[R&D] High pressure hose connections (clip connectors)

soffee commented

2026-08-03 00:54:06 +03:00

Owner

i'm researching options on connecting pressure sensor to the system.

seems like nobody knows how these ptfe tube connectors called other than "clip connectors", seemingly they don't have public name and the standard is proprietary.

i found this post that describes exactly my frustration: https://www.facebook.com/groups/decentespresso/permalink/706294639554430/

i had some success finding some fittings and pipes itself by searching "coffee fittings", "espresso fittings" on aliexpress.

pipes itself as well as junctions are seemingly easy to find. the problem is converting g1/4 connection of the pressure sensor to these ptfe pipes. there's only "clip connector" to g1/8 adaptor i found and i don't know how accessible they will be in the future

my idea is to try to make my custom CAD model of such an adaptor (g1/4 to "clip connector") and try 3d printing it from resin.

also i will probably get these g1/8 connectors in meantime and get g1/8 to g1/4 adaptors

i'm researching options on connecting pressure sensor to the system. seems like nobody knows how these ptfe tube connectors called other than "clip connectors", seemingly they don't have public name and the standard is proprietary. i found this post that describes exactly my frustration: https://www.facebook.com/groups/decentespresso/permalink/706294639554430/ i had some success finding some fittings and pipes itself by searching "coffee fittings", "espresso fittings" on aliexpress. pipes itself as well as junctions are seemingly easy to find. the problem is converting g1/4 connection of the pressure sensor to these ptfe pipes. there's only "clip connector" to g1/8 adaptor i found and i don't know how accessible they will be in the future my idea is to try to make my custom CAD model of such an adaptor (g1/4 to "clip connector") and try 3d printing it from resin. also i will probably get these g1/8 connectors in meantime and get g1/8 to g1/4 adaptors

soffee commented

2026-08-03 01:08:56 +03:00

Author

Owner

in case of facebook post dying here's backup

John Buckman at Decent Espresso Group wrote:

Connecting everything up

One of the really annoying things about building an espresso machine is that there is no standard way to connect the water tubes between things that do stuff to water. Pumps, heaters, flow meters, valves, steam wands: they all use different fittings.
There are lots of different "standards", most of which are fiddly, can leak if they're not installed perfectly, and they're expensive. How expensive? Well, each connector on our first prototype machine cost $9, and we had 15 of them. $135 in connectors in a machine that sells for $999 is not great. And, one of them completely broke during my two month press tour in November. Marvelous.
And then... there are these connectors that have no name.
You only find them when you open up some models of amazingly super-engineered Nespresso machines. We call them "clip connectors" and they are solid teflon tubing, with a metal sleeve inside, and another one outside. Once the tube is made, it simply pushes in with a rubber gasket, and clips in, and... they seem to never leak, they rotate, they're super easy to install and remove. They're amazing!
What's the catch?
The only hitch is that they are totally proprietary and not available off the shelf. Even the tool for making the tubes (mounting the outer metal ring) isn't available for purchase, and it requires exactitude and a fair amount of compression and force.
Sigh.
We did find one company that would make the tubes with the ends on them, and since nobody will sell us the tool to make it ourselves, we're using them to buy the tubes ready-made. A bit more expensive, but they're our only source at the moment.
For converting between other connector types (such as to the steam wand, or the water heater) to these clip connectors, we've CAD designed our own converters. Today, 50 samples of these two converters arrived (they're the shiny things) and you can see them mounted on the back of the steam wand (first photo) and on both ends of the heater (bottom photo). We're sending a dozen of them to our heater manufacturer, so they can give a price quote for welding these on for us.
Happily, it looks like our connector-adaptor designs are working, so now we can use these great water tubes virtually everywhere.

in case of facebook post dying here's backup _[John Buckman at Decent Espresso Group](https://www.facebook.com/groups/decentespresso/permalink/706294639554430/) wrote:_ > Connecting everything up > > One of the really annoying things about building an espresso machine is that there is no standard way to connect the water tubes between things that do stuff to water. Pumps, heaters, flow meters, valves, steam wands: they all use different fittings. > There are lots of different "standards", most of which are fiddly, can leak if they're not installed perfectly, and they're expensive. How expensive? Well, each connector on our first prototype machine cost $9, and we had 15 of them. $135 in connectors in a machine that sells for $999 is not great. And, one of them completely broke during my two month press tour in November. Marvelous. > And then... there are these connectors that have no name. > You only find them when you open up some models of amazingly super-engineered Nespresso machines. We call them "clip connectors" and they are solid teflon tubing, with a metal sleeve inside, and another one outside. Once the tube is made, it simply pushes in with a rubber gasket, and clips in, and... they seem to never leak, they rotate, they're super easy to install and remove. They're amazing! > What's the catch? > The only hitch is that they are totally proprietary and not available off the shelf. Even the tool for making the tubes (mounting the outer metal ring) isn't available for purchase, and it requires exactitude and a fair amount of compression and force. > Sigh. > We did find one company that would make the tubes with the ends on them, and since nobody will sell us the tool to make it ourselves, we're using them to buy the tubes ready-made. A bit more expensive, but they're our only source at the moment. > For converting between other connector types (such as to the steam wand, or the water heater) to these clip connectors, we've CAD designed our own converters. Today, 50 samples of these two converters arrived (they're the shiny things) and you can see them mounted on the back of the steam wand (first photo) and on both ends of the heater (bottom photo). We're sending a dozen of them to our heater manufacturer, so they can give a price quote for welding these on for us. > Happily, it looks like our connector-adaptor designs are working, so now we can use these great water tubes virtually everywhere. ![image](/attachments/ebfe861c-cb6a-4774-ae7a-f77a95497b4c) ![image](/attachments/4bacccb3-59f1-4cc4-9d99-6bf7e47d4680)

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874 KiB

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1.3 MiB

soffee commented

2026-08-03 02:11:11 +03:00

Author

Owner

pressure sensor of my current choice is XIDIBEI XDB401 with I2C interface and measurements range 0..3 MPa
they're shipped with g1/4 (BSPT?) but manufacturer also offer customizing the fitting if you contact them.
so i will try to contact them and ask if they can maybe ship it with g1/8 BSPT

but idk i don't really want to rely on these "clip" to g1/8 connectors because there's only one seller selling them and i think they're pretty rare.

my best bet is on custom adaptors from resin, i don't see them breaking from these 15-20 bar.

i will research more into resin printed high pressure applications and post results later (if i won't forget)

pressure sensor of my current choice is XIDIBEI `XDB401` with I2C interface and measurements range 0..3 MPa they're shipped with g1/4 (BSPT?) but manufacturer also offer customizing the fitting if you contact them. so i will try to contact them and ask if they can maybe ship it with g1/8 BSPT but idk i don't really want to rely on these "clip" to g1/8 connectors because there's only one seller selling them and i think they're pretty rare. my best bet is on custom adaptors from resin, i don't see them breaking from these 15-20 bar. i will research more into resin printed high pressure applications and post results later (if i won't forget)

soffee commented

2026-08-03 16:23:25 +03:00

Author

Owner

@soffee wrote in #1 (comment):

pressure sensor of my current choice is XIDIBEI XDB401 with I2C interface and measurements range 0..3 MPa they're shipped with g1/4 (BSPT?) but manufacturer also offer customizing the fitting if you contact them. so i will try to contact them and ask if they can maybe ship it with g1/8 BSPT

they have similar sensor with model name XDB301, they're shipped with g1/8

@soffee wrote in https://git.soffee.space/soffee/kitfort-schematic/issues/1#issuecomment-27: > pressure sensor of my current choice is XIDIBEI `XDB401` with I2C interface and measurements range 0..3 MPa they're shipped with g1/4 (BSPT?) but manufacturer also offer customizing the fitting if you contact them. so i will try to contact them and ask if they can maybe ship it with g1/8 BSPT they have similar sensor with model name `XDB301`, they're shipped with g1/8

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[R&D] High pressure hose connections (clip connectors) #1