understanding Nylo-Seal fittings

[jeffsvan]

Team,

I have used Swagelok fittings before and have used the nuts with the tiny two-part locking ferrules.


Trying to understand the components of a Nylo-Seal fitting and how they lock together.



What is the difference between the Cap and the Insert?

Which goes first and do they need to be oriented a certain way?

and I assume the nut is the unit that they sit inside and you tighten with a wrench.

There is a Poly-Flo insert and a Nylo-Seal insert?

See my attached photo from spruce catalog.

Can someone please explain how they assemble?

thanks

[PaulvS]

The cap is to block off a line, so will probably not normally be needed, and the insert is to support the tube from collapsing when the nut is tightened. Dwg 36 for RV-7 has a diagram for how to assemble. If using high pressure Parker tube there is no need for the insert. The various brands of tube have their own inserts, the diameters may vary slighty.

[scsmith]

The little insert that you put inside the tubing to help support it is really beneficial. With those in place I never have any leaks, even in static pressure lines that are usually at a slight vacuum compared to surroundings.

The fittings are rather bulky but worth it for the total confidence in tight static systems.

I have not had good luck with the plug-in type fittings for slight vacuum situations like static systems. I don’t recommend them.

[jeffsvan]

This is for a static system.

Is this correct?

[PaulvS]

The order of assembly looks correct though I prefer a neat square cut with a sharp blade on the end of the tube. The end in the photo looks a bit ragged, it may be OK. Push the insert in as far as it will go.

[jeffsvan]

Ordered the proper NYLO fittings and tubing from spruce.
Cut new tubing. re-assembled.
Used a syringe/hose to check entire pitot/static system.
Rock - solid.

All is well.
Thank you kindly for the replies.