Viton – the material for the spots that stay hot all the time
Viton is a fluoroelastomer and withstands temperature and chemical stress far better than standard rubber. In a commercial machine that sits hot twelve hours a day, that is not a luxury – it is the reason a seal lasts years rather than months.
The designation 3187 is a size code; R499907384 is the part number. When ordering, the number is what counts: the R9 contains several rings of similar size made from different materials, and they are not interchangeable.
When it is due
A Viton ring rarely fails suddenly. Typically you see slowly increasing seepage at the sealing point that builds up over weeks and at first only shows as a limescale edge.
Once removed, you can tell it is worn out by its hardness: the ring can no longer be pressed in, feels firm and keeps every deformation.
Fine cracks on the outside that open up when you bend it slightly are also a clear sign.
At a glance
| Type |
O-ring, sealing ring |
| Installation location |
Steam and water circuit of the R9 |
| Fits |
Rocket R9, for which the manufacturer lists the number R499907384 |
| Scope of delivery |
one O-ring |
| Part number |
R499907384 |
| Version |
Viton, size designation 3187 |
| Installation |
Installation by a specialist recommended |
| Brand |
Rocket |
Important for installation
The installation point is pressurised and hot. Disconnect the machine from the power supply, depressurise it and let it cool down. Viton is stiffer than soft rubber and is harder to stretch over edges – better to take more time and use a touch of food-safe silicone grease than to use force and risk a tear.
Who it is for
For businesses with an R9 and for workshops that fully renew the sealing rings during an overhaul.
If you only have a leak and do not know the position, narrow down the spot first. We do not have a separate machine category for the R9 – the position can be found via the part number and the Original spare parts.
The O-rings and sealing rings in the Rocket catalogue
Rocket fits a whole series of O-rings in the steam circuit, water circuit and boiler that look very similar from the outside. For most of them, the documentation gives neither the inner diameter nor the cross-section – they can only be reliably distinguished by the part number. That is why we list them individually, with the number in the title or in the table:
-
O-ring steam and water tap – A449904334
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O-ring for the steam and water tap cover – A449904672
-
O-ring steam and water knob, Cellini and Giotto – C400002786
-
O-ring water nozzle, Appartamento to Mozzafiato – C400003008
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O-ring 3-way valve – M449907403
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O-ring S2 valve – M449907143
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O-ring 4250 silicone, R9 – M449905837
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O-ring 3187 Viton, R9 – R499907384
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O-ring drain elbow, Boxer, RE A and R9 – M449905463
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Copper sealing ring heat exchanger – C479900673
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O-ring boiler top, Porta Via – A449906261
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O-ring boiler bottom, Porta Via – A449906262
-
O-ring heating element, Porta Via – A449910266
-
O-ring 18 × 5 mm machine foot, R Cinquantotto – A449906954
If you measure your removed part and do not know the number, send us the model and serial number – we will check it against the exploded view.
What goes with it
Also for the R9: the 4250 silicone O-ring, the valve seal kit and the lever seal kit.
Mechanically related are the steam and water valve and the axle R229905344.
More can be found in Original spare parts and Rocket accessories and spare parts.
Our experience from commercial servicing: Viton rings last a long time, but only if the sealing surface is clean. That is why, before every installation, we use a soft brush and a little descaling solution for the groove – no sandpaper, no blade. A scratched groove ruins any new ring within weeks. This is our own procedure, not a manufacturer requirement. Afterwards we run a series of espressos with Cozy Chocolate until the machine has thermally settled again.
No returns
Original spare parts are excluded from exchange and return. They are sourced specifically for your order and cannot be resold after installation or a test fit on the machine. So check the model, year of manufacture and serial number of your machine before ordering – or drop us a quick message and we will clarify the fit together. Your rights in the event of defective goods remain unaffected.
Frequently asked questions
What does Viton mean?
Viton is a brand name for fluoroelastomer, a sealing material that is particularly resistant to temperature and chemicals.
What does 3187 mean?
It is a size designation from an O-ring standard. What matters for ordering is the number R499907384.
Can I use a silicone ring instead?
We advise against it. The materials have different properties, and the manufacturer selects them according to the installation point.
Does the ring also fit the R9 One?
The documentation lists it for the R9. We use the serial number to check whether your series uses the same position.
Can I see the part at your showroom?
Yes. We are in Bern at Gerberngasse 44 and in Zurich at Hagenholzstrasse 50b. Bring the removed part with you, we will compare it with the replacement on site and you only take home what really fits.
Questions about the fit or the serial number of your machine? Write to us at [email protected]. We deliver across Switzerland and to Liechtenstein in 2-4 working days.
