This Whale One-Way In-Line Valve 13mm sits on the suction side of your pump and suits 12.5 mm ID hose, so it helps the pump hold prime instead of letting water run back to the tank. You get steadier flow when your pump valves start to tire, which matters on weekend trips where a few lost litres a minute can slow filling sinks or tanks in the van.

The valve uses a plastic body in a compact straight profile to slip into hose spaces only a few centimetres long. It matches standard caravan plumbing that runs around 12–13 mm ID flexible hose, so swaps are simple if you upgrade pumps or layouts. Internal restriction stays low for small pumps that work under roughly 3 bar, which suits most Aussie touring water systems from the coast to hotter inland parks.

• Whale one-way in-line non-return valve
• Intended for suction side of water pumps
• Helps maintain pump prime between uses
• Supports systems where pump valves are weak
• Suits 12.5 mm internal diameter hose
• Plastic construction with white finish
• Compact straight in-line body for tight spaces
• Suitable for caravan and RV freshwater plumbing
• Works with typical small pump flow rates
• Simple cut-in installation using hose clamps

Q: Can this valve be installed on the pressure side of the pump?

No, it is intended for the suction side of the pump. The internal layout is sized for inlet conditions where pressure is lower than on the outlet line. Fitting it on the pressure side can add unnecessary restriction. Keeping it on the suction side helps the pump maintain prime and supports the role of the valve as a non-return check.

Q: Will this valve fit standard 13 mm caravan water hose?

It suits 12.5 mm internal diameter hose, which is commonly used in caravan plumbing. Many hoses sold as 13 mm have an internal diameter close to 12.5 mm. As long as your hose measures around that ID, standard clamps should secure it. If the hose is significantly larger, the fit may not be reliable.

Q: Do I need special tools to fit this in-line valve?

No, standard hose clamp tools are usually enough. You cut the hose, push each end onto the valve barbs, and secure with appropriate clamps. Checking for leaks after installation with the pump running is important. A basic screwdriver or nut driver typically handles most common clamp types.

Q: Is this valve suitable for fresh water use in caravans and RVs?

Yes, it is supplied as a plumbing fitting for caravan and RV water pumps. It sits in typical freshwater suction lines sized to 12.5 mm ID hose. The plastic construction is standard for light-duty water plumbing. As with all freshwater gear, regular inspection and flushing help keep the system in good condition.

• Install inline on the suction side of the pump
• Match to hose with 12.5 mm internal diameter
• Use with compatible caravan and RV water pumps
• Position close to the pump inlet for best prime retention