Pressure Water Plumbing - PEX, etc.

[Zach]

I'm installing a Zurn Pex system on Noel. I like the red and blue color coding to idiot proof hot and cold water!

TAREUA, is there an easier way to cut through the ring than with a short bit of a hack saw blade? I've tried a few different side cutters, and haven't had any real success since the ring doesn't stand up high enough to get a bite.

[James S]

I think the color scheme sounds cool but wont you be insulating the hot side?
I used the tube foam and then wrapped it with 2in electrical looking tape.

[TAREUA]

The color coding is nice, but you end up with two coils of extra instead of one.
I was talking about Wirsbo removal before, with Zurnpex its a little different. They have two styles of clamps. The quick clamp, which I would recommend, you can just (this is what they tell me, I haven't done it myself) use tin snips to cut the ear that sticks up, then it can come apart. The old style copper crimp ring, which I have never sold, has a crimp ring removal tool that they sell. There is probably a trick to do it without one, but not one that I'm familiar with.

[thefilthywhore]

you have the same option of color coding (red/blue) with wirsbo aquapex.

two things to remember with zurn

1. you are using a hose clamp just like with hose, if the hose clamp comes loose (corrosion, vibration) you loose all of your water.

2. the fittings reduce the interior size of the pipe, for example- using 1/2" tubing the interior diameter of the fitting is only 3/8" whereas the wirsbo the tubing is 1/2" and the interior of the fittings are also 1/2" and you stretch the tubing out larger to fit the outside diameter of the fitting into it.

as a building inspector, wirsbo aquapex is the only system I will trust with my limited water supply. and trust me I have seen every system imaginable.

now if you are talking about a house, all of these and more are great systems, but I would still use the wirsbo aquapex given the capacity of flow, lifespan and cost.

joey

[Christian Van H]

Joey, that is an excellent point about the flow reduction of hose clamp type fittings. Also, if you read back in this thread, you will find personal experience of the clamp type stainless connections failing...more than once. I'm sold on Wirsbo, but I may use the brass fittings instead of plastic. As far as the oxygen barrier hose goes, I'll have to research whether it's only useful for protection of ferrous fittings, something that shouldn't be a problem in Webasto heating systems.

NOW, anyone find a good ONLINE distributor that sells small quantities:?

GORD, there could be a magazine article in this. Good old boat, DIY, etc.

[Christian Van H]

OK, here's a good one: PEX Plumbing - Aquapex Plumbing - PEX Plumbing Systems - PEX Plumbing Applications

They seem to have it all, and you can buy one fitting or a whole box...

[GordMay]

Originally Posted by Christian Van H

... As far as the oxygen barrier hose goes, I'll have to research whether it's only useful for protection of ferrous fittings, something that shouldn't be a problem in Webasto heating systems...

Use Wirsbo AQUAPEX tubing in hot and cold potable water distribution systems and hydronic heating applications where the system contains no ferrous
corrodible components or when ferrous components are isolated from the tubing.
For applications requiring an oxygen diffusion barrier,
use Wirsbo hePEX™ plus tubing.

Originally Posted by Christian Van H

... there could be a magazine article in this. Good old boat, DIY, etc.

I agree wholeheartedly, and encourage anyone undertaking such an installation (even a small partial re-plumb) to photo-document their work, and write it up.
I’m morally certain that publications, such as Good Old Boat (etc), would be pleased to publish an illustrated article*.
Send me a PM if you want specific advice on preparing & submitting an article for publication.

* Good Old Boat - Writers Guidelines

[s/v Jedi]

So, now that the hoses are worked out, I'm still left puzzled:

- what is the max. water temperature for both types? It seems my hot water is hotter than the stated max of AQUAPEX but I think in Celcius and get confused when reading Fahrenheit easily. Do you mix hot with cold at the heater to get the temperature down before it enters the AQUAPEX?

- How about the plastic fittings? Are they good for hot? how hot?

I'll start looking for Wirsbo here in Panama ;-)

cheers,
Nick.

[GordMay]

PEX is rated at XXX temp and XXX pressure.
For heating applications, Wirsbo PEX is rated* at
73.4̊ Fahrenheit (23̊ Celsius) at 160 psi,
180̊ F (82̊ C) at 100 psi
and 200̊ F (93̊ C) at 80 psi.
For plumbing, PEX is limited to 180̊ F (82̊ C)).
Temperature limitations are always noted on the print line of the PEX tubing.. PEX systems are tested to and can be used with standard T and P relief valves that operate at 210” F and 150 psi.

The Ontario Building Code stipulates that the maximum temperature of hot water supplied by fittings to fixtures* in a residential occupancy shall not exceed 49̊C (120̊ F).
* Does not apply to hot water supplied to installed dishwashers or clothes washers.

* Temperature ratings are issued by the Hydrostatic Design Stress Board of the Plastic Pipe Institute

[s/v Jedi]

Gord: so max. temp. is the same for AQUAPEX and hePEX and well below 212F/100C at 80 psi. Unfortunately, there's no spec for rating at 50 psi nor any spec for the plastic fittings/manifolds etc.

I guess this means that a thermo-controlled cold & hot mixing device (no idea how that's called in English, something like "thermostat valve"?) must be installed. Also, brass fitting for hot water and heating, no plastic. Now we need to know the water temperature from heaters like the Webasto diesel water heater.... it might be too hot for pex!

About the Ontario building code: that seems like a very low temperature to me.... far below safety temperature for "veterans disease" !

cheers,
Nick.

[GordMay]

In most Canadian homes, hot water heaters have been set at 60 C (140̊F). However, water at 60 C can cause third-degree burns in most adults in six seconds. Third-degree burns are the most serious kind; they damage all layers of the skin.

Hot water must be stored at a high temperature, as a precaution against bacteria*. It can be delivered from the tap at a lower temperature to prevent scalds. This is what the OBC requires.**

The solution to the temperature dilemma is to use a quality mixing valve to allow VERY hot water to go to the dish washer and laundry machines to actually kill GERMS and use these tempering valves to control the temperature of the water after these devices to go throughout the system.

Now when this hot water does reach a shower or faucet you can add safety devices called pressure/temperature regulating/valves or balancing valves etc. What these devices do is protect the user from being scalded when someone else flushes a toilet and the pressure drop is acted upon with no chance of the user being burned.

* For example, temperatures under 50 C may increase the risk of Legionnaires’ disease, a form of pneumonia, due to bacterial growth in the tank. That disease is caused by Legionella bacteria, which live in water. Temperature is a critical factor for Legionella to grow. The risk of colonization in hot water tanks is significant between 40 and 50 C. Drinking contaminated water is not a major cause of Legionnaire’s disease.

** Here’s what the Australians say:
http://www.actpla.act.gov.au/__data/.../2130/Pn18.pdf

[lookoutnw]

I used PEX & Acme Sharkbites in my water & hydronic plumbing. Have a few spare parts. But in any case on a boat, 2 million miles from anything, you should be trying to enable yourself to adapt to teh emergencies easily. A few extra feet of Pex, a few extra fittings, you should be ok. Proper Preventive maintenance checks & proceedures is teh key to keeping anything ship shape. Ease of repair is a great factor. But in all, it comes down to what YOU believe is teh best for your boat. You are ultimately responsible for EVERYTHING. Not the government or the Coast Guard. Here's to a quiet easy cruise!

[s/v Jedi]

Yes, but spare plumbing parts aren't going to help prevent Legionnaire’s disease (thanks Gord, my straight translation from Dutch wasn't far off ;-)

IIRC, the minimum water temperature in a waterheater is 70 degrees Celcius which is the temp. at which you can be sure to have killed all those bacteria. I don't think there's a maximum temp for water running to faucets.

Hydronic plumbing: what's the water temperature in there? This is a pressurized system so temp could easily go up to over 100C/212F. Are these units full-on and off or are they stepped?

We plan to go north ;-)

cheers,
Nick.

[Christian Van H]

Hey Nick on Jedi! My Webasto manual says: "The temperature limiter is a thermostat that responds (opens) at a temperature of 95° C (203° F). The
temperature limiter will automatically reset (closes) once temperature falls well below 95° C (203° F)."

So there you have it. BTW, what is your native language? Oh, and stop picking on Center Cockpits!

[James S]

My Isotemp water heater has a manual mixer on it.
Its a simple thing....the cold water supply has a tee before entering the tank, it has a flexible braided line that tees into the hot discharge side with a small valve.
This allows the water in the heater to be as hot as possible but tempered as it exits.