The copper ring that gets an opened threaded fitting tight again
Copper is soft enough to conform to every small irregularity of the sealing surface as it is tightened, and hard enough to hold afterwards. That is exactly why threaded fittings in the water and steam path use flat copper washers rather than rubber rings. This one measures 27 by 21 millimetres with a thickness of 1.5 millimetres, as stated in the item name.
The catch: the deformation only works once. Once the fitting has been loosened, the ring is compressed and no longer seats cleanly when tightened a second time. It may still seal, or perhaps only after overtightening – and then you end up with a stripped thread instead of a damp patch. We don't know of a part number for this ring: it is neither in our original spare parts list nor in the catalogue we otherwise take the numbers from. We don't make one up.
When it's due
- The fitting was opened for a service – a new ring always goes in.
- A damp patch, a drip or a white rim of limescale shows up at the fitting.
- The old ring is visibly compressed, warped or torn.
- Last time, the connection could only be made tight by excessive tightening.
At a glance
| Type |
Flat copper sealing ring |
| Installation location |
Between the sealing surfaces of a threaded connection |
| Fits |
La Marzocco threaded fittings with a 27 x 21 mm sealing surface. We have no documentation on where on the machine this size is used – measure the old ring or send us the model and serial number. |
| Scope of delivery |
One copper sealing ring. |
| Specification |
27 x 21 x 1.5 mm, copper. The dimensions are taken from the item name; we have no hardness specification. |
| Installation |
Installation by a qualified professional recommended |
| Brand |
La Marzocco |
Important for installation
The ring sits in a connection that carries hot water or steam under pressure. Work is only ever done on a machine that is switched off, cooled down and depressurised. Both sealing surfaces must be clean and free of nicks, otherwise even a new ring won't help, and the ring belongs flat in its seat, not at an angle.
A copper ring is never used twice, and it is not helped along with sealants. We deliberately don't publish step-by-step instructions here; if you're unsure, have the service done for you.
Who it's for
For workshops and anyone who works on their own La Marzocco and doesn't want to cut corners in the wrong place when reassembling it. A ring costs next to nothing; a damp patch under the machine costs considerably more.
If you're not sure which size sits on your fitting: we stock several copper seals and washers side by side – the quickest way is to measure the old ring.
Goes well with
From our workshop in Bern and Zurich
In Bern and Zurich, before every major service we lay out the copper rings in the sizes we are going to open – having to head out again afterwards because a ring is missing has cost us enough evenings. And we lay the old rings out in order on a cloth instead of tossing them into a bowl; that way it's clear at the end which one went where. This is our routine, not a manufacturer specification. Afterwards we pull the coffee with Nutty Delight or Cozy Chocolate, or with Very Nutty for something stronger. You'll find all of them under Coffee beans.
Returns excluded
Original spare parts are excluded from exchange and return. They are procured specifically for each order and cannot be resold once they have been installed or trial-fitted on a machine. So before ordering, check the model, year of manufacture and serial number of your machine – or drop us a quick line and we'll clarify the fit together. Your rights in the event of defective goods remain unaffected.
Frequently asked questions
Where does this ring sit in the machine?
We have no documentation on that, and we don't guess. What matters is the sealing surface: 27 by 21 millimetres. Measure the old ring, and the new one will fit.
Can I reuse the old copper ring?
We advise against it. Copper deforms when it is first tightened and no longer seats cleanly afterwards. A new ring is cheaper than a second attempt.
Can I do the replacement myself?
As part of a service, yes, but only on a machine that has cooled down and is depressurised. If you're unsure, we'll take care of it in Bern or Zurich.
What is the part number?
We don't know of a number for this ring, and we don't make one up. If you have a number from a service document, send it to us so we can cross-check it.
Can I see the part in your showroom?
Our showrooms in Bern (Gerberngasse 44) and Zurich (Hagenholzstrasse 50b) show a wide selection, but not our entire range – the display changes. Drop us a quick line at [email protected] before your visit, and we will check whether the product you have in mind is currently there.
Questions about fit? Write to us at [email protected]. We deliver across Switzerland and to Liechtenstein in 2-4 working days.
