A couple years ago I set out to create the most complicated e30 oiling system known to man. One of the lessons learned during that effort is that clever choices re. fittings made a big difference in how well the plumbing worked.
The best kind of fitting is an AN swivel fitting. AN fittings are highly tolerant of R/R. Swivel fittings allow you to easily adjust the directions of the hoses. In my early efforts I underestimated the significance of both of these issues.
The worst kind of fitting is NPT because they are good at neither of the above.
In the middle is a non-swivel AN.
Murphy’s rule of fittings is “any kind of fitting that has an angle will be entirely wrong once fastened up tight”. So if you don’t have a swivel, you’re, ah “hosed”. Pun intended. Of course.
Also…you can save a lot of money on plumbing by using steel hydraulic JIC fittings instead of aviation oriented aluminum AN fittings. We’re talking 90% cheaper here, made all the more significant by the fact that inevitably you end up with fittings you don’t use.
Instead of a half dozen interations of buying expensive AN fittings mail-order to make the latest idea work…and the first couple plumbing ideas never work…I was instead able to head to a local hydraulic repair shop, peruse their bins of JIC fittings and get what I wanted immed. So not only did I save a lot of $$, but it was very efficient.
The merits of AN apply equally to JIC, except that JIC is even more rugged because it’s steel or brass.