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HillsideMaple
03-03-2020, 05:49 AM
Anyone out there have a CDL 100gph Hobby RO? I I bought one to put into use this year. I noticed the other day was the top cap to the membrane housing had 2 cracks in it. The cracks are where the stainless nipple is threaded into the cap. I didn’t dare run the unit thinking high pressure concentrate would be spraying everywhere. Wasn’t sure if anyone else has noticed this issue. The CDL dealer I bought it from has a new one on the way. I’m a little hesitant to install the new part if it’s the same material will it crack again.
HillsideMaple
03-03-2020, 08:06 AM
21116
Here are pictures of the cracks. Easier to see if you zoom in.
Bricklayer
03-03-2020, 04:23 PM
That’s what happens when you thread stainless or any metal fitting into plastic, especially tapered threads. I’ve found that out the hard way many times. I’m Sure CDL should know this also.
I have my own rule of thumb now. If it’s female plastic it gets a plastic male nipple fitting then a female metal fitting. I’ve never broke a nipple this way so far.
If it’s metal female your attaching to then metal is fine.
HillsideMaple
03-04-2020, 11:25 AM
Makes sense. Thanks for the info Bricklayer
maple flats
03-04-2020, 05:01 PM
I was a plumber for about 15 years, just installing outdoor wood boilers. You will find that teflon thread tape should really not be used when turning a metal part into a plastic female thread. The teflon doesn't give you a good reading on just how tight the part is getting to. I suggest you use a teflon thread paste, and be careful not to over tighten.
With practice you can get good results using teflon tape but it requires lots of practice to be consistantly good with it.
HillsideMaple
03-10-2020, 11:19 AM
So I got the new cap from CDL. This one is the cap the put on the higher grade models. It’s solid plastic not the webbed one. Got the RO running only to find out the bottom cap was cracked and leaking. Luckily the dealer ordered 2 caps. I used the brush on thread sealant along with Teflon tape. All is good now. What a difference boiling concentrated sap! Loving it!
maple flats
03-10-2020, 07:14 PM
I would not use teflon tape, just the brush on thread paste when turning SS into plastic, solid or webbed, it is not made to hold up to the forces you get when using teflon tape. The teflon is just too slippery.
HillsideMaple
03-11-2020, 08:36 PM
I can understand why. There is a lot of pressure on the RO fittings. Better off going with the sealer.