Blowing out lines in spillover spa

[Pool_DIY_Student]

I have a question about blowing out lines in a fiberglass spillover spa when closing a pool.
Is it safe to go in this order:

1. With the spa's water level below jet receptacles, blow out and plug all air lines (except one).
2. Add water to cover the drain and airlock it.
3. Blow out the return line.
4. Blow out the bubbler and plug the last air line.

Specifically, after step 1, can water from the drain and return lines reach the empty air lines, or are they not connected?

Currently, I do step 1 last out of precautions, which is inconvenient because half of the jet receptacles are underwater.

Thanks in advance for your suggestions.

 

[ajw22]

Depends how your spa was plumbed. Usually a manifold connects the air and the water lines at the jets.

How do you plug the air lines?

If you airlock the air lines with blower pressure then water will not go back into the air line.

 

[Pool_DIY_Student]

Appreciate your explanation, ajw22.

Here is the update:

Depends how your spa was plumbed.

I have a Regal spill-over spa by Viking with 8 Waterway Poly Jet 218-6010 shown below

How do you plug the air lines?

In step 1, I will use the Cyclone Pool Line Blower to blow out all 8 water feeds and plug 7 of the water jet receptacles.
In step 4, I will run the bubbler (BLOWER SILENCER), which pushes out the remaining water from the air feed through the last jet receptacle.

In looking at your schema, can I conclude that the Water Feed and Air Feed lines are not connected to the drain line (which I will airlock on step 2) and the return line, which is used to add water to the spa (which I will blow out on step 3)?
In this case, water from the bubbler on step 4 cannot enter the drain or return lines (and vice versa ). Correct?

Thanks,