{"product_id":"rocket-teflon-dichtung-pilzkopfschraube-bruehgruppe","title":"Rocket Teflon Seal for the Brew Group Mushroom-Head Screw – C469900420","description":"\u003cdiv class=\"ccc-mobile-wrapper\"\u003e\n\u003cstyle\u003e.ccc-mobile-wrapper{max-width:880px;margin:0 auto;font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,Helvetica,Arial,sans-serif;color:#1d1d1f;line-height:1.65;font-size:17px}.ccc-mobile-wrapper h2{font-size:1.7em;line-height:1.25;margin:0 0 .6em;font-weight:700}.ccc-mobile-wrapper h3{font-size:1.3em;line-height:1.3;margin:1.8em 0 .5em;font-weight:700}.ccc-mobile-wrapper h4{font-size:1.05em;margin:1.1em 0 .2em}.ccc-mobile-wrapper p{margin:0 0 1em}.ccc-mobile-wrapper a{color:#0b6b5f;text-decoration:underline}.ccc-compare-table{width:100%;border-collapse:collapse;margin:1em 0;font-size:.97em}.ccc-compare-table th,.ccc-compare-table td{text-align:left;padding:10px 12px;border-bottom:1px solid #e3e3e6;vertical-align:top}.ccc-compare-table th{width:42%;font-weight:600;color:#3a3a3c}.ccc-roastery-tip{background:#eff6f4;border-left:4px solid #0b6b5f;border-radius:10px;padding:16px 18px;margin:1.6em 0}.ccc-return-note{background:#fdf3ef;border-left:4px solid #b4532a;border-radius:10px;padding:16px 18px;margin:1.6em 0}.ccc-faq h4{font-weight:700;margin:1.2em 0 .2em}@media(max-width:600px){.ccc-mobile-wrapper{font-size:16px}.ccc-mobile-wrapper h2{font-size:1.45em}.ccc-mobile-wrapper h3{font-size:1.18em}}\u003c\/style\u003e\n\u003ch2\u003eThe seal under the mushroom-head screw\u003c\/h2\u003e\n\u003cp\u003eThe hex screw with the flat, mushroom-shaped head closes off the brew group at a point where hot water is present under pressure. This Teflon washer sits between the head and the group body. It is the only thing that seals there – metal on metal would never hold reliably on a surface like this.\u003c\/p\u003e\n\u003cp\u003eTeflon gives way when tightened and adapts to the surface. That is exactly what makes it seal, and exactly what wears it out: after a few openings the ring is flattened and has no reserve left. Part number C469900420 distinguishes it from the other Teflon seals in the same group, which can hardly be told apart with the naked eye.\u003c\/p\u003e\n\u003ch3\u003eWhen it is due\u003c\/h3\u003e\n\u003cp\u003eA fine damp ring appears under the screw head and comes back after wiping. A whitish limescale ring forms at that spot. The screw can be tightened further than last time without getting any tighter – a sure sign that the material under the head has no height left. And of course whenever you have the group open anyway.\u003c\/p\u003e\n\u003ch3\u003eAt a glance\u003c\/h3\u003e\n\u003ctable class=\"ccc-compare-table\"\u003e\n\u003ctr\u003e\n\u003cth\u003eType\u003c\/th\u003e\n\u003ctd\u003eTeflon seal\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eLocation\u003c\/th\u003e\n\u003ctd\u003eunder the hex screw with mushroom head on the brew group\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eFits\u003c\/th\u003e\n\u003ctd\u003eRocket machines with this brew group – the documentation does not list specific models\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eScope of delivery\u003c\/th\u003e\n\u003ctd\u003eone seal\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003ePart number\u003c\/th\u003e\n\u003ctd\u003eC469900420\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eDesign\u003c\/th\u003e\n\u003ctd\u003eTeflon (PTFE); dimensions and thickness are not documented\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eInstallation\u003c\/th\u003e\n\u003ctd\u003einstallation by a specialist recommended\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003cth\u003eBrand\u003c\/th\u003e\n\u003ctd\u003eRocket\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003ch3\u003eImportant for installation\u003c\/h3\u003e\n\u003cp\u003eThe screw sits in a pressurised line. Disconnect the machine from the mains beforehand and make sure it is depressurised and cooled down – on a group that is still hot, water is under pressure and will shoot out when loosened. Teflon is not retightened: anyone who turns the screw «another eighth» tighter squeezes the material aside and will have the same leak at the next shot. We deliberately do not give step-by-step instructions here.\u003c\/p\u003e\n\u003ch3\u003eWho it is for\u003c\/h3\u003e\n\u003cp\u003eFor anyone who services the brew group of their Rocket themselves and consistently replaces every Teflon surface when opening it. If you are not sure which of the screws on your group is meant, write to us – a photo of the opened group is usually enough for us.\u003c\/p\u003e\n\u003ch3\u003eWhat goes with it\u003c\/h3\u003e\n\u003cp\u003eOften needed in the same job: the \u003ca href=\"\/en\/products\/rocket-teflon-dichtung-entlastungsventil-bruehgruppe\"\u003eTeflon seal for the relief valve\u003c\/a\u003e, the \u003ca href=\"\/en\/products\/rocket-teflon-o-ring-36mm-bruehgruppe\"\u003eTeflon O-ring 36 mm\u003c\/a\u003e, the \u003ca href=\"\/en\/products\/rocket-flachdichtung-bezugshebel-c219900426\"\u003eflat gasket of the brew lever\u003c\/a\u003e and the \u003ca href=\"\/en\/products\/rocket-nockenwelle-bruehgruppe\"\u003ecamshaft of the group\u003c\/a\u003e. For an overview, see \u003ca href=\"\/en\/collections\/zubehor-und-ersatzteile-rocket\"\u003eRocket accessories and spare parts\u003c\/a\u003e and the \u003ca href=\"\/en\/collections\/serviceteile\"\u003eoriginal spare parts\u003c\/a\u003e.\u003c\/p\u003e\n\u003ch3\u003eThe Teflon seals in the Rocket catalogue\u003c\/h3\u003e\n\u003cp\u003eWe stock five Teflon seals individually. They look alike and sit in completely different places – the part number decides, not the shape:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"\/en\/products\/rocket-teflon-dichtung-entlastungsventil-bruehgruppe\"\u003eRelief valve of the brew group, C469900783\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/en\/products\/rocket-teflon-dichtung-pilzkopfschraube-bruehgruppe\"\u003eMushroom-head screw of the brew group, C469900420\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/en\/products\/rocket-teflon-o-ring-36mm-bruehgruppe\"\u003eTeflon O-ring 36 mm for the brew group, C469900421\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/en\/products\/rocket-teflon-dichtung-dampf-wasser-appartamento-tca\"\u003eSteam and water, Appartamento TCA, A469909447\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/en\/products\/rocket-teflon-ring-sicherheitsventil-dampf-wasserhahn\"\u003eSafety valve and steam\/water tap, A449904331\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cdiv class=\"ccc-roastery-tip\"\u003e\n\u003cp\u003e\u003cstrong\u003eFrom our workshop in Bern and Zürich\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eWe never order the small Teflon seals one at a time, but keep two of each number in stock. The reason is unromantic: during reassembly a ring like this likes to fall on the floor, and then it has vanished in the workshop. That is our routine, not a manufacturer requirement. For breaking in afterwards we like the \u003ca href=\"\/en\/products\/cozy-chocolate-natural-brasilien-kaffeebohnen\"\u003eCozy Chocolate\u003c\/a\u003e or the \u003ca href=\"\/en\/products\/nutty-delight-kaffee-blend-brasilien-indien\"\u003eNutty Delight\u003c\/a\u003e; if you want punch and body, go for the \u003ca href=\"\/en\/products\/very-nutty-kraftiger-robusta-aus-indien\"\u003eVery Nutty\u003c\/a\u003e. Everything else is in our \u003ca href=\"\/en\/collections\/kaffeebohnen\"\u003ecoffee beans\u003c\/a\u003e.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"ccc-return-note\"\u003e\n\u003cp\u003e\u003cstrong\u003eReturns excluded\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eOriginal 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 test-fitted on the machine. So check the model, year of manufacture and serial number of your machine before ordering – or drop us a quick line and we will clarify the fit together. Your rights in the event of defective goods remain unaffected.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"ccc-faq\"\u003e\n\u003ch3\u003eFrequently asked questions\u003c\/h3\u003e\n\u003ch4\u003e\u003cstrong\u003eIs this an electrical part?\u003c\/strong\u003e\u003c\/h4\u003e\n\u003cp\u003eNo. It is purely a Teflon seal with no electrical function.\u003c\/p\u003e\n\u003ch4\u003e\u003cstrong\u003eIs the screw included?\u003c\/strong\u003e\u003c\/h4\u003e\n\u003cp\u003eNo. Only the seal is supplied. The mushroom-head screw itself is a separate item and not part of this article.\u003c\/p\u003e\n\u003ch4\u003e\u003cstrong\u003eWhat are the dimensions of the seal?\u003c\/strong\u003e\u003c\/h4\u003e\n\u003cp\u003eFor C469900420, dimensions and thickness are not stated in the documentation. Send us the serial number of your machine and we will check the fit.\u003c\/p\u003e\n\u003ch4\u003e\u003cstrong\u003eIs this the same seal as C469900421?\u003c\/strong\u003e\u003c\/h4\u003e\n\u003cp\u003eNo. C469900421 is the 36 mm Teflon O-ring of the group, a separate item. With Teflon seals, the part number decides, not the appearance.\u003c\/p\u003e\n\u003ch4\u003e\u003cstrong\u003eCan I see the part in your showroom?\u003c\/strong\u003e\u003c\/h4\u003e\n\u003cp\u003eYes. We are in Bern at Gerberngasse 44 and in Zürich at Hagenholzstrasse 50b. Let us know shortly beforehand and we will have the part ready for you.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cp\u003eQuestions about the fit? Write to us at \u003ca href=\"mailto:office@coffeecoachingclub.ch\"\u003eoffice@coffeecoachingclub.ch\u003c\/a\u003e. Delivery across Switzerland and to Liechtenstein in 2-4 working days.\u003c\/p\u003e\n\u003cscript type=\"application\/ld+json\"\u003e{\"@context\":\"https:\/\/schema.org\",\"@type\":\"FAQPage\",\"mainEntity\":[{\"@type\":\"Question\",\"name\":\"Is this an electrical part?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"No. It is purely a Teflon seal with no electrical function.\"}},{\"@type\":\"Question\",\"name\":\"Is the screw included?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"No. Only the seal is supplied. The mushroom-head screw is a separate item.\"}},{\"@type\":\"Question\",\"name\":\"What are the dimensions of the seal?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"For C469900420, dimensions and thickness are not stated in the documentation. Send us the serial number of your machine and we will check the fit.\"}},{\"@type\":\"Question\",\"name\":\"Is this the same seal as C469900421?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"No. C469900421 is the 36 mm Teflon O-ring of the group, a separate item. With Teflon seals, the part number decides, not the appearance.\"}},{\"@type\":\"Question\",\"name\":\"Can I see the part in your showroom?\",\"acceptedAnswer\":{\"@type\":\"Answer\",\"text\":\"Yes. We are in Bern at Gerberngasse 44 and in Zürich at Hagenholzstrasse 50b. Let us know shortly beforehand and we will have the part ready for you.\"}}]}\u003c\/script\u003e\n\u003c\/div\u003e","brand":"Rocket","offers":[{"title":"Default Title","offer_id":56310396256641,"sku":"A02238","price":3.74,"currency_code":"CHF","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0633\/2265\/2931\/files\/A02238_1.jpg?v=1790154201","url":"https:\/\/coffeecoachingclub.ch\/en\/products\/rocket-teflon-dichtung-pilzkopfschraube-bruehgruppe","provider":"Coffee Coaching Club GmbH","version":"1.0","type":"link"}