3-way valves...Break before Make??

[dtfeld]

For those who use 3-way valves, can you confirm they "break before make"?

In other words they seal off the side liquid is flowing from before allowing the liquid from the other inlet to flow?

I'd like to confirm before I spend $$$ on several of them for an upgrade project.

 

[ajdelange]

All the ones I've seen are ball valves with a T shaped channel in the ball which sits in a T valve body. You turn the ball so that the flat of the T is pointed at the inlet you want off. Note that if the flat of the ball T is pointed towards the flat of the body T all three channels are connected. If you make a couple of sketches you will quickly see that you can interconnect all three arms or any pair or turn the valve off completely. You will also see that you need to pay some attention to the direction in which you move the handle when switching. In my experience just moving the valve handle fast enough that any undesired interport connections on the way to the one you want works. I find it helpful to orient the handle so that it is aligned with the stem of the ball T. This way I can visualize the ball's channel just by looking at the handle.

 

[dtfeld]

Yup...there are T port and L port. I think I am going with L ports, as I want to will have 2 inlets and one outlet to choose a source.

The immediate applications is getting rid of several T's with valves attached on my pump outlets and one on the inlet of an autosparge.

The 3 way one the pump outlet selects either a re-circulation port, or moving the liquid to the next pot.

The autosparge inlet would either let in HLT/Sparge water, or re-circulation from the Mashtun pump.

 

[Bobby_M]

There will be momentary overlap between ports when turning. In other words, there is no dead "off" position at the 45. This is why they can't be used for flow regulation.

 

[ajdelange]

With a T channel you can close off one port, with an L two. I'd consider that off and while they may not be the ideal way to control flow I use mine to do that all the time because all I want is crude flow control.

 

[augiedoggy]

They work well with pwm for pump flow control I use 4 three way valves in my setup.

 

[dtfeld]

Thanks for the feedback gents. I ordered 5 so I hope they work like I expect.

Otherwise, look for some in the for sale forum!!

Dtfeld

 

[BitterSweetBrews]

There will be momentary overlap between ports when turning. In other words, there is no dead "off" position at the 45. This is why they can't be used for flow regulation.

I use two way valves on my pump or vessel outputs to control flow control. But, I have 6 - 3 way valves and while I don't think there is a dead off, they can be used for flow control, as long as you are turning them in the right direction. I have never really looked at them to see if there was a direction, at a 45, that would shut off all 3 ports. I agree with Bobby_M, I don't think there is. I will check later as I have an extra 3 way I am not using right now.

One other thing with 3 ways is that the flow is reduced due to the necessity for a smaller channel for the "T". I don't know if it is bigger with "L" style ones but I would still get "T" style instead of "L" style. The extra versatility is a big plus.

 

[schematix]

I use all standard ball valves on my rig. If i need a "3-way" configuration i just use 2 ball valves.

 

[ajdelange]

I have never really looked at them to see if there was a direction, at a 45, that would shut off all 3 ports.

Draw a circle. Now draw a T in the circle with the intersection of the horizontal and vertical lines at the center of the circle. Now draw lines parallel to the cross bar and vertical but at some distance from them to represent the radius of the bore. I think you will convince yourself that the septum between channels is pretty narrow for a valve with channels of reasonable dimension. Or you can look into the port of a three way valve as you turn the handle. you will see that at 45 ° you can see into two legs of the ball's T. As I said in my earlier post with a T you can shut off one port. With an L, 2.

 

[BitterSweetBrews]

I checked my spare 3-way valve and it does not have a total off for all three ports. There is always an overlap with at least 2 channels open, regardless of the way it is turned. You can only turn off one port at a time, at least two are always open, even if only a little.

 

[Bobby_M]

Yes, the L does have an OFF position where nothing will flow anywhere. However, the way I read the question was whether there was an off between positions and the answer there is a definite no. The only way to truly understand these is to play with one in real life or make a scale drawing and cut out the circle for the ball and rotate that against the drawing.

 

[augiedoggy]

I use two way valves on my pump or vessel outputs to control flow control. But, I have 6 - 3 way valves and while I don't think there is a dead off, they can be used for flow control, as long as you are turning them in the right direction. I have never really looked at them to see if there was a direction, at a 45, that would shut off all 3 ports. I agree with Bobby_M, I don't think there is. I will check later as I have an extra 3 way I am not using right now.

One other thing with 3 ways is that the flow is reduced due to the necessity for a smaller channel for the "T". I don't know if it is bigger with "L" style ones but I would still get "T" style instead of "L" style. The extra versatility is a big plus.

there is no way to close all openings of the ball but as long as flow is only coming from one direction you close that port. leaving the flow to be open through the other 2...

 

[ajdelange]

With the L channel you can close off two ports. With the T configuration only one.