Flexible PVC not suitable for drinking water -- why do we use it in our tanks?

[tonyespinoza]

So I'm considering flexible PVC for my tank plumbing.

The site says it's not suitable for potable water applications because it leaves a "plasticky" taste in the water.

From a chemistry perspective, why would this be the case? Is there some residue being combined with the water in the pipes? Is this considered inert to our reef systems or has no one really looked into it?

 

[hoxbar]

I'm a plumber and the reason we do not use "flexible" pvc is because it will not hold pressures associated with potable water systems. If you wanted to use a flexible type of plastic pipe I'd suggest PEX. Pex stands for Cross-linked polyethylene. Pex usually takes special tools and fittings but this piping is the best thing on the market!

 

[tonyespinoza]

awesome - it's great to have an expert's opinion. if you happen to know a good place to order the PEX parts and tools online, lemme know.

am i correct in assuming the PEX stuff will work schedule 40 fittings?

thanks again hoxbar.

 

[tonyespinoza]

would i use PEX with hose barb fittings to use my schedule 80 gate valves?

all the PEX fittings i'm running across online are ... brass, which i assume we don't want to use with our tanks...

 

[bertoni]

Flexible PVC works well enough for many tank applications. Can you describe your plumbing in a bit of detail?

 

[tonyespinoza]

I'm using the beananimal/herbie drain approach. Three 1.5" drains (one full siphon, one open channel, one emergency) that feed my sump. Two of those drains require gate valves. From the intake portion of the sump I am feeding a BK 300 Deluxe External skimmer via Eheim 1262. A second 1262 (post filter socks) acts as the return to the tank with a valve/bleed drain feeding my fuges.

I think I'll also have a small dedicated pump that feeds my carbon reactor which feeds my Geotronic chiller/heater from the "clean" area of the sump post filter-socks. (I assume this will be vinyl tubing.)

Pretty simple. But the system is in my living room and I want to do everything possible to make it fool proof and avoid leaks.

Thanks for any guidance! And if you know anyone in the Bay Area that's a whiz and would like to help me out for a few extra bucks, lemme know.

 

[bertoni]

If none of the runs are very long, the flexible tubing would be fine. If the sump is in the basement, I wouldn't use it. I would replace the vinyl every year.

I'm not sure whether PVC would be more reliable or not. I'd likely stick to the flexible tubing.

 

[tonyespinoza]

Thanks bertoni -- Just to be clear - are you saying go with clear vinyl tubing (even for the 1.5" drains) instead of PVC and replace it annually? or are you saying, go with flexible PVC?

 

[bertoni]

I'd go with the one that looks tougher. They should both be reasonably easier to handle.

 

[therealfatman]

PEX tubing can be used with Guest fittings up to 1" tubing. It is fairly stiff tubing and is difficult to install over barbed fittings. It has barbed fitting specifically designed for its use but most require special crimping tools be used with them.

Guest fittings and PEX tubing are the typical tubing and fittings used on RODI systems. The tubing comes in four differnt colors but it degrades when under long term exsposure to UV light.

By codes flex PVC is not even considered tubing but is instead considered hose. It should not be used for long vertical runs or any high pressure applications where the water is not flowing. It should not be used in any system that has fast operating solenoids.

 

[stugray]

tonyespinoza,

Go ahead and use the flex-pvc from HD.

I used three runs of 1" from my display to my basement ( about 10' each ).
Two are for drains & one for return.
Put in unions at each end & use the red "hot" glue ( also at HD ).

Stu

 

[tonyespinoza]

hey stugray - (love your signature)

my sump is really close to my display (3 feet?) so i think it will be safe.

so why use red "hot" glue instead of normal PVC cement??

or something like this:
http://www.gorillapvc.com/

 

[OwenInAZ]

I helped my father-in-law plumb up his 90 a while ago, and we used flexible PVC without problems. Used the quick-setting two part cement. There aren't any runs of over three or four feet, and nothing is very high pressure (1" off of an external pump for the return)

 

[therealfatman]

Unless you want to hunt down the fittings with larger solvent contact areas for solvent welding your pipe the differing solvents will make very little difference. The problem lies in the minimal solvent welding areas not the solvents. Other than that the problem lies in the pipe itself not the solvents.

The only difference in solvent welding PVC pipe and PVC flex hose is with the pipe you should twist either it or the fitting after apply the solvent and inserting the pipe into the fitting. With the PVC flex hose you do not twist.

Unless your talking many feet of static head or standing water head flex PVC is fine. Like said by others in other threads I would not use flex PVC hose to run from a basement when using a high pressure pump and any quick acting solenoids. That would be about the only limitation I would consider. I would not worry about using a multi floor flex PVC drain system that was free flowing. I would not however be snapping the ball valve quickly closed at the bottom end of a multi floor flex PVC drain hose.

It is merely less of a risk if using rigid PVC pipe for the longer straight parts of vertical runs and using the flex PVC hose in smaller sections that are more difficult to run straight rigid pipes through. Flex PVC hose at the top of large vertical runs is safer than at the bottom of the run.

The PEX tubing is safe when used vertically. Below is a link to a site with 1" and smaller fittings that can be used with PEX tubing. No solvent welding even required. PEX is sold at HD. One inch is used typically for radiant floor heating and some larger main water lines.

Pretty simple.

http://www.rosystems.com/mm5/mercha...e=John-Guest&gclid=CJbE6M-6gZgCFRIcawodSm3nDA