Ok I'm clear with how you mean the fitting. I've got luer-lock needles, but my syringes have been luer slip, so friction fit. With the 510, if you have the needle set high, then it can't suck back juice below the top of the needle. Through the adapter with a longer needle the same principle would apply. With the check valve this adds a fair amount of complication, but could also be an important feature. If you have a solid plan for this and want to go through the effort then hey, go for it.