John Guest connectors for motorhomes, campers and caravans: most common sizes, tubes and fittings
Many motorhome, camper, caravan, small boat and mobile-vehicle users come to Install Beer looking for John Guest connectors to repair a leak, change a pump, connect a tap, adapt a heater, install an external inlet or redo part of the water circuit. Although Install Beer mainly uses John Guest for beverage dispensing, water, filtration and technical systems, many sizes match those used in mobile vehicles: especially the semi-rigid 12 mm tube and adaptors to BSP threads.
Quick summary
In motorhomes, campervans and caravans, the most common size for fresh water circuits is semi-rigid tubing with 12 mm outside diameter. The most sought-after connectors are usually 12 mm straight union, 12 mm elbow, 12 mm tee, 12 mm shut-off valve, 12 mm check valve, 12 mm end plug, 12 mm bulkhead fitting, locking clips, collet covers, 12 mm to 1/2" BSP adapters, 12 mm to 3/8" BSP adapters, straight or elbow tap connectors and 12 mm tubing in blue, red or black.
The key idea: measure the pipe on the outside, not on the inside
In John Guest push-fit fittings, tube size is identified by the outside diameter. If the tube is 12 mm, the fitting must be for 12 mm outside diameter tube. It must not be confused with inches, BSP threads or hose inside diameter. This confusion is the most frequent cause of incorrect purchases when repairing campers and motorhomes.
This article complements the John Guest collection
This guide helps you identify sizes, fitting families and common uses in mobile vehicles. To buy specific parts, check stock or search for connectors by format, see the John Guest fittings collection and the connectors and fittings category. If you have an old part or a mixed installation, the safest option is to measure and confirm before replacing anything.
Downloadable John Guest 12 mm guide for caravans and motorhomes
For those who need to identify specific references, sizes and connector families, we have added as a technical resource the official John Guest / RWC 12mm Caravan and Motorhome Hangsell Retail Guide. This document includes 12 mm fittings, BSP adapters, elbows, tees, straight unions, bulkhead fittings, clips, valves, check valves, LLDPE tubing, inserts and the WaterMarked Speedfit Twist & Lock range.
This document is especially useful if you are repairing a water installation in a camper, caravan or motorhome and want to compare references such as PM0412E1P, PM0312E1P, PM0212E1P, PM011204E1P, CM451214FS1P, PPMSV041212W, 12SCV1P, PEM0412W2P, PEM0312W2P or PEMSTC12142P.
Guide contents
- What is used in motorhomes and campers
- John Guest ranges for 12 mm
- Most common sizes
- Why 12 mm tube dominates
- Official John Guest 12 mm references
- WaterMarked Twist & Lock
- Inch equivalents
- Which fitting to use in each area
- Connection to water pumps
- Connection to taps and sink
- Connection to heaters and boilers
- How to install a push-fit fitting
- Recommended emergency kit
- Common mistakes
- What to buy at Install Beer
- Frequently asked questions
What is used in motorhomes, campers and caravans
The mobile vehicle market uses systems that are lightweight, compact and easy to repair. That’s why push-fit connectors are so common: they allow assembly and disassembly with no soldering, no glues and no complex tools. In a confined space, such as inside a camper kitchen cabinet, this is a major advantage.
In practice you will find three main families of parts: 12 mm semi-rigid pipe for hot/cold water, adapters to BSP threads for pumps, taps or heaters, and small branches or transitions to flexible hose, 10 mm, 3/8" or 1/2" depending on the equipment installed.
Dominant size for fresh water in motorhomes, campers, caravans and many van conversions.
Very common on pumps, filters, taps, heaters, through-bulkhead fittings and hydraulic accessories.
Essential when mixing tubes, hoses, threads, pumps, tanks and equipment from different manufacturers.
John Guest ranges for caravanning: Hangsell, Twist & Lock and DIY kits
John Guest organises the 12 mm universe for caravanning into several families. For the end user, what matters is not only the shape of the fitting, but also whether it belongs to a standard range, a WaterMarked Twist & Lock range, a threaded part, a valve, a safety accessory or a repair kit.
| Family | What’s included | When it is of interest | Example parts |
|---|---|---|---|
| 12 mm Caravan & Motorhome Hangsell Range | 12 mm push-fit fittings in retail format: elbows, tees, straight connectors, adapters, plugs, bulkhead fittings, clips, valves and pipe. | Repairs, extensions, maintenance and common spare parts. | PM0412E1P, PM0312E1P, PM0212E1P, PM011204E1P, PM1212E1P. |
| WaterMarked Speedfit Twist & Lock | 12 mm fittings with Twist & Lock system, tap connectors, BPEX pipe and inserts. | Installations where a solution with additional locking and the WaterMarked range is required depending on market/regulations. | PEM0412W2P, PEM0312W2P, PEM0212W1P, PEMSTC12142P, PEMBTC12142P. |
| DIY Kits | Kits designed for upgrades and repairs in caravans and motorhomes. | Users who want a bundled solution for quick intervention. | Plumbing repair kit for caravan/RV and external kits subject to availability. |
| Auxiliary accessories | Locking clips, collet covers, tube inserts, pipe inserts, plugs and cutting tools. | To improve safety, avoid assembly errors and make maintenance easier. | PM1812R10P, PM1912E10P, TSM1209S10P, TSM1210P. |
Most common sizes for water in campervans and motorhomes
The following table summarises the sizes that most often appear in real customer enquiries and sector spare parts. The recommendation is always to measure before buying: two visually similar parts may not be compatible if one is metric and the other is in inches.
| Size | Where it appears | Usual use | What to order |
|---|---|---|---|
| 12 mm outside | Cold and hot water circuits in campers, caravans and motorhomes. | Clean water main line, taps, branches, through-bulkhead fittings, tanks and repairs. | John Guest fittings for 12 mm pipe. |
| 15 mm outside diameter | Some higher-flow systems, adapted domestic plumbing or specific conversions. | Main runs or transition to plumbing systems. | 15 mm fittings or 15–12 mm reducers if applicable. |
| 10 mm outside | Small branches, compact fittings, taps or mixed systems. | Reduce flow or connect equipment where there is less space. | 12–10 mm reducers or 10 mm fittings. |
| 3/8" male | Filtration, purifiers, dispensing, fridges, water equipment or specific accessories. | Potable water connections and auxiliary systems. | John Guest 3/8" fittings or suitable adaptors. |
| 1/4" and 5/16" | Filters, fridges, reverse osmosis, purification, vending or fine water. | Small water or drinks lines. | John Guest fittings in inches, not 12 mm fittings. |
| 1/2" BSP | Pumps, taps, filters, heaters, tap connectors and accessories. | Adapt a thread to 12 mm push-fit pipe. | 12 mm x 1/2" BSP adaptor, male, female, straight or elbow depending on the part. |
| 3/8" BSP / BSPT | Taps, filters, small adapters and threaded parts. | Connect 12 mm pipe to a smaller threaded fitting. | 12 mm x 3/8" BSP/BSPT adapter depending on thread. |
| 3/4" BSP | Tanks, filling, some larger-connection equipment and specific accessories. | Connection to tank or large thread. | Specific adaptor after checking male/female, gasket and thread pitch. |
Don’t confuse 12 mm with 1/2"
12 mm and 1/2" are not the same. 1/2" is approximately 12.7 mm, but in push-fit that difference can be critical. A fitting for 12 mm pipe is designed for 12 mm outside diameter pipe; a 1/2" fitting is designed for 1/2" outside diameter pipe or for a 1/2" thread if we are talking about BSP. Before buying, confirm whether you are measuring pipe or thread.
Why 12 mm semi-rigid tube is so common
12 mm semi-rigid pipe is a very practical solution in mobile vehicles because it combines sufficient flow, ease of installation, a reasonable bend radius and compatibility with many caravan and camper water systems. It is also usually colour-coded: blue for cold water, red for hot water and black for other applications or runs where lower light exposure is desirable.
- Very common size in caravaning spare parts.
- Easy to cut, route and secure inside furniture.
- Compatible with many push-fit parts in the sector.
- Enough for sink, shower, washbasin and small branches.
- Allows quick repairs on the road if you carry a spare.
- Actual outside diameter of the pipe.
- Tube material and maximum temperature.
- Pump working pressure.
- Whether the circuit is cold water, hot water or both.
- If it requires an insert, pipe insert, clip or support depending on the range.
Most relevant official 12 mm John Guest references
The following table expands on the previous list with official references from the 12 mm Caravan and Motorhome guide. Not all references will necessarily be available from local stock; the table is intended to identify the type of part, size and function before purchasing.
| Type of part | John Guest reference | Size | Typical use in motorhomes/campervans | Priority |
|---|---|---|---|---|
| Straight male plastic adaptor | PM011203E1P | 12 mm x 3/8" BSPT | Connection from 12 mm tubing to 3/8" female thread. | High |
| Straight male plastic adaptor | PM011204E1P | 12 mm x 1/2" BSPT | Common connection to pumps, filters, taps or accessories with 1/2" thread. | Very high |
| Male adapter with plain hose tail | PM051214E1P | 12 mm x 1/2" BSP stem | Convert a push-fit connection into a 1/2" male thread. | High |
| Equal T | PM0212E1P | 12 mm | Create branches to the kitchen, shower, washbasin or boiler. | Very high |
| Equal elbow | PM0312E1P | 12 mm | 90° turns in furniture, corners and compact runs. | Very high |
| Straight equal union | PM0412E1P | 12 mm | Repair or join two 12 mm tube sections. | Very high |
| Plug | PM0812R1P | 12 mm stem | Temporarily blank off a line or take a branch out of service. | High |
| Plastic male swivel elbow | PM091203E1P | 12 mm x 3/8" BSPT | Elbow outlet to equipment with 3/8" thread. | Medium‑high |
| Plastic male swivel elbow | PM091204E1P | 12 mm x 1/2" BSPT | Connect pump, filter or tap where there is no room in a straight line. | Very high |
| Swivel male brass elbow | RM0912141P | 12 mm x 1/2" | Threaded elbow adapter for areas with higher mechanical demands. | Medium‑high |
| Straight male brass adapter | RM0112141P | 12 mm x 1/2" BSP | 12 mm pipe to 1/2" threaded adapter with metal body. | Medium‑high |
| Bulkhead / bulkhead fitting | PM1212E1P | 12 mm | Pass through panels, cabinet walls or technical partitions. | Medium |
| Locking clip | PM1812R10P | 12 mm | Reduce the risk of accidental disconnection in areas with vibration. | High |
| Collet cover | PM1912E10P | 12 mm | Protection and identification of the fitting’s grab ring. | Medium |
| Stem elbow | PM221212E1P | 12 mm stem x 12 mm tube | Create an elbowed outlet by inserting one stem end into another fitting. | Medium‑high |
| Equal divider | RM2312E1P | 12 mm | Splitting one line into two compact outlets. | Medium |
| Female adapter for tap | CM451213FS1P | 12 mm x 3/8" BSP | 12 mm tube to 3/8" male thread connection. | High |
| Female adapter for tap | CM451214FS1P | 12 mm x 1/2" BSP | Connection from 12 mm pipe to 1/2" male thread. | Very high |
| Female adapter short thread | NCCM451213FS1P | 12 mm x 3/8" BSP short thread | Connection to parts with short thread when the standard thread does not fit properly. | Medium |
| Tube insert | TSM1209S10P | 12 mm | Internal tube support when the installation or tube requires it. | High |
| Shut-off valve | PPMSV041212W | 12 mm | Isolate pump, tap, boiler or section for maintenance. | Very high |
| Non-return valve | 12SCV1P | 12 mm | Prevent water from flowing back towards the pump, tank or sensitive section. | High |
| 5 m LLDPE tube | PE12005E1P / PE12005B1P / PE12005R1P | 12 mm black / blue / red | Short sections for repair or extension. | Very high |
| LLDPE pipe 10 m | PE12010E1P / PE12010B1P / PE12010R1P | 12 mm black / blue / red | Longer installations or partial system refurbishment. | High |
| Brass wingback elbow | 12WB1P | 12 mm x 1/2" BSP | Fixed wall or panel mounting point for tap/supply. | Medium |
WaterMarked Speedfit Twist & Lock: useful 12 mm references
The WaterMarked Speedfit Twist & Lock range adds an extra locking feature to the push-fit system. In practice, it can be of interest when you want a connection with greater closing security within a specific plumbing range. Before choosing it, it is worth checking whether it matches the tubing, standards, market and type of installation.
| WaterMarked Twist & Lock part | Reference | Size | Typical application |
|---|---|---|---|
| Straight equal union | PEM0412W2P | 12 mm | Join two sections of 12 mm tube in a repair or extension. |
| Equal elbow | PEM0312W2P | 12 mm | 90° turn inside a cabinet, under the sink or in a technical area. |
| Equal T | PEM0212W1P | 12 mm | Branch off towards tap, shower, boiler or an additional point. |
| Stem elbow | PEM221212W2P | 12 mm stem x 12 mm tube | Create an elbow that can be inserted into another fitting. |
| Straight tap connector | PEMSTC12142P | 12 mm x 1/2" BSP | Connect a 12 mm line to a tap or equipment with 1/2" thread. |
| Angled tap connector | PEMBTC12142P | 12 mm x 1/2" BSP | Connection to a tap in areas with little rear space. |
| Male brass connector | NC27712P | 12 mm x 1/2" BSP | Threaded adapter with metal part. |
| Pipe insert | TSM1210P | For 12 mm BPEX | Internal support for BPEX pipe. |
| BPEX Pipe | WM12BPEX-50C | 12 mm x 50 m | Tubing for a complete installation or major refits. |
Quick table: inches and millimetres in connectors for campers
In a mobile installation you may find metric and imperial sizes in the same circuit. This happens because pumps, taps, filters, heaters and spare parts may come from different manufacturers.
| Size | Approximate equivalence | Usual use | Warning |
|---|---|---|---|
| 1/4" | 6.35 mm | Filters, purifiers, fridges and drinking water. | It is not exactly equivalent to 6 mm. |
| 5/16" | 7.94 mm | Drinks equipment, filters and compact systems. | It is usually close to 8 mm, but it is not always interchangeable. |
| 3/8" | 9.52 mm | Water, filters, dispensing and accessories. | It is not exactly 10 mm. |
| 1/2" | 12.7 mm | 1/2" BSP threads, some imperial pipes and pumps. | Must not be confused with 12 mm metric pipe. |
| 3/4" | 19.05 mm | Tanks, water inlets, large threads and connections. | People usually talk about threads, not push-fit pipe. |
To expand equivalences, you can consult our inch-to-millimetre conversion table.
Which connector to use depending on the area of the vehicle
A motorhome or camper does not have a single connection point. The circuit usually includes fresh water tank, pump, filter, heater, taps, shower, washbasin, sink and external inlets. Each area tends to use a different type of fitting.
| Area | Common connectors | Common sizes | Practical tip |
|---|---|---|---|
| Fresh water tank | Through-bulkhead fittings, threaded adapters, shut-off valve, tube-to-hose. | 12 mm, 1/2" BSP, 3/4" BSP. | Plan access for cleaning, draining and repairs. |
| Pressure pump | 12 mm x 1/2" BSP female adapter, swivel elbow, non-return valve, filter and shut-off valve. | 12 mm and 1/2" BSP. | Do not force plastic threads and check gaskets. |
| Sink / kitchen tap | T, elbow, straight tap connector, bent tap connector, shut-off valve and reducer. | 12 mm, 10 mm, 3/8" BSP, 1/2" BSP. | Check whether the tap hose is metric, BSP or hosepipe. |
| Shower and washbasin | T, elbow, shut-off valve, adapter and reducer. | 12 mm and 10 mm. | Separate cold and hot water with colours or labels. |
| Boiler / water heater | Elbows, threaded adapters, safety valve, non-return valve and drain. | 12 mm, 1/2" BSP and manufacturer-specific connections. | Respect temperature, pressure, flow direction and drain-down system. |
| External inlet | Wingback elbow, bulkhead fitting, shut-off valve and plug. | 12 mm x 1/2" BSP. | Check mechanical fixing, leak-tightness and access to shut-off. |
| Leak repair | Straight connector, plug, elbow, tee, pipe cutter and 12 mm pipe. | Mainly 12 mm. | Carrying basic spares on the road can prevent a long stop. |
Connection to water pumps: Shurflo, Whale, Reich and similar
12 V water pumps for mobile vehicles are usually connected to semi-rigid pipe using threaded adapters, hose or specific connectors. In many installations a 1/2" BSP thread appears, so the 12 mm x 1/2" BSP female or male adapter, straight or elbow, is one of the most common ways to connect semi-rigid pipe to the pump inlet or outlet.
- 12 mm x 1/2" BSP male or female adapter.
- 12 mm x 1/2" BSP/BSPT swivel elbow.
- Shut-off valve before or after the pump.
- Pump filter or pre-filter.
- Non-return valve if required by the design.
- Straight couplings for repair.
- Safety clips or pipe supports.
- Check whether the pump has a male or female thread.
- Measure whether the outlet is 1/2" BSP, 3/8" BSP or another size.
- Do not overtighten plastic threads.
- Use a suitable seal if the connection requires it.
- Depressurise the circuit before disassembly.
- Do a leak test before closing the cabinet.
Connection to taps, sink, washbasin and shower
In camper plumbing many formats are mixed: taps with braided hose, flexible tube, BSP thread, barb or direct connection. That’s why it’s not enough to ask for “a John Guest for a tap”: you need to know whether it mates to 12 mm rigid tube, to an internal hose, to a male thread, to a female thread or to a smaller branch.
| Situation | Probable part | Example reference | What to confirm |
|---|---|---|---|
| Tap with 1/2" male thread | Tap adaptor female 12 mm x 1/2" BSP | CM451214FS1P or PEMSTC12142P | Type of seal, thread length and available space. |
| Tap with little space behind | Angled tap connector | PEMBTC12142P | Elbow orientation and tube bend radius. |
| Equipment with 3/8" thread | Tap adaptor female 12 mm x 3/8" BSP | CM451213FS1P | Whether the thread is standard or short thread. |
| Branch to tap and shower | Equal T 12 mm + shut-off valves | PM0212E1P / PEM0212W1P | Separation of cold/hot water and flow direction. |
Useful photo to identify the fitting
To choose correctly, prepare a clear photo of the old fitting, a photo of the equipment it connects to, the tube’s outside measurement with callipers and, if there is a thread, a photo of the thread with a diameter reference. This prevents confusing 12 mm, 3/8", 1/2" BSP, 15 mm, male, female or short thread.
Connection to heaters, boiler and hot water
For hot water you must check temperature, pressure and material compatibility. Some John Guest fittings are designed for domestic cold and hot water, but not all connectors in all ranges are suitable for every temperature or environment. In boiler-type heaters there may also be safety valves, automatic drains, check valves and accessories specific to the manufacturer.
| Point to check | Why it matters | Recommendation |
|---|---|---|
| Maximum temperature | Hot water requires compatible pipe and fittings. | Use fittings and tube suitable for domestic hot water and check the technical datasheet. |
| Pump pressure | Pressure spikes can reveal leaks. | Check working pressure and condition of seals. |
| Safety valve | Protects the heater and allows draining. | Do not bypass it or replace it with a generic fitting without proper criteria. |
| Non‑return valve | Prevents unwanted backflow between cold and hot water. | Install only if the schematic requires it. |
| Technical access | The boiler is usually located in enclosed spaces. | Allow for inspection and disassembly. |
| Pipe inserts | Some tubes need internal reinforcement. | Use a tube insert or pipe insert when indicated by the range or tube type. |
How to correctly install a John Guest push-fit connector
Most leaks in push-fit fittings are not due to the fitting itself, but to a bad cut, oval tube, tube not fully inserted, burrs, lateral stress, forced thread, incorrect seal, or wrong size.
1. Depressurise the circuit
Switch off the pump, open a tap and release pressure before undoing any connection.
2. Measure the pipe on the outside
Use callipers if possible. Don’t buy by intuition: 12 mm, 3/8" and 1/2" can be confused.
3. Cut square
Use a tube cutter. A crooked or chewed cut can damage the internal seal.
4. Remove burrs
The outside of the tube must go in clean, without deep scratches or deformation.
5. Use insert if required
Some tubes or product ranges require an insert to keep the tube round and reinforce the connection.
6. Push fully home
Push the pipe straight in until you feel the internal stop of the fitting.
7. Pull gently to check
Check that the collet has gripped the pipe and that it does not come out.
8. Lock if applicable
Fit the clip, collet cover or engage Twist & Lock depending on the range used.
9. Pressure test
Switch on the pump and check for leaks before closing panels, furniture or access hatches.
10. Check after sailing
After moving the vehicle, check that there are no drips and no stress on the connections.
Vibration and movement: the critical point in vehicles
In a fixed installation, the tube hardly moves. In a motorhome or campervan, the circuit is subject to vibrations, twisting and temperature changes. That’s why it’s important to secure the tube properly, avoid lateral stress on the fittings, use clips where appropriate and leave gentle curves instead of forcing angles.
Recommended emergency kit for campervan
A small selection of fittings can solve many issues during a trip: leak due to a cut tube, broken elbow, cancelled section, pump replacement or the need to shut off a line.
| Item | Recommended quantity | Function |
|---|---|---|
| 12 mm straight connector | 2 units | Repair a cut or extend a line. |
| 12 mm elbow | 2 units | Solve changes of direction in tight spaces. |
| 12 mm tee | 1 unit | Create or repair a branch. |
| 12 mm shut-off valve | 1 unit | Isolate a section or appliance. |
| 12 mm check valve | 1 unit | Prevent water backflow when the system requires it. |
| 12 mm plug | 1–2 units | Temporarily blank off a tube or branch. |
| 12 mm x 1/2" BSP adapter | 1 male and 1 female | Connect a pump, filter, tap or threaded accessory. |
| Clips / collet covers | Various | Locking and identification of connections. |
| Tube inserts | Various | Pipe reinforcement where applicable. |
| 12 mm blue/red tubing | 1–2 metres or short coil | Replace a damaged section. |
| Tube cutter | 1 unit | Make straight, safe cuts. |
Common mistakes when buying John Guest connectors for campers
| Error | Consequence | How to avoid it |
|---|---|---|
| Measure the tube internally | A fitting of the wrong size is purchased. | Always measure the outside diameter of the pipe. |
| Confusing 12 mm with 1/2" | The pipe will not go in or it leaks. | Distinguish metric tube, imperial tube and BSP thread. |
| Not knowing whether the thread is male or female | The adapter does not fit the pump or tap. | Confirm thread type before ordering. |
| Mixing up BSP with BSPT or NPTF | Incompatible thread, leak or forced assembly. | Check thread type and original part. |
| Reusing marked or deformed pipe | The internal seal may not seat properly. | Cut a new, straight section before connecting. |
| Do not use a tube cutter | Crooked cut, burrs and leaks. | Use a John Guest pipe cutter or suitable tool. |
| Forcing plastic threads | Cracks, leaks or breakage of the fitting. | Tighten carefully and use a compatible gasket. |
| Using water fittings for gas or fuel | Serious risk of incompatibility and safety issues. | Use only components specifically designed and approved for that application. |
| Not securing the tube | Vibration and stress on the fitting. | Use clips, supports and stress-free routing. |
What to buy at Install Beer to repair or install water in a motorhome
Install Beer works with John Guest every day in real installations for drinks, water, filtration, gas and technical systems. For motorhome and camper customers, the most useful selection is usually focused on 12 mm fittings, threaded adaptors, valves, check valves, tubing and cutting accessories.
| Need | Recommended product | Internal link |
|---|---|---|
| View the full John Guest range | Push-fit fittings, valves, adapters, pipes and accessories. | John Guest collection |
| Search fittings by type | Elbows, tees, straight connectors, reducers, check valves and adapters. | Connectors and fittings |
| Connect or replace lines | Food-grade tubes and hoses compatible with water or beverages. | Food-grade tubing |
| Cut pipe correctly | John Guest pipe cutter for a clean, square cut. | John Guest tube cutter |
| Isolate a section | John Guest shut-off valve for maintenance or repair. | John Guest shut-off valve |
| Adapt to BSP thread | Male adapters, female adapters or swivel BSP elbows. | 12 mm x 3/8 BSP swivel elbow |
| Connect to hose | John Guest pipe-to-hose adapter. | Pipe-to-hose adapter |
Not sure which connector you need?
Send us a photo of the fitting, the outside measurement of the pipe and the equipment it connects to. We’ll help you tell apart 12 mm, 15 mm, 3/8", 1/2" BSP, BSPT, male, female, elbow, T, valve or adapter.
Buy John Guest Check the sizeFrequently asked questions about John Guest connectors for motorhomes and campers
What tube size is most used in motorhomes and campervans?
The most common size in fresh water circuits is 12 mm OD semi-rigid tube. You may also find 15 mm, 10 mm, 3/8" or 1/2" depending on the equipment and installation.
Are 12 mm and 1/2" the same?
No. 1/2" is approximately equivalent to 12.7 mm. In push-fit fittings that difference can cause incompatibility or leaks. In addition, 1/2" may refer to pipe or to BSP thread, so it must be confirmed.
What’s the difference between BSP, BSPT and NPTF?
BSP and BSPT are common thread standards in plumbing and hydraulic fittings; BSPT usually indicates a tapered thread. NPTF is another thread standard. They must not be mixed without checking compatibility, sealing, and gasket.
How do I know if I need a male or female fitting?
It depends on the part you want to connect. If the pump or tap has a male thread, you will need a female adapter. If the part has a female thread, you will need a male adapter.
Can I use John Guest on hot water in a camper?
Yes, as long as the chosen fitting and tube are suitable for potable hot water and operate within the pressure and temperature limits specified by the manufacturer.
What is a Twist & Lock fitting?
It is a John Guest Speedfit range with an additional locking mechanism. In addition to the push-fit connection, it incorporates a twist system that helps secure the connection when correctly installed.
Do I need safety clips or collet covers?
Not always, but in mobile vehicles they are recommended in areas with vibration, strain or difficult access. They help prevent accidental disconnections and can also be used to identify lines.
Do I need an insert or sleeve inside the pipe?
It depends on the type of tube and fitting. Some systems require it to reinforce the connection; others do not. It is advisable to check the recommendation for the specific range and the type of piping.
Are these connectors suitable for butane, propane or diesel?,
No. This guide focuses on water circuits and compatible fluids. For gas, fuel or regulated installations, specific components approved for that use must be used.
Which connector do I need for a Shurflo pump or similar?
Many pumps use 1/2" BSP threaded connections, but you must check the model. In many cases a 12 mm x 1/2" BSP female adapter or a 12 mm x 1/2" swivel elbow is used to connect 12 mm semi-rigid pipe.
Can I mix John Guest with Whale or Reich?
There may be installations where brands coexist, but you must not assume automatic compatibility. You need to confirm outside diameter, tolerances, tube type, need for insert, working pressure and temperature.
Can Install Beer help me identify the fitting?
Yes. As official John Guest distributors in Spain, we can help you identify sizes and connectors if you send us photos, the tube’s outside diameter and details of the equipment it connects to.
Technical note: this guide focuses on fresh water systems and applications compatible with push-fit fittings. It must not be used as an instruction manual for gas, fuel, brakes, critical circuits or systems subject to specific approval. Before modifying a motorhome, campervan or caravan, always confirm compatibility, pressure, temperature and applicable regulations.