21 "SVE21 Open Center Outlet w/ Conversion Plug #10 SAE ORB (7/8-14 THD)"

Now to figure out if the single valve controlling the carriage travel is open?

If all the valves turn out to be open could they be put in series somehow is the new question I have now.

 

[oldnslo]

RD,
On the SV document page V29 shows what the power beyond plug looks like. It should have a #8 SAE ORB port which is 3/4-16 threads. You would then connect this port to the next valve down stream to get your series circuit.

My concern is that from your earlier posts your valves are set up as closed center again on page V29 it states the closed center plug should be stamped CC. If your plug is stamped CC it would explain what you are seeing and confirm that at present your valve is closed center.

The good news is it should be convertible at a minimal cost and minimal effort Vs having to replace the complete valve stack.

I certainly hope what I am stating makes sense.

 

[K5lwq]

Ok from looking at the PDF Oldnslo provide and the model number you provided RD, Your valves are in fact closed center. So when spools are in everything is blocked. Below is copied from the PDF.

SVW1BA1 4-Way Double Acting w/ Spring Center (Work Ports Blocked in Neutral)

 

[oldnslo]

K5lwq,
This is a mobile valve so it has an additional flow path which is what the CC plug closes to make open center. That spool description is a little confusing since it states work ports blocked but does not mention the pressure path.

Look at the schematic on the top of page V27 it shows the open center flow path and also the CC plug at the far right of the schematic.

 

[K5lwq]

K5lwq,
This is a mobile valve so it has an additional flow path which is what the CC plug closes to make open center. That spool description is a little confusing since it states work ports blocked but does not mention the pressure path.

Look at the schematic on the top of page V27 it shows the open center flow path and also the CC plug at the far right of the schematic.

If you look at the different model number options you will see that the two choices are in neutral position blocked or neutral position open to tank. This valve was shipped closed center.

I do agree and would think it can be field converted to open center with power beyond. I doubt these have been and it would explain the problem RD is seeing.

 

[RDSmith]

I must admit this is very confusing to me right now guys.
I did look at the ends of both valves banks. Six spool "SVE22 Power Beyond Outlet w/ #8 SAE Beyond Port #10 SAE ORB (7/8-14 THD" and
The nine spool valve with SVE21 "SVE21 Open Center Outlet w/ Conversion Plug #10 SAE ORB (7/8-14 THD)" I realize I'm repeating myself.

Yes, both had plugs with the "CC"

Can I get one of the different plugs to make everything open?

Please don't get tired with/of me guys.

 

[oldnslo]

RD,
I believe that yes you could purchase a P/n 660280001 power beyond cartridge. This item is listed on page V24 under outlet cartridges.

From your description the SVE22 is the only valve that originally had the power beyond option installed. SVE21 was an open center assembly.

Now the big question is how do you want these valves plumbed together. Based on model codes the valve assembly with SVE22 was the first valve from pump and it fed valves down stream.

 

[K5lwq]

I think what was originally happening was the use of probably 2 gear pumps with closed center valves. They did this with unloading valve in the system. That is likely what the small pilot hose feeding. I will post a video that explains what I am referring to.

Oldnslo is Giving you good guidance so I will just follow along as not to add confusion. This is just for a better understanding of what you are dealing with.

 

[RDSmith]

I feel I haven't been clear enough about one thing. When I bought the mill there were two hoses hanging out the end. I assume one went to a pump(s) of some sort. And the other one went to a reservoir I'd assume. The hose from the pump branched off to all three valves (three elbows) at once... the 6 spool, the nine spool and the single valve that controls the carriage travel. (Oil doesn't go from one valve to another.) I haven't changed that.
Oh, no. After viewing the video (thank you for that k5lwq) I may have to change my mind about two pumps? I'll have to view the video a few more times maybe to understand it for sure... or closer.

But it still bother me that fluid can go to all three valves at once. Sure glad the test isn't going to be tomorrow.

I'll look into buying some of those plugs.

Still confused about SVE22 being open but with the "CC" plug thing.

I missed "Look at the schematic on the top of page V27 it shows the open center flow path and also the CC plug at the far right of the schematic." I'll look at that.

 

[oldnslo]

RD
According to the model codes those valves were originally open center and could have been one or two pumps.
Looking at what you have today I believe the valves were converted to closed center at some point in time.

a concern that I have on the mill operation is that I believe at least two of the functions must operate at the same time with a controlled flow for each function. These functions are the saw blade speed and the carriage travel speed. You may have posted which functions on operating on each valve but I do not recall.

having a pump dedicated to each function would make maintaining speed for each of these functions much easier.
Just a suggestion but if that was mine I would sit down and put together a sequence of operation or steps.

then look at these functions and determine which functions are controlled by which valve assembly. This might provide some insight on if having two pumps would make running function sequence easier and at more controlled speed since single pump flow will want to the path of least resistance and may cause some functions to operate way to fast and be hard to control especially since with a single pump you must have enough flow to run the simultaneous functions together

I hope you take this as advice on trying to help vs telling you to do.

another big unknown is how was this plumbed originally vs today??