Valve education?

[J_J]

On the one J_J refers too , YES, on the one I show, NO, and they are two different Prince valves....I noticed this "discrepancy" a while ago.....no biggie....but a little disturbing....because it is inconsistant....I think that it is, sort of, common custom in valve industry, to have B port plugged, if it is a Way valve for a single acting cylinder....


WOOOPPS my bad...to tired.....sorry....A port of course plugged on my picture too...

In the PDF above, Prince says if using the valve as a three way, to plug A port and connect cyl to B

The reason for the question, was that in using a double acting valve with a SA cyl, I would think the valve ports would have same characteristics, and therefore, either port could be plugged, depending on the way you wanted the lever to operate the cyl.

I will call Prince Mon to find out for sure.

dcyrilc,

I think you have to plug the other port in case someone inadvertently shifts the lever the wrong way.

 

[AKKAMAAN]

Can you give some explaination of the meaning of the different parts of the schematic you gave in this post. What does the symbot on the left edge mean, and what does each section from left to right mean, and lastly what is the symbol on the right?

are you referring to the whole picture or just the "symbol" on the right side??


On the left side of the picture you can see part of the spring assembly that make sure spool goes to neutral when you take your hand off the control lever.....I will make it easy for you now....helping you refer to parts of the picture.....

 

[EE_Bota]

J_J...I read the thread, and everyone posting knows more than I, since my experience is in factory stuff, where there is no handle for a operator to grasp.

But I do wonder if the recommendation about which port to plug and which port to use has something to do with operator comfort. I have operated valves on some tractors that tend to "grab." By "grab" I mean that instead of resisting operator inputs to the handle with steady spring tension, under load a reaction force in the spool tends to make the spool pull in the direction that operator is pushing, therefore "grabbing." View this as food for thought, not so much as knowledgeable input.

I have seen spool setups that "grab" and I have seen spool setups with detents that overcome the detent under load and pop back to neutral.

I have often wondered if this was at the root of some of the jumpy 3ph reports on TBN.

 

[AKKAMAAN]

In the PDF above, Prince says if using the valve as a three way, to plug A port and connect cyl to B

The reason for the question, was that in using a double acting valve with a SA cyl, I would think the valve ports would have same characteristics, and therefore, either port could be plugged, depending on the way you wanted the lever to operate the cyl.

I will call Prince Mon to find out for sure.

dcyrilc,

I think you have to plug the other port in case someone inadvertently shifts the lever the wrong way.

Thank you for your post i_J

.....Good luck calling Prince....please give heads up about their way to handle your call....

I think Prince is the best manufacturer available for good info and spec sheets....But I think they draw some stuff little of the standard way to draw sometimes.....just small details like the plugged A port instead of B port, some minor details on symbolic drawings etc...

But over all, I think Prince information is outstanding for what regular people can access....

 

[Barry Bowen]

Do not buy an open center and put in the plug to make it closed center. It just does not work all that well. You will have a small high pressure leak constantly. Closed center valves are machined to a tighter tolerance, or at least they are supposed to be. I did the open center and pluged on my JD 301A and the valve got to hot to touch inside of an hour. I went and got the closed center valve that was that way from the factory and it has been fine ever since, 4 years now.

Other mistake, I should have bought the closed center with float and detent on both spools. I will regret not getting that until I finally have enough extra cash to go get that kind of valve. I figure probably 400 or so.

 

[dcyrilc]

Do not buy an open center and put in the plug to make it closed center. It just does not work all that well. You will have a small high pressure leak constantly. Closed center valves are machined to a tighter tolerance, or at least they are supposed to be. I did the open center and pluged on my JD 301A and the valve got to hot to touch inside of an hour. I went and got the closed center valve that was that way from the factory and it has been fine ever since, 4 years now.

Other mistake, I should have bought the closed center with float and detent on both spools. I will regret not getting that until I finally have enough extra cash to go get that kind of valve. I figure probably 400 or so.

Hi Barry,
Nice to hear from you. Good information to know for those of us with Closed Center systems. I almost always buy things designed for what I'm going to do with them. IE: Closed Center valve for Closed Center system. Curiosity here, why do you want the float feature for the dump?

 

[dcyrilc]

In the PDF above, Prince says if using the valve as a three way, to plug A port and connect cyl to B

The reason for the question, was that in using a double acting valve with a SA cyl, I would think the valve ports would have same characteristics, and therefore, either port could be plugged, depending on the way you wanted the lever to operate the cyl.

I will call Prince Mon to find out for sure.

dcyrilc,

I think you have to plug the other port in case someone inadvertently shifts the lever the wrong way.

Hi J_J,
I'm interested in hearing what Prince has to say. I would think that on a standard spring return to center DA valve it wouldn't mater which port was used. However, if using a single direction motor spool, one of the ports may not be blocked in neutral and therefore would not hold the cylinder in place when the valve is in neutral if the wrong port were used. Either way, the unused port needs to be plugged (either with a plug or with a QD) so that fluid is not lost through the open port when valve is pushed the other direction to retract the cylinder.
I could be way off base too, and it could just be generic terminology to indicate that the unused port has to be plugged. I'm lookig forward to hearing what you find out.

 

[dcyrilc]

FarmerFord did a excellent job of describing series vs. parallel valves in post #7 of THIS thread. Also the link provided by Shaley is great also. The short story is though for loader and backhoe valves parallel is preferred because you are often doing more than one function at a time. You would not need that for your remote valve so save the money and go with the series.

Hi Kenny,
I haven't read your link yet, that's next. As the two valves I referenced were preassembled single spool stack valves, it didn't put it together that there were both series and parallel valves. As soon as I read the word parallel in your post, it clicked and started making sense.

Thanks for your response. It's funny how just one word can help things make sense sometimes. OK, time to go read FarmerFord's thread.

 

[dcyrilc]

This was an interesting note at the end of Prince's PDF. http://www.tractorbynet.com/forums/...hoe-valve-questions-pages-prince-valvessv.pdf

CLOSED CENTER APPLICATIONS
The SV Series Circuit Valve sections cannot be used in
a closed center valve assembly

 

[dcyrilc]

Here is catalog page 14 from Surplus Center's catalog. https://www.surpluscenter.com/pages/014.pdf

I'm assuming here that Standard Spool Types A - F must be Parallel?
And Optional Spool Types J - N must be Series?