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pex tubing size


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5 minutes ago, Mike Farquharson said:

was changing toilet and needed to extend the pressure line but pex line is not 1/2 ore 3/8 any ideas.

 

Thanks Mike

Here are the dimensions for Pex.6C8F4B06-633E-41ED-AAF8-BE3BD4CE5CF1.thumb.png.c3bfa7ac7af5373598fccea8207ab562.png

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I worked on a 70' houseboat made in TN that had metric pex fittings throughout, go figure. Took us 2 days to figure that out. Looked like 1/2" but was a little bit smaller and would not seal with standard sizes.

Marine plumbing places sell the metric. Hope this helps.

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22 hours ago, Mike Farquharson said:

thank you for your replys the tubing has an od of .500 and a id of .345  

 

Thanks Mike

You could get some 1/2 inch rubber heater hose and slip it over the PEX and hose clamp it.  That’s similar to what I had to do on mine although it was 5/8 PEX.  The OD of 5/8 PEX is 3/4 inch, so I slipped 3/4 inch heater hose over the PEX.  The 5/8 PEX was difficult to find unless I want to buy a 300 ft roll.  The hardware stores stock 1/2 and 3/4.  Apparently, 5/8 is used a lot in heated flooring applications.  

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There are two common kinds of PEX in use for plumbing.

There is the red/blue/white PEX-B and there is the white PEX-A (red/blue can be found but hard to find)

PEX-A is my preference because if the water inside the line freezes, it can expand to greater degree compared to PEX-B.  However, PEX-A uses different fittings and requires a more expensive expansion tool ($399) vs. the much less expensive crimp fittings used on PEX-B that works with a crimping tool ($25-$50).

       
PEX Tubing size Outside Diameter Minimum wall thickness Inside Diameter
1/4" 0.375 0.0575 0.26
3/8″ 0.500″ 0.070″ 0.360″
1/2″ 0.625″ 0.070″ 0.485″
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6 hours ago, 6Wheels said:

There are two common kinds of PEX in use for plumbing.

There is the red/blue/white PEX-B and there is the white PEX-A (red/blue can be found but hard to find)

PEX-A is my preference because if the water inside the line freezes, it can expand to greater degree compared to PEX-B.  However, PEX-A uses different fittings and requires a more expensive expansion tool ($399) vs. the much less expensive crimp fittings used on PEX-B that works with a crimping tool ($25-$50).

       
PEX Tubing size Outside Diameter Minimum wall thickness Inside Diameter
1/4" 0.375 0.0575 0.26
3/8″ 0.500″ 0.070″ 0.360″
1/2″ 0.625″ 0.070″ 0.485″

Can shark bite fittings be used on all pex types?

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Sharkbite fittings will work on PEX-B not PEX-A.

In a mobility environment I would not advise these fittings due to the vibration they would experience.  I would not put them behind a wall either.

The best fittings would be the crimped ring, but the clamps are good as well.  None of these will last forever.

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This post has been very informative.  I did some research and found that there is another type of PEX - Type C, used in radiant flooring, and it has a higher chlorine tolerance.  
I also discovered that PEX has a max temperature rating off 180F. On my coach, there are several feet of heater hose coming out of the engine water pump.  Then there is a fitting that transitions to PEX that runs all the way up front to the heater core and then another fitting to change back to rubber heater hose.  The return line is just the opposite.  A few years ago mine separated at the fitting and there was not enough slack to make a repair, so I removed the fitting, slipped 3/4 inch heater hose over the 5/8 PEX and then installed a 3/4-5/8 barb fitting and connected it to the water pump hose. 
Now I’m wondering why Monaco used PEX when it’s max temperature rating is 180F.  The engine water temp is much higher than that.  Looking at the specs for PEX, the max temperature does increase with lower pressure, but it stops at 180F.  I don’t know if all DP’s are configured this way, or whether my coach is “special “, since it was made by Navistar.
 

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