why to not use a float valve on ro/di in sump

[Lavoisier]

Just trying to understand:

Originally Posted by Wazzel

Float valves work just fine. If you use one you just need to take the precautions appropriate for float valves.

No matter if you use a float valve or switch, never attach directly to an RO/DI unit as your top off. Short cycling the filter is bad for the filter. Having an infinite water supply hooked to something that might fail open if risky.

They work just fine but they fail?! I am not tracking with your logic here. No one recommended to the OP to attach directly to an RO/DI unit as your top off. Just the opposite...

Originally Posted by Wazzel

I have used float valves as my tank topoff before. I still used them to shut my RO/DI off when making water. I work under the notion that any piece of kit will fail at some point in time and take appropriate precautions. Someone said you can never have to many checks. That is actually not true. You can over safe yourself into problems. The trick is to have the correct checks.

Sorry, but I've never heard an engineer disparage redundancy. Please explain how failsafes "over safe yourself into problems" specifically in terms of this thread.

Originally Posted by Wazzel

I never said they do not fail. Go back and read what I wrote. I plan my systems assuming that every piece of kit will fail and plan around dealing with that.

My laundry room has a floor drain. If my bucket float fails the floor drain will deal with it and I will have little to clean up.

Floor drains are a good thing (I have one myself). Is this one of the ways you handle a failure?

Originally Posted by Wazzel

Well sometimes it is not about adding in redundancies but planning to handle a failure. If I was to use a float valve on my current tank the top off containers would be 10 gallon and never full. My sump has about a 8 gallon cushion and my tank evaporates 5 gal a week. So the failure would be delt with. Like with my water bucket a failure would be a low impact event.

So you are not currently using a float valve!? How are you doing your top off?

Originally Posted by Wazzel

Understanding your system and failure modes. Sometime the best way to deal with one thing is just making sure the system can handle it, not adding additional equipment. That back up equipment can fail also.

I am an engineer and design interesting tooling for a living. Often we deal with failure potential by making sure it can be contained, not by adding additional kit since it is not always possible or practical. I take a similar approach with my tank.

I prefer to avoid a failure if possible and then contain a failure if my redundancies proved inadequate. Why would you not try to set up a system with failsafes? I guess this is the point where you lose me.

Originally Posted by Wazzel

My point is adding equipment is not always the best solution. Total system planning is a much better approach. I have given two examples already.

The equipment I have added is a result of "total system planning." You may be creating a straw man argument as I have not read anything in this thread that suggests haphazardly adding equipment solves anything. I am a teacher and do not have the resources to throw $$ away. By the way, I must have missed your second example.

[Wazzel]

Originally Posted by Lavoisier

Just trying to understand:



They work just fine but they fail?! I am not tracking with your logic here. No one recommended to the OP to attach directly to an RO/DI unit as your top off. Just the opposite...



Sorry, but I've never heard an engineer disparage redundancy. Please explain how failsafes "over safe yourself into problems" specifically in terms of this thread.



Floor drains are a good thing (I have one myself). Is this one of the ways you handle a failure?



So you are not currently using a float valve!? How are you doing your top off?



I prefer to avoid a failure if possible and then contain a failure if my redundancies proved inadequate. Why would you not try to set up a system with failsafes? I guess this is the point where you lose me.



The equipment I have added is a result of "total system planning." You may be creating a straw man argument as I have not read anything in this thread that suggests haphazardly adding equipment solves anything. I am a teacher and do not have the resources to throw $$ away. By the way, I must have missed your second example.

Not sure what you are missing. Setting up a system to fail safe and adding redundancy is not the same thing. I set my stuff up to fail in a safe manner if it were to fail and only add redundancy if absolutely necessary. It is not an uncommon design condition to not have redundancy but built in safe failure points. Think about all the non-redundant systems in you car.

Sorry if I am not being clear enough, but I am not interested in continuing what looks like it is going to be a real nitpicky conversation.

[Lavoisier]

Wazzel, I've enjoyed our exchange but I think you are right in that we seem to be talking by each other. I hope we can find another issue to share ideas...

In any event I hope the OP has found his thread helpful...sorry if we drifted.

[johnike]

I'm sending you two to the Lounge for an hour.

[Lavoisier]

Originally Posted by johnike

I'm sending you two to the Lounge for an hour.

Thanks, John, I think we need it...I just wish we could share an electronic beer or two.

[johnike]

[Wazzel]

Originally Posted by Lavoisier

Wazzel, I've enjoyed our exchange but I think you are right in that we seem to be talking by each other. I hope we can find another issue to share ideas...

In any event I hope the OP has found his thread helpful...sorry if we drifted.

It happens. I like to bow out before things get nasty. No offense ment.

[Wazzel]

Originally Posted by johnike

I'm sending you two to the Lounge for an hour.

You buying? I like Caribbean rum, Angostura 1919 in particular, on the rocks or with diet coke.

[Wazzel]

Originally Posted by Lavoisier

Thanks, John, I think we need it...I just wish we could share an electronic beer or two.

Water based are better.

[johnike]

Tact and diplomacy win again.

[natereinhold1]

Actually you guys didnt drift tooo much. I do understand what wazzel is saying about the difference in redundancies and failsafes. Redundancies: you have another piece of equipment to fix the problem if another fails (ie. Float sticks so you have a float switch cut power to the pump if water gets two high, now their is 2 pieces of equipment to potentially fail)
Failsafe: your ato res is only 5 gallon on a 200 gallon system, if the pump stays on who cares (other than you have to fix it)
Thats the difference that he is speaking of, total system design. He is an engineer and I know how they think, I work on much more complicated machinery and mechanical processes than what we deal with in reefing ( ie. 15 ton presses that hammer away 18" strokes 6x a second, the forces generated here are insane) and we have 0 redundancies built in, the entire factory had been built using the fail safe method (much safer when dealing with the wellness of humans). If it is going to fail, and it will, just make sure that when it fails, the outcome of the failure happens in a controlled manner that was planned out ahead to not impact the system as a whole.

[natereinhold1]

Overall both ideas achieve the same thing... safety in a complexe, multi-part system. And as with most things, moderation between the two is best as there are some things that just cannot fail safe and some stuff cannot be redundantified (I made up a new word!)

[natereinhold1]

Thanks all for the input and hopefully if anything we gave a few that are new to the hobby a better idea of things to keep in mind while designing their new system and maybe save a few tanks along the way

[Lavoisier]

Originally Posted by Wazzel

It happens. I like to bow out before things get nasty. No offense ment.

None taken...I'd love to buy you a water based brew or a Caribbean rum, Angostura 1919 in particular, if I I ever get to LA...Happy New Year.

[Wazzel]

Originally Posted by Lavoisier

None taken...I'd love to buy you a water based brew or a Caribbean rum, Angostura 1919 in particular, if I I ever get to LA...Happy New Year.

Your on, I'll get the second round.

[johnike]

I love this place.



Happy New Years guys!!