Revised: September 27, 2020 @ 4:30 PM.

Background Information

This is an existing installation by a national builder. I had to dig up this section for another reason and found a PEX splice. I wanted to determine if I need to do something to better protect the PEX pipe before covering this backup.

Side Rant: It may have been installed by code, inspected and approved, but code is a minimum standard. Sometimes minimum standard is fine. Sometimes, the inspector misses it or the installation is altered after inspection.

I may decide to buy the tools or decide to hire a plumber (if I can find one) with the correct tools to fix any problems before I re-bury the line. Let me be the judge of what is too expensive.

Questions

Does PEX pipe that is buried in the ground need to be protected? If so, how?
Does PEX pipe fittings / splices buried in the ground need to be protected? If so, how?
How should the PEX pipe be protected as it is going through the PVC sleeve penetrating the footing/foundation? It appears that the PVC could cause chafing of the PEX over time via expansion / contraction process.
The writing on the PEX says, "Pure Flow". Is that PEX-B?

PEX Splice

The PEX Splice appears to be a plastic fitting with copper crimp rings.

Pureflow PEX Writing

Note: I noticed that as I was cleaning the pipe, the writing was coming off the PEX Pipe. The dirt was acting as sandpaper. So I have be very careful as I was cleaning the dirt away from the PEX so that I could get a good picture of the writing on the PEX.

PureFlow Water Systems Installation Manual - June 2009

Source: https://www.houseneeds.com/upload/pdf/viega-pexsystemmanual.pdf`I did a search and found "PureFlow Water Systems Installation Manual".

When direct burying PureFlow fittings, PEX Press fittings do not need to be wrapped; however, Brass PEX Crimp fittings do. When Brass PEX Crimp fittings are put in contact with ground soil by direct burial, it is the position of Viega, that these brass fittings and copper crimp rings be securely wrapped using self-fusing, fully cured silicone rubberlike tape with a minimum 0.020" thickness.

Contact a Viega representative for additional information on approved wrapping materials.

Viega PEX Water Systems Installation Manual -

Source: https://www.pexuniverse.com/uploads/literature/viega-pex-installation-manual.pdf

Viega PEX Crimp fittings (Eco Brass and Polymer) and their crimp rings shall be securely wrapped with tape meeting the following criteria for direct burial installations.
Self-fusing
Formaldehyde-free
Fully cured silicone tape
Minimum of 0.020" thickness
The wrap is available from Viega (part number 15320).

** Repair coupling tape (PN: 15320) **

Viega Website: https://www.viega.us/en/products/Catalog/Heating-and-Cooling-Systems/Heating-and-Cooling-Solutions/Couplings/Repair-coupling-tape-2890-4US.html

** Product Instructions - Viega PureFlow Coupling Repair Wrap **

Vendor instructions to using the "Coupling Repair Wrap": https://www.viega.us/content/dam/viega/aem_online_assets/download_assets/us/pihc_560939_1119_coupling_repair_wrap_enesfr.pdf

Note: Viega Wrap appears to be similar to the SharkBite Wrap idea provided in the "jwh20"'s answer below.