How do rotary fittings work?

[Spev]

So I see there are some rotary fittings. This means that they can swivel and rotate at certain points. I was wondering how these work and how they stay leak free when they rotate? Also if someone could brief me on all the different types of more "special" fittings like this. Right now all I have are normal compression fittings. I'm setting up my loop this week and was trying to find out some better options than all normal compression.

[Enderman]

They use a high quality o-ring that allows it to turn while staying water tight because the rubber (i think its something synthetic, nor real rubber afaik) slides on the metal, but its tight enough to prevent water molecules from slipping between the o-ring and metal.

[Spev]

They use a high quality o-ring that allows it to turn while staying water tight because the rubber (i think its something synthetic, nor real rubber afaik) slides on the metal, but its tight enough to prevent water molecules from slipping between the o-ring and metal.

Ya, ok and as long as it say "rotary" that means it spins right? (for example a 90 degree fitting) because some of them are just solid.

[whipcreambeast]

They turn both directions... WOOP WOOP

[Enderman]

Ya, ok and as long as it say "rotary" that means it spins right? (for example a 90 degree fitting) because some of them are just solid.

yup