difference in double selector contorl valves.

[russG]

Hi, I'm looking at two control values. One can handle a higher flow rate(which is cheaper then the other). Can anyone explaint what the main difference between them? I want to add a second remote for rear tilt. I thought the bigher (flow) the better.

Thanks
Russ

 

[Henro]

Russ,

The way I look at it is that all you really need is a valve rated for the flow your systems has.

Everything else being equal, chances are the a valve with a higher GPM flow will also have larger physical size. I suppose in theory, the higher GPM rated valve would provide a little less resistance to flow, and would be better in that regard.

But the size of the valve for many of us would be a major negative. Unless you have a lot of space to spare, you will probably be happier with a physically smaller control valve that is rated to handle your system flow.

When it is all over, using a smaller, but capable valve, may even give the opportunity to have additional control sections in the same foot print as the larger valve would have. So if you have the space for the larger valve, the smaller one may still be better. Does not hurt to have extra remotes for things in addition to top and tilt... /forums/images/graemlins/smile.gif

 

[MadReferee]

Your TC24 has an implement hydraulic flow of just under 4 gpm (3.8 I think). You should find an external valve that is no greater than 5 gpm. This will give you full flow when the spools are in neutral and will give you the smallest footprint.

Anything bigger physically or flow wise will be overkill and not improve or hinder performance one bit. For your small tractor, I would think physical size would be the most important factor when choosing a valve.

Take a look at the Eaton-Cessna 5 gpm valves that are available thru Surplus Center. They have the smallest footprint I could find and I believe they are made in USA.

 

[russG]

Thanks for the input.
The two valves(electric) that i was looking at(surplus Center) was the SAE 8 15 GPM @ 149 or the SAE 6 8 GPM @ 189. The sizes are close to each other and since there is no stick I think i wont have a problem mouting it.

Thanks

 

[MadReferee]

Either one should work for your application. The increased flow capacity of the cheaper valve will get you nowhere as your pump can only do less than 4 gpm anyway.

The advantage of the one for $189 (#9-1782) is that it can be stacked with others whereas the one for $149 (#9-5117) can't be stacked. I assume those are the ones you are looking at.

The SAE 8 work ports are bigger than the SAE 6 (3/4 - 16 vs 9/16 - 18). Surplus Center also sells reducer bushings to get to the more common NPT threads. You would probably want to go with 1/4 NPT fittings and hoses for better control (usually no need for a restrictor) or 3/8 NPT for standard stuff.

 

[v8dave]

</font><font color="blue" class="small">( Either one should work for your application. The increased flow capacity of the cheaper valve will get you nowhere as your pump can only do less than 4 gpm anyway.

The advantage of the one for $189 (#9-1782) is that it can be stacked with others whereas the one for $149 (#9-5117) can't be stacked. I assume those are the ones you are looking at.

The SAE 8 work ports are bigger than the SAE 6 (3/4 - 16 vs 9/16 - 18). Surplus Center also sells reducer bushings to get to the more common NPT threads. You would probably want to go with 1/4 NPT fittings and hoses for better control (usually no need for a restrictor) or 3/8 NPT for standard stuff.
)</font>

Mad, you are the go to guy for hydraulic questions. So, I'd like to ask you about the ability to feather the valves in operation. Is it reasonable to expect a smaller valve to be able to have better fine tuning control than a larger valve? Like when you need to lift the implement only an inch while operating?

 

[MadReferee]

The actual valve has little if any to do with it. It is actually the amount of fluid going to the cylinder thru the work ports and how long it takes to get there.

In as simple language as I can get, you restrict the work port line by either using smaller diameter hoses or by placing a small restrictor in the lines. The smaller the restriction the longer it takes for the cylinder to fill and move. Thus the ability to hold the spool lever on and see the cylinder move slower.