2PCS 4mm One Way Aluminium Fuel Valve, Non Return Check Valve Suitable for Petrol Diesel Oil Water,for Car Carburettor Low Pressure Systems

nice little one way valves for various systems, good build quality and they work, good value for money as you get two.

Some many years ago when I was having a problem with the fuel supply to a diesel engine I decided the problem was air getting into the fuel line when the engine was not used for some time. This caused starting to be impossible with this particular Injector pump and required me to bleed the system. I thought the obvious answer was to put in a one way valve to stop the fuel flowing back into the tank. I was assured by a diesel expert that this was a terrible idea and that one way valves had no place in a fuel system.It wasn't until some years later that I discovered that my Racor fuel filter contained a check valve. So much for the self proclaimed expert.There are a number of reasons why you might wish to install such a valve in your fuel system. Needing to disassemble parts of it from time to time springs to mind. These valves are nicely made and very good value for money. I wish I'd had them all those years ago.

rather bulkier than expected

Good value check valves for low pressure automotive use. Nicely finished and work well.