Length of drain tube/RODI

[MichaelJ]

Like it says.. I will be relocating my ro/di... to the other side of the house, but I want to keep my drain the same.. If I move it, the tube will be about 35' ? I figure as long as it is dropped a percentage every few feet then it will work?

Any comments on this?

Michael

 

[JohnK]

I think it should be fine?

I run my output line 50-70ft and I don't have any problems with that. The only concern I can think of would be if the increased volume coming out of the waste might have a harder time moving through a long stretch of same diameter tubing?

 

[MichaelJ]

I think it should be fine?

I run my output line 50-70ft and I don't have any problems with that. The only concern I can think of would be if the increased volume coming out of the waste might have a harder time moving through a long stretch of same diameter tubing?

So what are you saying? The drain tube should be larger? If so, how can I go from the diameter it is now to a larger size? Do they have adapters?

 

[JohnK]

I'm not sure. If anything I'm saying I think it will work fine.

If you did want to use a larger diameter tube just to be safe, you can get an adaptor and larger tubing at HD for a few $.

 

[Yaktop]

theres no pressure in the line, run it as long as you want.

 

[JohnK]

That's what I thought too,

I was just wondering about frictional loss (is that the correct term?), but I doubt that it would be an issue.

An easy way to be sure, run the waste line into a 5 gal bucket and time how long it takes to fill, then attach the longer line and repeat. As long as the time / flow rate is similar your all set.

(or just don't even worry about it )

 

[MichaelJ]

If you have a section of tubing that has to go at an uphill direction for around 5'.... will that be a problem? Or will it just end up pushing the waste water out?

 

[NateHanson]

I don't think a couple feet of elevation will be any problem. However, there IS pressure in the waste line if the waste line is restricted. (as in any application, pressure isn't just a function of how hard something is being pushed, but how restricted the outlet is as well). Whether 70 feet of 1/4" OD tubing will constitute any substantial back pressure, so as to affect the performance of the RO membrane, I don't know. But if you want to be on the safe side, I'd step it up to 3/8" or 1/2" OD tubing. HD has JG type adaptors for the various sizes.

 

[MichaelJ]

Do they have a backflow preventer for those type lines?


And Thanks Nate.... and everyone else.... I think I will step it up to a bigger line just to be on the safe side...

 

[hunter57]

Typically you want pitch of 1/4" per foot for a drain.

 

[Yaktop]

However, there IS pressure in the waste line if the waste line is restricted.

duh........

 

[Gina McReeferson]

Your waste water already flows through a restrictor anyway, I doubt the 1/4" tubing will cause any problems (have you seen the inside diameter of the restrictor? ). FWIW, I run our waste water line up into our suspended ceiling (about 4' vertical) then it travels about 30' horizontally before emptying into a bathroom drain, this is all done with 1/4" flexible line and I have no problems with unit operation or production.

-Dave

 

[MichaelJ]

34' , not bad.... now I feel pretty confident about moving this now... Thanks everyone..

 

[JohnK]

There you go, Dave nailed it.

 

[Yaktop]

yes sir he did...........unless of course someone sticks a nail in the end of the tube

 

[NateHanson]

Well, by "restricted" I'm referring to the friction loss in a long length of narrow tube. The flow restrictor is certainly narrower but it's short. At some point the back pressure from the long run of narrow tubing will be greater than the back pressure from the flow restrictor, and your product ratio will be affected.

I don't know if that break-even point will be at 50 feet of 1/4" or at 500 feet of 1/4". But it'll happen at somepoint.

 

[MichaelJ]

Well, by "restricted" I'm referring to the friction loss in a long length of narrow tube. The flow restrictor is certainly narrower but it's short. At some point the back pressure from the long run of narrow tubing will be greater than the back pressure from the flow restrictor, and your product ratio will be affected.

I don't know if that break-even point will be at 50 feet of 1/4" or at 500 feet of 1/4". But it'll happen at somepoint.

So maybe at 1/2 the distance I should put a flow preventer? That's something to think about.

 

[delta]

if you are really concerned just run 3\8 tubing then there should be no problem as long as pitch the run

 

[MichaelJ]

if you are really concerned just run 3\8 tubing then there should be no problem as long as pitch the run

My biggest concern was the fact that there is going to be a spot that will go up for about 3 or 4 ft. But I don't think that will matter...