I'm looking for a small device that I have in my imagination but I've no idea what it's called! Can anyone help?
I need it to seal a small (2.5 mm diameter) water pipe with pressure difference of up to 30 kPa. I need to be able to stick a needle (or small tube) in and suck out the water with a pump or syringe (not important what exactly) in order to get rid of any air bubbles in the system. It needs to stay sealed, before, during and after insertion of the needle! Similar I guess to a spors ball valve or a sports drink container. But it needs to be small (about 0.5-1 mm)!
I imagine a small circular stiff rubber seal split into "leaves" like a pie. When the needle goes in, these "leaves" get pushed inwards but stay sealed. It may have a medical application.
Does anyone know what I'm talking about? It's driving me crazy!