Once replace portend of fitting of EQ-FL-## by EQ-Fit-14-14P for 1/4” tube , you need to replace 11mm PTFE Gasket for sealing 1/4 BSPP Connectors (EQ-ORing-PTFE11) in the joint as well.
Please consider to have Seals metal threads to prevents leakage for MTI Flange (MTI-SEAL-MT)