HP cartridges 950, 950XL, HP 951 and HP 951XL has a valve at the outlet, that is where usually refills are made. A common needle, with hole at the tip, It is not good for this type of recharging, pea “pellet” valve cover ink outlet. Furthermore, a metal needle may damage the mechanism. Because of this I made the acquisition of this Kit 4 Connectors Bicos Pressurizar Cartridges Hp Pro, which are plastic and has a small opening on the side where it is possible to inject the ink and remove air from the cartridge.
With the InkTec inks for HP cartridges 940, 940XL, 942XL, 950 e 950XL e o Kit 4 Connectors Bicos Pressurizar Cartridges Hp Pro, now only missing the syringes. Yes, I know that any pharmacy sell, but I found in AliExpress some that comes with a long needle (10cm) to facilitate the removal of ink liters. For now are there in limbo Internal Revenue Service in Curitiba. I will speak of them when they arrive.