Water (system) line question

[chrisncate]

Is the double walled reinforced stuff required, or can I get away with using the standard clear vinyl water tubing that is single ply and somewhat thin walled?

My lines will not be open to risk of puncture for the most part, due to how/where they can be run, so would there be any other concerns? One is $1.18 a foot, the other is 36c a foot, and I am trying $$ to save where I can.

?

(it's a pressure system)

[Minnewaska]

As I've had the reinforced stuff dry and split, I would not put less sturdy in the boat, unless I had no concern for pumping my fresh water overboard. That's happened too and is why shutting the pressure system off when underway is on my departure checklist.

[john1066]

Series 150 clear hose is OK for pressure systems. I have two concerns with it, however: Hot water softens it, and it can collapse when used on the suction side of the system.
So, on the pressure side of a cold water system it's fine.

[ffiill]

Important you source a commercial pipe stockist for your pipes if possible. Certainly over here in UK their prices are way below what you pay from a yachting supplies/chandlry.
Also certainly over here strangely enough food grade reinforced is cheaper than non reinforced.

[JonEisberg]

I'd favor going with double-walled, reinforced hose... Single-walled will want to collapse or crimp at any sharper bends, you may wind up having to make up the difference anyway with the use of elbow fittings, etc... Any place where you do have a tight bend, or subject to crushing by shifting gear or abrasion, might be worth to run such hose inside a flexible electrical conduit...

If you do, however, go with an opaque hose, rather than clear... This will help reduce the growth of algae inside your hose, which is dependent upon UV to thrive... My understanding is that clear hose, even when run through spaces we think of as being dark, will still permit such growth to a surprisingly greater degree...

[RichH]

The most important characteristic for any hose used on a potable water system is: "NDF or FDA approved for use in potable water systems". That will ensure that you wont be drinking polymer fragments (unbounded monomers) and other harmful 'leachables'. Youll have a hard time finding hosing suitable for use with potable water systems in a boat chandlery.

Unarmored clear PVC hose will change dimensions when subjected to pressure or force. Most polymers are subject to 'creep' - a constant change of dimensions due to force applied, although low pressures are OK (10-15 psi). This vulnerability change of dimensions will cause even the area under hose clamps to quickly deform .... and you will probably need to constantly retighten the clamps to stop leaks.

Armored PVC hose will also creep but at a much lower rate due to the nylon, etc. armoring internal to the extrusion, will withstand the accelerated 'creep' better with hot water; the upper limit is about 160 deg. F.

Algae requires sunlight for photosynthesis. Once PVC hosing becomes
'colored' it denotes oxidation/hydrolysis (weakening) or that the 'filamentous' portions of fungals (mildews, molds, etc.) have penetrated INTO the polymer and are using the polymer as its nutrient source. The most common contamination of a water system is bacteria and they will also discolor and penetrate the 'plastic' when using the polymer as its nutrient source. The ONLY way to prevent growth of microorganisms is to continually 'dose' the water with a teeny amount of chlorine (clorox) to about .5 - 1 parts per million (about 4 oz. clorox per 100 gallons of water) .... so that your nose 'just barely' can detect the chlorine.

Summary: Use the armored, it more stable (vs. creep) in a pressurized system and 'sometimes' it can be found to be RATED for use in POTABLE water systems.

[tommays]

In useing a lot of FDA approved hose at work

At this point with so many PEX fittings and PEX hose so cheep and easy to get i cant yet see a down side to it on a boat

[jrd22]

This might be an option for you Chris, I haven't used it but it sounds/looks good. Fittings are kind of pricey though.

http://www.defender.com/product.jsp?path=-1|51|106370|315127&id=1244499

[RichH]

jrd22 -- YUP!!!! Polyethylene is probably the BEST but the problem is that most other hardware components in such a system will have 'hose barb' connectors .... and that make all the 'terminal connections' a royal PITA.

BTW 'hose barb' connectors are probably the chief 'breeding/incubation' sites for bacteria, etc. in a water system as sanitization chemicals cant 'penetrate' the slip-on portion but bacteria, etc. 'can'.

[chrisncate]

Originally Posted by jrd22

This might be an option for you Chris, I haven't used it but it sounds/looks good. Fittings are kind of pricey though.

http://www.defender.com/product.jsp?path=-1|51|106370|315127&id=1244499

Great info all around, thank you everyone! Very helpful posts all around. I won't be going with the thin stuff.

jrd: Neat stuff, price is good also. I need to count my fittings to see how many I'd need. Either way, thanks again everyone.