PEX Advice

[Bexar]

Good advise and experience shared. Appreciate everyone’s input!!

[SailorSam205]

Originally Posted by Isuzusweet

Had to do it a few times and found no problem?

Cheers
Tony

I agree. I made some changes to my plumbing. It was pretty easy to break the existing crimp fittings with a largish angle cutter and open it up. Pipe slid off the existing fittings with only moderate effort. Based on recommendations I found on the web, I did cut off the sections of pipe that held the fittings before installing my new stuff - about 1/2 inch.

[AlinCal]

Originally Posted by SailorSam205

I agree. I made some changes to my plumbing. It was pretty easy to break the existing crimp fittings with a largish angle cutter and open it up. Pipe slid off the existing fittings with only moderate effort. Based on recommendations I found on the web, I did cut off the sections of pipe that held the fittings before installing my new stuff - about 1/2 inch.

Aquapex ProPex fittings are not crimp, they use a tool that expands the pipe and ring and DO NOT easily come apart , the use of heat to soften the pipe after the ring has been removed is nesessary.

Shark Bite brand PEX (and similar) pipe and fitting DO easily come apart once you cut the ring or crimp off.

That said the only reason I can see were you might want too would be to reuse the fitting, the pipe would still need to be cut back on ether type to get a fresh pipe end.

The grey pipe on end of autofill solenoid is what my trailer had originaly afaik. It is NOT PEX pipe

[GM Airstream]

wow... interesting that you are doing what I just went through... with mine... I had the gray tubing.. and its known for failing... with the plastic fittings... and it started as a little drip from one of the (you can't find 'em anymore) drain valves... so we got in their and replace 'em with new ball brass valves...

We got the blue, red and white PEX tubing made by sharkbite... along with the brass connectors... and used the copper rings and compression tools... elected to go with the sharkbite tool at first but it came apart so we went with the apollo brand... but, found that it was hard to get the tool into places... even when you make up the tubing replacement before... so we ordered the 45 deg angle tool... from the big box store.. and that seemed to get into tight places easier... I did try one of the rigid 45 angle tools from a friend and like it.. but the price was higher...

I went with the copper compression rings at the advise of our neighbor a plumber... they seem to last and do a good job of easy assembly... (you use a gauge tool to make sure they are within specs on each fitting)

I found that sharkbite makes just about anything needed in the 1/2 inch.. ballvalves, adapters etc... and went with their products due to being made in the USA...

Its not cheap.. and the PEX tubing is thicker wall... which makes it different from the orginal PB tubing... so you can't use the PB fitting.. and sharkbite make a adapter that will work from PEX to PB tubing if you splice it in... that one has the copper ring on the PB side...while the PEX uses the black copper on its side.. you can see the difference in the rings... as the bright copper is used to take up the difference.

I was advised not to use the push on fittings...from sharkbite and others... as they only have a O ring that seals the tubing... and it will eventually start to leak with age.. making you have to go in and do it all over again... The PEX compression fittings are in use and have been for over 35 years... so they seem to work well...

The stainless steel clamps... are what the RV industry is currently using.. but my plub'er neighbor said that they are narrower and while they do work.. are not as good for higher pressure...as well as they have a tendency to cut the PEX tubing if not put on exactly right... and are move expensive than the copper compression rings...used on the PEX... and to cut one off.. is not as easy... however they are cheaper tooling... and one tool works for all...

Another tool that I got was the apollo ring cutter... this way if you make a mistake.. you can cut the compression ring off... and re-use the brass fitting again...

About the only other thing I found was that AS used 3/8 tubing on the hot water side..from the input point to the kitchen... and I am sure the reason they did that was to use less water...as it comes out to be about half the displacement in the tubing... in gallons of water... so you would get hot water much faster and not waist as much waiting for it to get their... etc... I used 1/2 inch red PEX.. as that was all the big box store had... but, I did find adapters from 1/2 PEX to 3/8 PEX... only thing is the big box store doesn't carry 3/8 PEX tubing.. pooo...

To pull in the new PEX lines.. I found that crimping on a adapter fitting from the PB tubing to PEX and attaching the PEX line... you could pull the old line and it then pulls through the new... with ease... simple Remember that the code says that the red stuff is for hot and should be on top... blue, cold on bottom... etc.. but in RVs doesn't matter...

If I had any advise... I would say.. get a good 45 deg Compression too... not a cheap one... and keep it for more projects... A good PEX tubing cutter and the apollo compression ring cutter tool... Dont go with plastic ...or push on fittings... use brass ... and you will also have to lay things out in direct lines.. and 90 deg brass fittings... as the PEX tubing doesn't like to bend in tight radi... Try to make up the assembly before getting into the tight spot in the trailer... and use the copper compression rings from sharkbite... for the PEX tubing... (they are cheaper and seem to work better) Follow the directions of putting on the rings and PEX fittings... on UTUBE... and you should be golden...

someone said why didn't you use copper tubing... which has it problems... and is very expensive these days.. let alone the end fittings... ouch...

After I got done learning the navy new language directed towards the engineers at AS...I found it was not that hard to re-plumb the trailer... once you have the tools and hardware needed...

PROBLEMS WITH PEX....

seems its made from the same stuff wire insulation is... and little 4 legged critters love to chew on it... then again they also liked the old gray PB stuff too.. so make sure you take protection against them and leaks...
...some said that its got a taste to it.. but , we found that flushing the line like anything else.. took care of the problem...

..no worry about freezing.. its better than anything else.. and even if it does freeze... the tubing is able to take it... the fittings being brass or plastic.. won't...take the abuse...

The new AS are using the household PEX tubing... that has been used for the last 35 years in houses and in EU...

Good luck... stay away from the older gray PB stuff.. it is known to be a problem...

[AlinCal]

^Good Advice...

The only thing I will add is to use pipe insulation on both hot and cold lines, it will do the obvious job and it will help protect from rubbing or chaffing wear as well as make the system quieter keeping it from vibrating against the trailer when the pump is running.

[rmkrum]

also avoid exposing PEX to UV light, like direct sunshine. It tends to deteriorate...if you run a drain line, wrap it in black split loom or pipe insulation...

[Bexar]

Looking over the pex system I’ve extracted from this old timer it used brass connectors & copper rings. It also has a whitish goo applied to all connections which appears to my untrained eye to be the liquid equivalent of teflon tape. What was this stuff? No mention so far in this thread. This install is moderately old but it did not leak. I just did not like the layout and am updating it along with other infrastructure.

[GM Airstream]

Originally Posted by Bexar

Looking over the pex system I’ve extracted from this old timer it used brass connectors & copper rings. It also has a whitish goo applied to all connections which appears to my untrained eye to be the liquid equivalent of teflon tape. What was this stuff? No mention so far in this thread. This install is moderately old but it did not leak. I just did not like the layout and am updating it along with other infrastructure.

Indeed.. I have seen others put teflon tape around the fittings before crimping on the new rings... this is really not a good thiing.. as the crimp down is to get the tubing to form around the lands on the fittings... all connections should be made dry.. I was told... if you put tape on them they won't seal right... even though they appear not to at first... the will not allow the edge of the brass land to press into the tubing... making the seal...and thus not make a good connection...

Also.. for those who have said.. ops guess I didn't make a good connection ..yet the GO/NO GO gauge seem to be correct... but the fitting could turn inside the tubing... not to worry... if you made the connection correctly and use the compression rings in the right place... it is only the land of the fitting turning inside the tube... that has formed around the land and will still do a good job of sealing... for a long time...

But, I wouldn't make it a habit of twisting the fittings.. just to be on the safe side.. but we all seem to miss the right angle every so often.. and tweek the fitting around to make 'er work...

All good stuff... and making experts out of the many A/S owners and mechanics...

Used to hate PEX.. now I find I like it much better than even copper tubing... and while the tubing is REAL cheap... fittings.. well... brass is expensive but never the less.. you need 'em to make the system good for life...

[perryg114]

Not long ago I was able to use a sharkbite slip on connector with three different types of tubing. There was copper on one side coming from the outdoor supply line, PEX going to the low point drain for the fresh water and the original gray PB tubing. I used the stiffeners for PEX that came with the sharkbite and wrapped a little Teflon tape around them and inserted one in the PB tubing. The PB outside diameter is 1/2" or close enough anyway. The inside diameter is a little bigger than PEX. I don't recommend this as a permanent solution but it worked for me. I think the slip connectors are ok in places where you can see them and check for leaks. I am gradually replacing the plumbing in my trailer but I need to remove belly skins to get to the main supply line. The only thing that has failed with the PB stuff is the plastic fittings.

Perry