Fittings for espresso machines

[MrJack]

Picked up a stainless needle valve which I'd like to plumb in to my Bezzera BZ99s as a bypass flow control valve (to mess about with flowrate).

Had a look under the hood yesterday, and think my best option is to put in a couple of tees, and using short sections of 6mm PTFE tubing.

One of the tees will tie in at the upstream end of the PTFE line between the pump discharge and the solenoid. The other at the pump inlet, at the end of the PTFE line from the OPV bypass.

The existing fittings are 1/8" BSP Serto fittings in nickel plated brass (I think). I've seen similar kind of fittings available online, but not sure about the best kind of fitting for the PTFE tube. The OEM lines have an insert and a captive nut.

Anyone know where I can source some of these (sponsors?), or have used them before in an espresso machine?

[sprezzatura]

Picked up a stainless needle valve which I'd like to plumb in to my Bezzera BZ99s as a bypass flow control valve (to mess about with flowrate).

Had a look under the hood yesterday, and think my best option is to put in a couple of tees, and using short sections of 6mm PTFE tubing.

One of the tees will tie in at the upstream end of the PTFE line between the pump discharge and the solenoid. The other at the pump inlet, at the end of the PTFE line from the OPV bypass.

The existing fittings are 1/8" BSP Serto fittings in nickel plated brass (I think). I've seen similar kind of fittings available online, but not sure about the best kind of fitting for the PTFE tube. The OEM lines have an insert and a captive nut.

Anyone know where I can source some of these (sponsors?), or have used them before in an espresso machine?

Pump and irrigation stores carry BSB fittings. Pirtek carries NSP/BSB/BSP and aircraft-style push in (nylon) fittings. Coffee Parts carries some fittings.

[MrJack]

Cheers. I have seen the ones on Coffeeparts and will probably get them if I can't find any here in Perth.

My only concern was the existing fittings on the PTFE line. Have some John Guest threaded fittings which fit, but dont thread on far enough to seal against the insert in the tube.

I'd post a picture, but Tapatalk crashes every time I try.

[sprezzatura]

If you get stuck PM me. I just did a custom bypass for a friend using NS nylon/PTFE tubing. Can source fittings.

[simonko]

I was thinking of doing similar at one stage before I decided to make my BZ99s rotary. 4 mm ID PTFE with M12/1 compression fittings? I recall Pirtek didn't really have anything compatible - the closest was some thing they carried for (now illegal) motorbike brake line repairs.

Neuforce in Sydney show they carry Serto components, you'll see the same sort of elbows on this page, but in SS.

What thread has your needle valve got on it?

Let me know how you go - I'm thinking of using Teflon tubing for a different machine. Which fittings did you end up using Sprezz?

[sprezzatura]

I was thinking of doing similar at one stage before I decided to make my BZ99s rotary. 4 mm ID PTFE with M12/1 compression fittings? I recall Pirtek didn't really have anything compatible - the closest was some thing they carried for (now illegal) motorbike brake line repairs.

Neuforce in Sydney show they carry Serto components, you'll see the same sort of elbows on this page, but in SS.

What thread has your needle valve got on it?

Let me know how you go - I'm thinking of using Teflon tubing for a different machine. Which fittings did you end up using Sprezz?

I had to work with NS calibrated Teflon pipe (4/2.5) but we used M6 and 1/8" NPT press fittings. If you cut them carefully they don't leak and these guys are good to 20bar.

[artman]

Have you tried Enzed? They might have the bits you need? Worth a shot, best to visit in store.

Cheers

[MrJack]

Interested to hear more about the conversion to rotary....

Have been looking through the Neuforce material, but haven't contacted them yet.

My valve has 1/8" female BSP (parallel) connections. My John Guest fittings fit it fine (although I would prefer stainless).

The existing fitting is 6mm OD, 4mm ID PTFE. Thread appears to be BSPP, but not sure (Bezzera diagram says 1/8" G). I think the seal is made between the end of the insert (ferrule?) and the end of the fitting, but there is some kind of insert in the fitting itself, which reduces the internal diameter.

What would actually be ideal is another of the special 90deg male tees used on the inlet...

[MrJack]

Incidentally, turns out the "G" may indicate BSPP with parallel male and female https://en.wikipedia.org/wiki/British_Standard_Pipe

Also discovered the 90deg ("V") tee, amongst the brass range of Serto fittings.

[simonko]

Pretty sure it's a reduction compression fitting - the nut has a tapered collar inside which squeezes the tube against nipple/olive inside the tube when the nut is tightened.

Conversion to rotary went smoothly. A pressure regulator getting the line pressure down to an acceptable range for the pump was quite expensive so decided to get the Brita C150 water filter many of the sponsors here recommend, as that comes with an appropriate 350 kPa regulator. Disconnected tank and pump, brought water into the junction after the pump so it could service both the HX and the boiler fill solenoid. Drive rotary pump from same GICAR output as used to drive the vibe pump. Total bliss not having to hear the vibe pump or run out of water mid-shot, but do miss the inherent softer, ramped infusion from the vibe pump. Puck prep has become much more important.

[sprezzatura]

You can find a double olive pretty easy. The tapered fitting may be tricky; not that you can't purpose make a non-OEM one.

[MrJack]

So... stainless Serto fittings are out of the question. Cost would approach that of the machine ($100 for one tee...).

[sprezzatura]

Yowza! At least BSB is inexpensive.

[MrJack]

I've asked for a price for the brass - hopefully an order of magnitude less

[sprezzatura]

Fittings for espresso machines

Definitely! BSB fittings are a few bucks each. Another good place to look for fittings is a BBQ or gas supply store.