Adapters and reducers for water filters

The ASV7 angle valve adapter from John Guest is the ideal choice when you need to connect a 3/8" plastic tube to your water filter or reverse osmosis system. It is mounted directly onto the cold water angle valve under the sink, creating a stable and secure connection.Equipped with an integrated check valve, the adapter protects your water installation against backflow. The built-in shut-off valve allows for easy water supply interruption, making filter changes and maintenance particularly convenient. A practical and reliable spare part for various kitchen and water treatment applications.Thanks to robust brass connections and premium plastic components, the ASV7 guarantees long-lasting performance and a reliable seal. John Guest stands for quality you can trust in every installation.Benefits at a glance:Compatible with 3/8" plastic tubingCheck valve for backflow protectionShut-off valve for convenient maintenanceStrong brass and plastic constructionSuitable for filter systems and water installationsThe product range is not suitable for compressed air, explosive gases, petroleum, or other liquids or in heating systems or similar applications.

The ASV9 angle valve adapter from John Guest is the perfect solution for connecting water filters, reverse osmosis systems and other appliances directly to your cold water supply. With its precise 3/8" thread and 1/4" tube connection, it offers the standard size for most water filter systems, ensuring maximum compatibility.The built-in check valve reliably prevents backflow into the water line, while the integrated shut-off valve makes it easy to stop the water flow whenever maintenance or filter replacement is required. This ensures safety and convenience for your water filter or reverse osmosis system.Made from durable brass and high-quality plastic, the ASV9 provides a secure and long-lasting connection. With this John Guest spare part, you get proven quality and reliable performance for your water installation.Benefits at a glance:Standard 1/4" size for reverse osmosis systems and water filtersIntegrated check valve for safe operationConvenient shut-off valve for easy maintenanceHigh-quality materials for long-lasting useSuitable for coffee machines, water dispensers and water treatmentThe product range is not suitable for compressed air, explosive gases, petroleum, or other liquids or in heating systems or similar applications.

Experience maximum flexibility and reliability when installing your water filter system. This faucet connection adapter with aerator and wastewater return connects your faucet to a 1/4″ tube system. It is an excellent spare part or upgrade for water filters, reverse osmosis systems and replacement components. The connection uses an M22 female thread (IG) ensuring a smooth link between your faucet and your filtration unit.With a well-thought-out design you benefit from convenient handling: The built-in aerator (perlator) provides a steady, splash-free water flow — perfect for use with a 1/4″ hose equipped RO system or direct water filter. The integrated return line for wastewater ensures excess water is neatly redirected, increasing the efficiency of your RO unit and simplifying discharge.The adapter perfectly complements your filtration setup and is finished in a chrome-look design with durable build. Whether at home, in a camper van or on the move — connecting your water filter or RO system becomes effortless. This adapter is compatible with the following VISION AQUA water filters:VA-Basic – travel water filter kit, reverse osmosis water filterVA-Basic PLUS – mobile water filterVanLife – water filter for campers and motorhomesBenefits for you at a glance:Direct M22 female thread to 1/4″ tube – perfect for water filters & RO systemsBuilt-in aerator ensures comfortable, splash-free flowWastewater return line included – clean dischargePremium workmanship – durable and functionalCompatible with VA-Basic, VA-Basic PLUS and VanLife by VISION AQUA

The John Guest adapter with 3/4“ female BSPP thread to 3/8“ tube connection is the right choice when larger systems with higher flow rates need to be connected. It provides a secure and precise link between the angle valve and your water treatment equipment.The adapter is mounted directly on the 3/4“ cold water inlet under the sink and enables the connection of reverse osmosis systems, professional water filters, coffee machines or water dispensers. In our water filter systems, it is used together with the Hydro Stopper, ensuring a reliable and tight installation at the angle valve.Thanks to the precise John Guest engineering, this adapter ensures a stable and long-lasting fit. For anyone seeking a trustworthy spare part for drinking water systems, this adapter combines safety, durability and easy handling in one.Customer Benefits at a Glance:3/8” connection for systems with higher water flowUse in combination with the Hydro Stopper at the angle valveSuitable for reverse osmosis, water filters, coffee machines and water dispensersPremium John Guest quality and durabilityLong-lasting, leak-proof connection for drinking water applications

The John Guest adapter with 3/4“ female BSPP thread to 1/4“ tube connection is the perfect accessory to connect water filters and reverse osmosis systems safely to your cold water supply. Since 1/4" is the standard size for most drinking water filters, this adapter is the ideal choice for under-sink installations.The adapter is mounted directly on the 3/4" cold water supply at the angle valve and ensures a leak-proof connection for water filters, reverse osmosis systems, coffee machines or water dispensers. In our water filter systems, it is specifically used together with the Hydro Stopper, which is installed at the angle valve. This makes the installation quick, secure and highly reliable.With the proven John Guest quality, you benefit from a robust and durable fitting that perfectly integrates into your existing setup. Handling is simple, the connection is leak-free, and it is ideally suited for drinking water applications. An essential spare part for anyone who values safe and clean water.Customer Benefits at a Glance:Standard size 1/4” – perfect for reverse osmosis systems and water filtersDesigned for use with the Hydro Stopper at the angle valveCompatible with coffee machines, water dispensers and water treatment systemsDurable and reliable John Guest qualityQuick and easy installation without toolsThe connectors are also ideal for air, non-flammable gases (e.g. N2 and CO2) and vacuum applications.

The John Guest Push-Fit Connector 15 mm x 3/4" Male Thread (Part No. PM011516E) provides a dependable and durable solution for connecting tubing in water filters, reverse osmosis systems, and filtration equipment. Designed for precision and safety, it ensures a tight and reliable seal that supports long-lasting performance in both residential and commercial applications.Made from high-quality acetal material, this fitting delivers excellent resistance to pressure and temperature changes. It fits perfectly into home water filters, drinking water systems, and professional filtration setups. The quick-connect design allows for easy installation and removal without the need for tools, making maintenance and system upgrades straightforward and efficient.With this original John Guest fitting, users benefit from proven quality and reliability. The precisely machined threads and smooth push-fit connection ensure a leak-free performance, even under demanding conditions. It’s the perfect choice for anyone who wants to maintain or expand their water purification system with trusted components.Key Benefits:Connects 15 mm OD tubing to 3/4" female thread (BSPF)Fast, tool-free installationLeak-proof and long-lasting performanceFood-grade and safe for drinking water systemsIdeal for water filters, reverse osmosis units, and spare partsGenuine John Guest qualityThe connectors are also ideal for air, non-flammable gases (e.g. N2 and CO2) and vacuum applications.

Transform your faucet into a compatible interface for your filtration or reverse osmosis system in no time. This high-quality adapter allows conversion from a male thread size M24 (external) to M22 (external), making it the perfect solution for anyone retrofitting a water filter, RO system or needing replacement parts. Made from durable brass with a chrome-plated finish, it guarantees long-lasting performance with effortless handling. According to manufacturer specifications, dimensions are approx. 21.5 × 23.5 mm, weighing about 16 g including a food-safe EPDM seal.Thanks to this adapter you can connect standard water filters and RO systems without complex modifications. Whether it’s a countertop water filter, under-sink RO installation or a component replacement – this adapter provides a secure connection, reducing the risk of leaks. The chrome finish also adds corrosion resistance and ensures a clean look in your kitchen or utility area.With this adapter you invest in a hassle-free upgrade of your water setup: you gain compatibility, keep flexibility and stay ready for modern filter and RO technologies.Benefits at a glance:Compatibility M24 – M22: suitable connection for many water filters and reverse osmosis unitsPremium brass with chrome finish: durable, corrosion-resistantFood-safe EPDM seal included: secure sealing without additional partsPerfect as a replacement part or retrofit kit for filter and RO systemsEasy installation: screws directly onto existing faucetFlexible connection solution: avoids needing to replace the faucetProperties: Material: brass Weight: 16g Overall Size: 21.5 x 23.5mm / 0.85" x 0.93" (H*D) Finish: Electroplated finish External thread diameter: M24 to M22 incl. food-safe EPDM seal 

The John Guest Bulkhead Connector 3/8" is the perfect choice for installations requiring larger tubing to pass securely through housings or panels. With its threaded body and supplied lock nut, the connector can be tightly fastened, ensuring a stable and durable bulkhead fitting even in systems with higher flow rates.Installation is fast and straightforward thanks to John Guest’s push-fit technology. Simply insert the tube and the connection locks firmly in place, creating a reliable, leak-free seal. This makes the 3/8" bulkhead connector particularly well-suited for reverse osmosis and water filter systems with greater capacity.Constructed from food-grade plastic and equipped with a strong fixing nut, this connector provides long-lasting, hygienic performance for professional water treatment setups.Key Benefits:3/8" size for higher flow applicationsSecure bulkhead fitting through housings and panelsLocking nut provides strong and stable fixationQuick-Connect system for hassle-free installationFood-grade material for safe drinking water applicationsThe product range is not suitable for compressed air, explosive gases, petroleum or other liquids as well as in heating systems or similar areas of application.

The John Guest bulkhead reducer connector delivers precision, reliability, and long-lasting performance. Designed to securely connect two tube systems with different outer diameters – 12 mm and 3/8" – it ensures a leak-free connection in water filtration systems, reverse osmosis units, and beverage equipment.Its durable plastic construction resists pressure, moisture, and temperature variations. Thanks to the quick connect system, installation takes only seconds with no tools required. Perfect for panel or housing installations, this connector guarantees a firm and secure fit.This reducer connector offers maximum flexibility for a wide range of water applications. It provides a dependable solution for water treatment, aquariums, and filter systems while maintaining consistent water flow even during component replacements or cleaning.Customer Benefits at a Glance:Compatible with 12 mm and 3/8" OD tubingStrong, pressure-resistant plastic constructionQuick and tool-free installationIdeal for reverse osmosis units, water filters, and beverage dispensersPerfect for panel mounting applicationsHygienic, low-maintenance, and durableThe connectors are also ideal for air, non-flammable gases (e.g. N2 and CO2) and vacuum applications.

The John Guest Female Adaptor PI451213S is a premium connector designed for 3/8" tube (OD) to 3/8" BSP female thread. It offers a reliable, precise fit and an effortless installation experience – perfect for water filters, reverse osmosis systems, and other beverage or water treatment setups.Made from durable, food-grade plastic, this fitting ensures a leak-free and secure connection, even under continuous use. The John Guest push-fit technology allows quick assembly without tools, making it the ideal choice for both professional installers and DIY enthusiasts.Whether used as a replacement part or for new system installations, this adaptor combines durability, safety, and outstanding performance for all types of water filtration systems.Key Benefits:Quick and secure connection without toolsCompatible with 3/8" OD tube and 3/8" female threadPerfect for water filters, RO systems, and beverage setupsGenuine John Guest quality – long-lasting and reliableMade from food-grade, hygienic materialsMaintenance-free and reusableThe connectors are also ideal for air, non-flammable gases (e.g. N2 and CO2) and vacuum applications.

The PM series for metric tube dimensions is made from black acetal copolymer (POM) plastic and is equipped with food-safe nitrile O-rings.The product range can be used in particular for liquid media, air and inert gases and is therefore also suitable for N2 and CO2. The PM series products are also suitable for pneumatic and vacuum applications in a wide variety of industrial sectors.Properties:     simple and quick installation "right first time"     ideal for compressed air and liquids     mountable without tools     fast, multiple disconnection possible     very good flow propertiesThe connectors are also ideal for air, non-flammable gases (e.g. N2 and CO2) and vacuum applications.

Upgrade your filtration system with this high-quality M24 male to M22 male faucet adapter — perfect for connecting your filter or reverse osmosis unit with ease. It ensures a secure, leak-free interface between your tap and your water filter system, making it an essential replacement part for water purification setups.Whether you’re retrofitting your kitchen or maintaining an existing system, this adapter delivers reliable performance. Crafted from durable brass with an electro-polished finish, it resists corrosion and stands up to continuous use. The included food-safe EPDM seal guarantees secure installation and clean water flow.Trust in a solution that streamlines your setup and keeps your water treatment system running at its best. Be it an upgrade or a replacement part — this adapter delivers both quality and peace of mind.Benefits at a glance:Perfect fit: M24 male thread to M22 male thread — ideal for water filters, RO systems and replacement partsDurable brass construction with polish finish — built to lastIncludes food-safe EPDM seal — secure and leak-free connectionCompact, easy to install — fits seamlessly into your systemExcellent upgrade or spare part for filter systemsProperties: Material: brass Weight: 12g Overall Size: 12.5 x 23.5mm / 0.49" x 0.93" (H*D) Finish: Electroplated finish External thread diameter: M24 to M22 incl. food-safe EPDM seal 

The PM series for metric tube dimensions is made from black acetal copolymer (POM) plastic and is equipped with food-safe nitrile O-rings.The product range can be used in particular for liquid media, air and inert gases and is therefore also suitable for N2 and CO2. The PM series products are also suitable for pneumatic and vacuum applications in a wide variety of industrial sectors.Properties:     simple and quick installation "right first time"     ideal for compressed air and liquids     mountable without tools     fast, multiple disconnection possible     very good flow propertiesThe connectors are also ideal for air, non-flammable gases (e.g. N2 and CO2) and vacuum applications.

The John Guest Push-Fit Elbow Connector 3/8" Stem to 1/4" Tube OD offers a fast, secure, and leak-free connection for water filters, reverse osmosis systems, and other drinking water applications. Built from high-quality, food-grade materials, this fitting ensures lasting performance and reliability in both home and professional environments.Its compact 90° design allows for neat, space-saving installation behind appliances or under sinks. The push-fit technology enables quick assembly without tools or sealing tape. The precision-engineered connection holds the tubing firmly in place, making maintenance and replacement simple and efficient.Whether used as a spare part for your reverse osmosis system, an upgrade for your water filter, or for custom water projects, this John Guest connector delivers professional-grade performance and durability. Trusted worldwide, John Guest fittings represent the highest standards in water connection technology.Key Benefits:Fits 3/8" stem to 1/4" tube outer diameterQuick, secure push-fit connectionMade from food-grade, pressure-resistant plasticPerfect for RO systems, water filters, and beverage linesCompact 90° design for tight spacesGenuine John Guest qualityThe product range is not suitable for compressed air, explosive gases, petroleum or other liquids as well as in heating systems or similar areas of application.

The John Guest push-fit elbow connector in 3/8" is designed for water filtration systems, reverse osmosis units and setups requiring larger tube sizes. With its push-fit technology, connections are made quickly and securely without tools. This ensures a clean and hassle-free installation every time.Its durable construction guarantees leak-free performance, even when operating under pressure. The 3/8" version is especially suitable for applications where higher flow rates are required, making it a reliable choice for advanced filtration systems.Like all John Guest spare parts, this elbow connector offers long-lasting quality, food-grade safety and simple handling. It’s the right solution for anyone who wants to upgrade or maintain their water system with trusted components.Key Benefits:Ideal for 3/8" water filters and RO systemsQuick installation with proven push-fit technologySecure and leak-proof connectionsLong-lasting, food-grade materialGenuine John Guest spare partThe product series is not suitable for use in compressed air and vacuum areas.

The John Guest Push-Fit Connector 3/8" Tube OD to 1/2" NPTF Male Thread provides a secure and durable connection for water filters, reverse osmosis systems, and a wide range of drinking water applications. Its easy push-fit design ensures a tight, leak-free seal and allows for quick installation without the need for special tools. Simply push in, tighten, and the connection is ready.Made from strong, food-grade acetal, this connector delivers excellent resistance to pressure and temperature variations. It’s an ideal choice for use in water filtration systems, aquariums, beverage dispensers, and refrigerators with water connections. Precision manufacturing guarantees a perfect fit and long-lasting reliability between tube and thread.Whether used as a replacement part or for building a new filtration system, this John Guest connector ensures consistent performance and ease of use. Its proven push-fit technology saves time during assembly while maintaining maximum safety for your drinking water.Customer Benefits at a Glance:Fast, tool-free installationDurable, food-grade materialIdeal for RO systems and water filtersReliable, leak-proof connectionPerfect as a replacement or for new setupsThe product range is not suitable for compressed air, explosive gases, petroleum or other liquids as well as in heating systems or similar areas of application.

The John Guest Bulkhead Connector 1/4" is designed for secure and leak-free tubing installations through panels or housings. Featuring a threaded body and a durable locking nut, the connector can be firmly fixed in place, providing a stable bulkhead fitting. This makes it ideal for use in water filter systems, reverse osmosis units and other water treatment setups.The 1/4" size is the industry standard for most water filtration systems, making this connector the perfect choice as a spare part or when building a new installation. Thanks to John Guest’s Quick-Connect technology, connecting tubing is effortless: simply push the tube into the fitting for a reliable and watertight connection.Made from food-grade plastic and reinforced with a sturdy lock nut, the connector ensures both long-term hygiene and durability. It allows professional, stable and efficient construction of water filtration systems without the hassle of complicated assembly.Key Benefits:Standard 1/4" size for most water filters and RO systemsSecure bulkhead fitting through panels or housingsLocking nut provides stable fixationQuick-Connect system for leak-free connectionsFood-grade material ensures safe water useThe product range is not suitable for compressed air, explosive gases, petroleum or other liquids as well as in heating systems or similar areas of application.

The John Guest Push-Fit Connector 1/4" Tube OD to 1/4" Female NPTF USA offers exceptional reliability and precision. Designed for use in water filters, reverse osmosis systems, and beverage dispensers, this connector ensures a secure and leak-free connection while maintaining high water quality standards. Made from durable, food-grade materials, it guarantees long-lasting performance even under continuous use.Installation is quick and effortless thanks to the push-fit technology. Simply insert the tube, and the connection locks firmly into place without the need for any tools. This makes it the perfect choice for users who value efficiency, cleanliness, and durability in their water purification systems.Manufactured by John Guest, a trusted name in fluid control fittings, this connector stands for top-tier quality and user-friendly design. Its compatibility with 1/4" tubing and 1/4" threads makes it versatile and easy to integrate into new or existing systems.Key Benefits:Secure, leak-free connection for water filters and RO systemsQuick tool-free installationFood-grade, durable plasticHygienic, corrosion-resistant, and long-lastingIdeal for drinking water, filtration, and cooling applicationsThe product range is not suitable for compressed air, explosive gases, petroleum or other liquids as well as in heating systems or similar areas of application.

The John Guest Tap Connector PP3212U7W provides a secure and precise connection between 3/8" tubing and a 7/16"-24 UNS female thread. This thread type is compatible with standard 7/16"-24 UNF male fittings, commonly found in water filters, reverse osmosis systems, CO₂ setups, and beverage equipment. It fits perfectly with matching UNF or UNS male threads used on faucet adapters, filter heads, or quick-connect fittings.With its trusted push-fit technology, installation takes just seconds – simply push the tubing in and enjoy a tight, leak-free seal. Made from high-quality, food-grade acetal, this connector ensures hygiene, durability, and long-lasting reliability for all drinking water applications.Whether used for maintenance or new installations, this John Guest connector delivers top-tier performance and ease of use. Precision engineering ensures a strong, reusable connection and consistent water flow – ideal for anyone who values clean, safe, and efficient water systems.Key Benefits:Fits 3/8" tubing and 7/16"-24 UNS female thread (compatible with UNF male fittings)Quick and secure push-fit installation, no tools neededFood-grade, durable plastic for hygienic and leak-free operationReusable, long-lasting, and maintenance-friendlyThe product range is not suitable for compressed air, explosive gases, petroleum or other liquids as well as in heating systems or similar areas of application.

The John Guest Tap Connector CI320816FS combines premium quality with effortless installation. It’s the perfect choice for connecting water filters, reverse osmosis systems, and other drinking water applications. The precisely machined fittings ensure a secure, leak-free connection between a 1/4" tube (outer diameter) and a 3/4" female thread. Quick to install and highly reliable – no special tools required.Made from durable, food-grade plastic, this connector is approved for use with drinking water and built to last. It provides excellent resistance to pressure and temperature changes, making it a dependable part of RO systems or water dispensers. Its robust design maintains hygienic water flow and minimizes any risk of leakage.Whether for home, hospitality, or laboratory setups, this tap connector is a smart replacement part that delivers both safety and quality. With the trusted John Guest push-fit system, installation takes only seconds, while the connection remains secure yet easily removable if needed.Customer Benefits at a Glance:Perfect for water filters, RO systems, and drinking water setupsDurable, food-grade materialQuick and tool-free installationReliable and leak-proof John Guest connectionExcellent as a replacement or system extensionThe product series is not suitable for use in compressed air and vacuum areas.

The John Guest PP011223W male connector provides a secure and reliable connection between a 3/8" tube (OD) and a 3/8" internal thread. Designed for use in water filters, reverse osmosis systems, and beverage equipment, this fitting ensures a tight and leak-free seal. The push-fit technology allows for quick, tool-free installation – simply insert the tube for a firm and watertight connection.Made from durable, food-grade polypropylene, this connector offers excellent resistance to pressure, temperature, and corrosion. It’s ideal for applications where hygiene and water purity are critical. Thanks to its precision design, the PP011223W maintains a consistent seal, even with frequent use or system adjustments.Perfect for expanding or maintaining RO systems, water filtration setups, or beverage dispensers, this John Guest fitting serves as a dependable spare part or component for custom installations.Key Benefits:Quick, tool-free push-fit connectionConnects 3/8" tube to 3/8" female threadFood-grade, durable polypropylene constructionIdeal for water filters, RO systems, and beverage equipmentResistant to pressure and temperatureHygienic, long-lasting, and easy to cleanThe product range is not suitable for compressed air, explosive gases, petroleum or other liquids as well as in heating systems or similar areas of application.

The John Guest Tap Connector PP3208U7W is the ideal solution for a secure and quick connection in water filters, reverse osmosis systems, and beverage equipment. Its precise fit and trusted John Guest quality ensure a leak-proof connection without the need for additional tools. The smart push-fit design allows for effortless installation and easy maintenance.Made from durable, food-grade plastic, this connector guarantees long-lasting performance and hygienic safety. It’s designed for drinking water applications and provides a reliable seal between a 1/4" outer diameter tube and a 7/16"-24 UNS female thread.Whether used as a replacement part or for building a new water filtration system, this connector offers top performance and compatibility with a wide range of systems. Choose professional-grade quality that makes a difference – choose John Guest.Customer Benefits at a Glance:Quick and easy installation with push-fit technologyCompatible with water filters, RO systems, and cooling unitsMade from food-grade, durable materialsLeak-proof and secure even after repeated usePerfect for repairs or system extensionsThe product range is not suitable for compressed air, explosive gases, petroleum or other liquids as well as in heating systems or similar areas of application.

The PP series for imperial tube dimensions is made from white polypropylen (PP) plastic and is equipped with food-safe EPDM O-rings.The product range was developed for drinking water applications, water treatment systems etc.Properties:     for drinking water applications and water treatment systems     Polypropylene (PP)     mountable without tools     fast, repeated disconnection possible     very good flow propertiesThe product range is not suitable for compressed air, explosive gases, petroleum or other liquids as well as in heating systems or similar areas of application.

The PI Series for imperial tubing is manufactured from gray acetal copolymer (POM) and features food grade nitrile O-rings.It was developed for food, drinking water applications, water treatment systems, etc.Propertiesfor drinking water applications and water treatment systemsacetal copolymer (POM)mountable without toolsquick, multiple release of the connection possiblevery good flow propertiesThe connectors are also ideal for air, non-flammable gases (e.g. N2 and CO2) and vacuum applications.

The John Guest push-fit elbow connector in 1/4" is the preferred choice for connecting water filter systems and reverse osmosis units. As the standard size in most filtration setups, it ensures a perfect fit and an effortless installation. No tools are required, making it quick and convenient to use.Thanks to the trusted push-fit technology by John Guest, the connector provides a secure and leak-proof connection. It keeps water lines sealed even under higher pressure, making it ideal not only for water filters but also for various applications where clean water is essential.Manufactured from food-grade, durable materials, this connector is designed to last and maintain hygienic conditions. As a genuine John Guest spare part, it delivers the quality and reliability you need for your water system. Perfect for anyone who values safety, simplicity and long-term performance.Key Benefits:Compatible with standard 1/4" water filters and RO systemsQuick and tool-free installationFood-grade and durable materialGenuine John Guest qualityLeak-proof even under higher pressureThe product series is not suitable for use in compressed air and vacuum areas.