What Plumbing Fittings Do I Need for a Camper Van Water Tank?
A Simple Builder Guide to Ports Valves and Plumbing Connections
One of the most intimidating parts of building a camper van water system is figuring out fittings. Most water tank problems do not come from the tank itself. They come from incorrect fittings, poor planning, or mismatched plumbing components.
This guide breaks down exactly what fittings are commonly used with camper van water tanks, why most tanks use two 1/2” NPT ports and two 1 1/2” NPT ports, and how to build a clean reliable plumbing setup without overthinking it.
Why Most Camper Van Water Tanks Use 2 x 1/2” and 2 x 1 1/2” NPT Ports
Most van water tanks are designed around standard ½” PEX pipe. Two 1/2” ports are typically used for supply and return lines. These connect to pumps which feed the sinks, showers, and water heaters.
The 1 1/2” port is used for drainage. This larger size allows water to exit the tank quickly and prevents clogs from hair soap or debris. Any extra spin weld is often used for a vent or to add float sensors.
This layout keeps plumbing simple, serviceable, and compatible with readily available fittings.
Understanding Spin Welded Tank Ports
Many high quality water tanks use spin welded fittings molded directly into the tank. These ports accept threaded NPT fittings, which allows builders to choose brass or PVC adapters and transition cleanly to PEX without permanent glue joints. This makes the system easier to service and modify later.
Choosing a Plumbing Method Before Buying Fittings
Before buying fittings, decide which PEX method you are using.
- Crimp PEX is the most common in van builds because it is reliable, affordable, and does not require expensive tools.
- Expansion PEX offers flexibility but requires a costly expansion tool which has a price of around $500.
This guide assumes a crimp based PEX system since that is what most builders use and what can save you cost on your DIY build.
Common PEX Fittings Used in Camper Van Water Systems
Below is a list of the most commonly used fittings when plumbing a fresh or gray water tank. These are examples many builders use, not requirements.
1/2" NPT to PEX Male (Straight)
Here's an example from Amazon. Shown as sharkbite, available in crimp & expansion.
1/2" NPT Male to 1/2" NPT Male (90 Degree Elbow)
Here's an example from Amazon. Shown as sharkbite, available in crimp & expansion.
Dump Valve
Here's an example from US Solid. Shown as 1/2", available as 1 1/2".
1 1/2" Into Tank (Straight)
Here's an example from Amazon.
1 1/2" Into Tank (90 Degree Elbow)
Here's an example from Amazon.
1 1/2" From Sink (90 Degree Elbow)
Here's an example from Amazon.
1 1/2" From Sink (Straight)
Here's an example from Amazon.
1 1/2" Flex Hose
Here's an example from Amazon.
Planning Fittings Before Installing Tanks
The best time to plan fittings is before tanks are mounted. Starting with the pressure or gravity fill and knowing where lines will run and where valves will live prevents awkward plumbing and unnecessary adapters.
Dry fitting components before crimping saves time and frustration.
Final Thoughts on PEX Fittings for Camper Vans
PEX plumbing does not need to be complicated. Using standard sizes and common fittings keeps your system reliable, affordable, and easy to service.
When tanks are designed around two half inch supply ports and a large drain port, builders gain flexibility without locking themselves into proprietary components.
Good planning matters more than fancy parts.
