I worked for Parker Mobile Hydraulics Group for 20+ years and the only "negative " thing I can say about Swagelok is that a lot of their stuff is designed for instrumentation applications and tends to carry a higher price tag than Parker . However , Parker also makes an instrumentation fitting .... however , in a high vibration area application , try to use an industrial grade compression fitting as it will work as well and shouldn`t cost as much as an instrumentation fitting . A problem I have seen in extreme vibration applications with bite type fittings is that where they bite can become a stress riser and possible failure point .... stay with compression type fittings. However , both fittings are first class .
I personally prefer flare fittings for
oil and fuel .
Doesn`t mean there are any problems with the others , just my preference .