I just had a kitchen remodel done, and as part of that a plumber added a dedicated water valve for my espresso machine (see picture below). However, I can't seem to find any couplings that fit on this thread and the other side.

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The hose that came with my machine ends with a 1/8" BSP female. I got this adapter from Amazon which has 1/8" BSP male on one side and 1/4" NPT female on the other.

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The 1/8" BSP male side seems to fit into the hose, but the 1/4" NPT female side is too big for the water valve in my kitchen (it goes completely over it without attaching to the thread). Since then I've been looking for some coupling or adapter to convert from 1/4" NPT female to whatever is in that kitchen water valve.

Here's what I've tried:

The 1/4" MIP side fits into the 1/4" FIP of my adapter, but the 1/8" FIP is too small for my water valve.

Used just to gauge the size of the water valve. It's also too big and goes right around my water valve.

This one is interesting. If I take off the cap at the end of this contraption and attempt to thread it on the water valve it works, but 1) I don't know what to do with the rest of it, and 2) it doesn't fit into anything else. I have a feeling that's not what it's meant to be used for.

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Given the above, my questions are:

  1. What kind of fitting does my kitchen valve take?
  2. How do I make it fit into a 1/4" FIP coupling (from the adapter I got from Amazon)?
  • 2
    The installation instructions for the machine should list the size needed, or ask the plumber if it is something they added.
    – crip659
    Apr 2, 2023 at 21:48
  • I will be patiently waiting for that expresso
    – Traveler
    Apr 2, 2023 at 22:46
  • 2
    The "this adapter" is a no-name brand from Amazon and is not lead-free, so technically illegal to install for potable water in the US. Also, such no-name fittings are often not quite the claimed size or length or threading. The other brand you found is a real one, so should be trustworthy.
    – Armand
    Apr 2, 2023 at 22:49

1 Answer 1


Sadly, none of the 4 items you got are usable for this, but at least they should all be returnable for refund :)

Your wall shutoff is a male 1/4" compression connection. The threading on the end is straight, not tapered. FIP and MIP are tapered threading, so while they may seem to fit, they won't work and will either leak or damage the threading on the shutoff valve.

The Everbilt LFA-23 you show has a 1/4" compression end (this is different from a FIP/MIP end; also the small tube serves as an internal support for the compression "olive" area inside the pipe when connecting to a metal pipe). If you want to use plastic pipe/tubing, you need to buy and use an additional plastic internal support tube, according to Home Depot instructions in the QA on the link you posted. Since you don't have any FIP/MIP connections, I would just return it.

Any standard 1/4" compression connection should fit on that shutoff valve, whether rigid metal pipe or a flexible braided water supply hose with an end designed for a 1/4" compression shutoff.

Making a plumbing compression connection with metal pipe is not super difficult but is less forgiving for over- or under- tightening than imho a connection sealed with a rubber gasket/washer inside, like a flexible braided water supply line.

As for your espresso machine hose end, please post a photo of it and measurements (and specs from the manual).

Edit: Assuming you need to connect the wall shutoff to a 1/8 BSP female end (BSP is a straight, not tapered, thread so uses a rubber washer/gasket inside the female end to prevent leaking):

I would use a braided flexible water supply line with 1/4" compression female connectors on each end (often named "icemaker water supply line"). These are available in many lengths, from 12" like that below, to 60" or longer.

enter image description here

Then, just use a male 1/4" compression To male 1/8 BSP adapter. This may be hard to find. Perhaps check with one of the online espresso machine parts stores? I did find a fitting from "Anderson Metals" but their parts all seem to contain lead, and so are potentially hazardous (and illegal) to install on potable water systems.

  • Thanks for the detailed answer! I'd like to use the hose that came with the machine if possible (which ends in 1/8 BSP female), and I'd like to avoid chaining 2 hoses together. Is there a way to do this using just adapters / fittings from that hose to the water shutoff valve?
    – peter
    Apr 2, 2023 at 23:22
  • I can't easily find 1/4-inch female compression adapters; maybe they exist - a plumbing supply house might be able to help you, or an espresso machine supply/repair shop. Personally, I would get rid of the machine's hose and just use a standard icemaker water supply hose with appropriate fitting for whatever connector your machine (not hose end) has. Again, it would help if you could post a photo of both ends of your machine hose and the connector on the espresso machine.
    – Armand
    Apr 3, 2023 at 0:30
  • Makes sense. Do you think this adapter would work? fittings.space/ttc2p-04-02rm
    – peter
    Apr 6, 2023 at 0:07
  • @peter Those both look like male compression ends, with the ferrules etc. The sizing numbers for the other ends don't seem to match the photos either, bu it's hard to tell. That company does seem to encourage phone calls though.
    – Armand
    Apr 6, 2023 at 1:41

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