This single use packet of thread locking compound will help you replace old fittings and apply only a few drops to pressurized threads. Any pressurized threads should receive a joint sealant of some kind whether you choose teflon tape or thread locking compound. This medium thread locking compound is meant to allow fitting and accessories to be uninstalled. Allow 24 hours for the thread locking compound to set and dry for optimal sealing power and you will be worry free that your system will not leak. Teflon tape is easy but threadlock is secure and has an excellent track record in eliminating leaks as its liquid state penetrates threads and acts as a glue.
 
For NPT and BSP threads, Veloci Performance recommends 2-3 drops of thread locking compound.