Greetings all -

Have run into a snafu plumbing in the Velox. Used John guest type push-in fittings and tubing to run the water supply line to the machine. These were sourced locally, so inch sized. The tubing is 3/8", ending with a shutoff valve. Picked up a water pressure regulator and gauge that has integrated 8mm push-in fittings.

So now I need a reducing junction to go from 3/8" to 8mm. So far this has proven to be unobtainium. I've tried Granger, McMaster-Carr, Amazon, ebay, and a general search. If available, an 8mm to 1/4" adaptor would also work and I could then go from 1/4" to 3/8".

Hopefully someone out there may be able to point me in the right direction. Thanks in advance for any assistance.

Not exactly understanding what you're looking for... maybe some kind of compression fitting for copper tubing, male, female? What kind of fitting is it integrating to, male, female? Who makes this water pressure regulator/gauge? What does it's fitting look like? Can you post some photos of what you have and also something similar to what you're looking for?

Have you tried ChrisCoffee or Espressoparts.com? They both deal with John Guest fittings...

https://www.chriscoffee.com/collections ... est?page=1
https://www.espressoparts.com/search/?q=John+Guest


Unfortunately, like you, the only place I know of that has unobtanium is Pandora!

Fresh Water Systems has both 8 mm and 5/16" (7.9375 mm) John Guest. It's possible that a stem-style fitting or changing out a cartridge in a union could help. They or a John Guest catalog might be able to confirm.

Edit: Reading the FWS descriptions, 8 mm and 5/16" may be compatible. See, as one example, https://www.freshwatersystems.com/produ ... stem-x-3-8

Thanks for the replies.

nahau- It is a push-in plastic system, John Guest being the most recognized. Unfortunately when I ordered the regulator I didn't realize that once again I would be butting my head against the lack of metric support here. Here's a quick pic of the regulator and a kludge I came up with. The regulator fittings are for 8mm tubing and I found some 5/16 vinyl tubing that works, just. Then jammed that into the 3/8" for the hose fitting and taped it with waterproof tape. It works, but would rather come up with a more elegant solution.

I'll check that site to see if they have it in 8mm.

jeff - I did check out FWS, but think I'll contact them directly to see what they come up with. After going over page after page on site after site, it's all starting to blur together. I purchased everything else I needed from Stafano, but they didn't have that final piece. I need to go from 8mm at the regulator to 3/8" at the hose fitting.

David thanks for the purchase,
now that I can see a picture I can think about it a little more clearly,
basically you are looking for something to go out from the wtaer regulator and that size is a JG 1/4 line and not a 3/8 like the fitting you got from us?
if so why not a piece of 1/4 line and then attach the JG reducer (or increaser) I should call it?

Hi Stefano -

Thanks for dropping by. I took the regulator with me to a hardware store with a good selection of bulk tubing. The 1/4" didn't fit well enough to make a seal, so just tried different sizes to find one that would, with the 5/16" vinyl being the closest. Unfortunately it is too large to fit in the 1/4" end of the reducer connectors(3/8 > 1/4) I had purchased. An 8mm to either 1/4" or 3/8" connector would be the ideal solution.

The enlarger fitting that Jeff linked to is a good idea if I can find one to fit the 5/16 vinyl tubing and FWS does not list one.

We have a similar one but is like so


then second thinking
copper tubing???

Might have found another possibility on FWS. They have a barbed strait connector that would get me 5/16" poly tubing on one side and 3/8" poly on the other.
https://www.freshwatersystems.com/produ ... 0288484395
https://www.freshwatersystems.com/produ ... 9779728427
https://www.freshwatersystems.com/produ ... 9511981099

My main concerns are that there's no max pressure spec'd for the fitting, and whether the 5/16" poly tubing will seal as well as the vinyl in the regulator. The cost is low, so may just toss the dice.

If the hose is 8mm OD, then is the hose ID = 6mm? Or is the hose ID 8mm? This is for air, but could it be used for your application being such a short run?

https://www.overstock.com/Home-Garden/R ... Male&rfmt=

Generic search...
https://www.overstock.com/Reusable-Fitt ... ype=Header

Also, there are barbed adapters on McmasterCarr that would probably work like the first link in your last post. Although I don't know the hose ID.

https://www.mcmaster.com/hose-adapters/ ... -water-10/

The closest to 8mm tubing I could find was 5/16" O.D. It measures about 5mm I.D. and 7.5mm O.D. The 5/16 is too big to fit the 1/4 spec'd push-fit connector, so 8mm wouldn't work on that end.

Stefano - Didn't think to try using copper tubing with the push-fit and not sure how well it would seal. When removing the vinyl tubing from the push fitting there is a slight ridge from the fitting seals. I probably have some 8mm copper, so will check it out.