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Item works great Excellent customer service dispatched straight away parcel delivery timing depends on the couriers unfortunately
3rd order by Sharon from NSW
Gas fittings and hoses used in Australian caravans and motorhomes use several different thread types. The confusing part is that the thread name is not the same as the measurement you take with a ruler or vernier. A 1/2" BSP male thread, for example, measures roughly 21mm across the outside of the thread.
This page is a plain-English guide to identifying the common threads so you can order the right hose, adapter, or fitting. It is not installation advice. Gas work in an RV must be carried out by a licensed gas fitter.
All threaded gas components on our site show other parts that connect to them below the product description. If you are matching parts online, use those connected-product links as a check before ordering.
Measure carefully:
BSP means British Standard Pipe. BSP threads are common on caravan gas and water fittings. The sizes are imperial, but the measured diameter will not match the name of the thread.
For gas, BSP threaded joints must be sealed with an approved gas thread sealant or gas-rated thread tape by a licensed gas fitter. Water fittings may use the seal method suited to that water fitting.
A familiar household example is a garden tap. Many garden hose fittings include a 3/4" BSP to 1" BSP adapter.
The size quoted for BSP threads is based on the old internal bore size, not the outside diameter of the thread.
Click here to print a BSP thread sight guide to lay your thread on.
Male BSP: measure the outside of the male thread. The male thread is generally tapered, so it gets tighter as it is screwed in.
| Measured male OD | BSP thread name |
|---|---|
| 9.5mm | Male BSP 1/8" |
| 13mm | Male BSP 1/4" |
| 16mm | Male BSP 3/8" |
| 21mm | Male BSP 1/2" |
| 26mm | Male BSP 3/4" |
| 33mm | Male BSP 1" |
Female BSP: measure the inside of the female fitting.
| Measured female ID | BSP thread name |
|---|---|
| 8mm | Female BSP 1/8" |
| 11mm | Female BSP 1/4" |
| 14mm | Female BSP 3/8" |
| 19mm | Female BSP 1/2" |
| 24mm | Female BSP 3/4" |
| 31mm | Female BSP 1" |
SAE 45 degree flare fittings are identified by the angled flare at the end of the male fitting. These screw into an SAE nut on the end of copper pipe or a gas hose.
The seal is made on the 45 degree flare, not on the thread. Do not use thread tape on SAE flare seats.
When used with copper pipe, the pipe is flared to 45 degrees. The nut stays on the pipe and the flared copper creates the seal against the brass fitting.
Measure the outside diameter of the male thread to identify the male SAE fitting.
| Measured male OD | SAE thread name |
|---|---|
| 11mm | Male SAE 1/4" |
| 13mm | Male SAE 5/16" |
| 16mm | Male SAE 3/8" |
Measure the inside diameter to identify the nut. SAE nuts swivel and have an inverted flare inside.
| Measured female ID | SAE nut name |
|---|---|
| 10mm | Female SAE 1/4" |
| 11mm | Female SAE 5/16" |
| 14mm | Female SAE 3/8" |
The nut shown is a 5/16" nut because it fits on a 5/16" pipe. A typical caravan or motorhome gas installation often uses 5/16" copper pipe, but larger installations may need 3/8" pipe. Your gas fitter should determine the correct pipe size for the appliances and run length.
POL fittings are used on larger gas cylinders and have a left-hand thread. Many male POL fittings have a rubber O-ring or seal and must not be over-tightened.
POL is a cylinder connection, not the same thing as an SAE flare, BSP thread, or bayonet fitting.
Primus-style cylinder threads are different again. One important difference is that gas only flows after the fitting is fully inserted into the cylinder.
3/8 inch left-hand gas cylinder threads are often called Companion threads, but other brands use this style as well.
Bayonet fittings are used for removable gas appliances. The female bayonet fitting supplies the gas and comes in one common size. Use a rubber cap if the fitting is exposed to dust or dirt.
A bayonet fitting is not a POL fitting. If you are adapting a BBQ or portable appliance to a caravan bayonet, confirm the appliance connection type and have the final gas setup checked by a licensed gas fitter.
Inverted flare fittings are commonly used at the end of gas pigtails that connect to a changeover valve. The seal is made by the flare seat and does not require thread tape.
Gas leaks are serious. Use this guide to identify parts before ordering, then use a licensed gas fitter for RV gas installation, alteration, and leak testing.
Item works great Excellent customer service dispatched straight away parcel delivery timing depends on the couriers unfortunately
Have bought from caravansplus on more than one occasion, found the process easy, quick, reliable and good value each time.
⭐⭐⭐⭐⭐ I’m so grateful this business exists in Queanbeyan! It can be so difficult to find all those little caravan bits and pieces we needed, so I was thrilled to discover Caravans Plus. The gentleman behind the counter was incredibly helpful and provided great service. I placed my order in the morning online, and it was ready for collection the same day. I ordered a few different pieces because I wasn’t sure which one would best suit our needs. When I returned the items I didn’t need, the refund was processed almost immediately. Fantastic service, friendly staff and so convenient to have a business like this in Queanbeyan. Highly recommended! 👏