15mm Pex Fresh Water T fitting source

We are installing a Seagull IV X-1B Basic Drinking Water Purifier under the sink and I have to Tee into the cold water blue Fresh Water systems 15mm hose.

Has anybody had to do this and is there a particular Tee fitting that was ordered that worked good?

Is there a special tool that is needed?

The 15mm size is pretty limited source-wise. That's what I have on my boat. Google "John Guest fittings". Cheapest and most reliable source I have found is freshwatersystems.com. No special tools needed. Just make sure to buy the c-clip collar holders.

Looks like for me to tap into this hose I need a Sea-Tech 15mm to a 3/8 hose Tee?

Is there such a thing?

jefndeb said:

Looks like for me to tap into this hose I need a Sea-Tech 15mm to a 3/8 hose Tee?

Is there such a thing?

Click to expand...

Google the John Guest 15mm fittings. There are lots of different converters/adapters - you might have to jump in two steps.

I used an ice maker tap on my cousins Amal Super Maramu but that was a copper line. Not sure if it would work on the plastic supply line.

Rob

A quick Google search says no to an ice maker saddle.

How about installing a tee then this 15mm to 1/2" adapter https://www.amazon.com/Pipework-Sys...7bfc6&pd_rd_wg=WFqLy&pd_rd_i=B00YI8I59I&psc=1

it's just a few standard fittings from there.

Rob

Whale makes 15mm fittings.

This is from a few years ago, but gives you an idea. I've gotten them at Fisheries Supply.

The Mainships use the 15mm Sea Tech fittings. Here is a good source for them.

https://www.suremarineservice.com/Hardware/15mm-Sea-Tech-Fittings-Tubing/

we did this exact installation on our pdq powercat. whale makes fittings for 15mm which is what we used. defender carries them.

john
gem 2003 p34


https://www.defender.com/search.html?q=whale quick connect plumbing

Thanks, did you use the supplies 3/8 hoses or did you have to modify something?

we used their hoses, etc. we used their faucet as our drinking water source. only hard part was getting right angle to screw on to bottom of faucet.

we've had this setup for 17 years. if i were to do it again i think i'd inline right after system water pump. filter has capacity and then you've got drinkable water at every tap.

john
GEM 2003 p34

Freshwatersystems.com carries all of the fittings you will ever need for 15MM "pex" both from sea tech (now watts aqualock) and John Guess.


I'd use a fitting like this, and put a 1/2" fully threaded male tailpiece in it.


https://www.freshwatersystems.com/p...wivel-female-tee-15mm-x-15mm-x-1-2-nps-branch


They may make a t with a 1/2" male fitting built into it, I'm not sure. But the one above will work and the tailpieces are easy to find at WM or probably the hardware store.

Dougcole said:

... both from sea tech (now watts aqualock).

Click to expand...

Ahh, thank you for mentioning this. I was going to add "Seatech" above (in addition to Whale), but then couldn't remember which company they had merged with. Watts!

(I could have looked it up but was apparently feeling lazy.)

jefndeb said:

We are installing a Seagull IV X-1B Basic Drinking Water Purifier under the sink and I have to Tee into the cold water blue Fresh Water systems 15mm hose.

Has anybody had to do this and is there a particular Tee fitting that was ordered that worked good?

Is there a special tool that is needed?

Click to expand...

You need this https://www.marineoutfitters.ca/ind...0692|11370&product=60963518&code=840213133573
Then This with a short piece of 15MM pipe
https://www.marineoutfitters.ca/ind...0692|11370&product=60963512&code=840213133467

jefndeb,

attached is a pic of our installation. as dougcole said, i used the screw on tee. hope this helps.

john
GEM 2003 P34

Thank for the info....

Can you explain how you connected these two fittings you referenced?

And wouldn't I need this adapter brass to connect the 3/8 hose to it?

Much simpler to use this one:


https://www.freshwatersystems.com/p...wivel-female-tee-15mm-x-15mm-x-1-2-nps-branch


You can screw the nipple directly into it, then attach the female fitting from you filter to the nipple. Less connections than using the fittings in your above post.


I just installed an under sink water filter in our 400, though not one as nice as the seagull. The biggest challenge is that there is not a lot of room for the stiff pex style hose to flex, which puts strain on the connectors and can cause them to leak. Go with as few connections as possible.


I ended up using plain old fashioned barbed tailpieces, hose clamps and about 2' of regular fresh water hose from the outlet of my fliter up to the faucet because it is so much more flexible than the pex. It looks to me like you won't have to do that though, as the seagull comes with a flexible hose from its outlet side.

Yes, thanks but the hoses for the Seagull are 3/8, (female) so thats why I was looking at the 1/2 to 3/8 adapter...am I misunderstanding?

jefndeb said:

Yes, thanks but the hoses for the Seagull are 3/8, (female) so thats why I was looking at the 1/2 to 3/8 adapter...am I misunderstanding?

Click to expand...

Yep so you put a piece of 15mm pipe between T and 1/2" adapter then your reducer attaches to 1/2" adapter

jefndeb said:

Yes, thanks but the hoses for the Seagull are 3/8, (female) so thats why I was looking at the 1/2 to 3/8 adapter...am I misunderstanding?

Click to expand...

Last comment I had the seagull on a couple of boats Cartridges are proprietary and very expensive I switched to a Rain fresh from Loews, Cartridges are $10.00 and works as well if not better than seagull. also has an adapter that pins the tubing and clamps to the pipe. great system, and easy to bypass when winterizing

jefndeb said:

Yes, thanks but the hoses for the Seagull are 3/8, (female) so thats why I was looking at the 1/2 to 3/8 adapter...am I misunderstanding?

Click to expand...

Screw the adapter directly into the threaded outlet of the "T" that I linked for you and then screw the Seagull's hose directly to the 3/8" nipple of the adapter. There is no need for a piece of tubing in between them.


I think maybe you didn't click the link I posted? It is for a T with one threaded outlet and two pex style connections. It would be easier to use in your application than a T with three pex connections.


The setup Cartouche suggests will certainly work as well, it's just more complex and has more connections.

Oh ok, thanks, do I need any "O" rings with this Tee fitting?

jefndeb said:

Oh ok, thanks, do I need any "O" rings with this Tee fitting?

Click to expand...

You shouldn't. I used teflon plumber's tape.

Note - I believe the female threaded fittings (both straight or T types shown) seal against a rubber cone washer not thread to thread as a conventional tapered pipe thread. These fittings have straight not tapered pipe threads (NPS not NPT) and don't required Teflon tape or pipe dope. Also caution to not over tighten or you may split the outer male threaded portion.

FromWatts Catalog
"AquaLock connectors utlize a swivel nut with
NPS straight threads and a cone seal. This
allows the installer to thread onto NPT, NPS,
BSP, and most other threads without tools or
thread sealant. Simply thread on, hand tight,
for a zero-leak seal."

Cone washer part # 161-08CP
https://www.watts.com/products/plum...ic-accessories/cone-seal-35161/watts_81902634

Bacchus said:

Note - I believe the female threaded fittings (both straight or T types shown) seal against a rubber cone washer not thread to thread as a conventional tapered pipe thread. These fittings have straight not tapered pipe threads (NPS not NPT) and don't required Teflon tape or pipe dope. Also caution to not over tighten or you may split the outer male threaded portion.

FromWatts Catalog
"AquaLock connectors utlize a swivel nut with
NPS straight threads and a cone seal. This
allows the installer to thread onto NPT, NPS,
BSP, and most other threads without tools or
thread sealant. Simply thread on, hand tight,
for a zero-leak seal."

Cone washer part # 161-08CP
https://www.watts.com/products/plum...ic-accessories/cone-seal-35161/watts_81902634

Click to expand...

Yep, Bacchus is correct, sorry for the brain slip on my part. I used teflon tape on the traditional threaded fittings I used from the outlet of my filter to the faucet. I didn't use it with the aqualock fittings. You might need it for the fitting between the nipple and the female fitting on the filter though.

OK, thank to you all for your input....

I got the parts needed to install the water filter but while me messing with the blue water lines, (looking for a place to mount the filter canister) some of the connections at the manifold started leaking!!!!..

I didnt really move them around that much...Sometimes I just wanna give up....

I found that these hoses seem to just pull right out...is that normal?

This round part came out and had broken tabs on it. My guess is that this part is supposed to "grab" and hold the hose end to keep it snug to an O- ring?

It also looks like these things we not really made to be removed.

And to top it all off, they are all sold out at Freshwater systems and they seem to be the only supplier.

Aarrrrrrgggggg!!!

One problem i had early on was not pushing the tube in far enough.

There is a resistance point that makes you think you have seated it home. This is not the case - keep pushing - another 1/4" or so PAST the o-ring. Then you can move it all you want - it won't leak.

You have to push the collar back in towards the fitting (along with the tube slightly) to release the gripper mechanism.

EDIT: This was with the 15mm John Guest fittings, BTW - not sure if the mechanism is the same with what you have.

boathealer said:

One problem i had early on was not pushing the tube in far enough.

There is a resistance point that makes you think you have seated it home. This is not the case - keep pushing - another 1/4" or so PAST the o-ring. Then you can move it all you want - it won't leak.

You have to push the collar back in towards the fitting (along with the tube slightly) to release the gripper mechanism.

EDIT: This was with the 15mm John Guest fittings, BTW - not sure if the mechanism is the same with what you have.

Click to expand...

Yes it is you have to keep pushing passed when you think it is locked and then put on the safety collar to stop accidental movement

Yes, thanks to all for the help. Now I understand how these work.

However does anybody know why Mainship removed all the Horseshoe type collars for all the connections?

All of the fittings at the manifold have no collars on them, at least on my Mainship 40.

They probably are not necessary normally, like in a house but boats move around and vibrate a lot so I would think leaving them there would be a good idea.

Jeff

jefndeb said:

Yes, thanks to all for the help. Now I understand how these work.

However does anybody know why Mainship removed all the Horseshoe type collars for all the connections?

All of the fittings at the manifold have no collars on them, at least on my Mainship 40.

They probably are not necessary normally, like in a house but boats move around and vibrate a lot so I would think leaving them there would be a good idea.

Jeff

Click to expand...

I can't see why anyone would do that intentionally.